The Chronostratigraphy of the Last Glacial Cycle Recorded in Loess-Palaeosol Sequences from Western and Central Europe"

“The chronostratigraphy of the Last Glacial cycle recorded in loess-palaeosol sequences from Western and Central Europe"

Von der Fakultät für Georessourcen und Materialtechnik der

Rheinisch-Westfälischen Technischen Hochschule Aachen

zur Erlangung des akademischen Grades eines

Doktors der Naturwissenschaften

genehmigte Dissertation

von M.Sc.

Jörg Zens

aus Düren-Birkesdorf

Berichter: Univ.-Prof. Dr. rer. nat. Frank Lehmkuhl

PD Dr. rer. nat. Martin Kehl

Tag der mündlichen Prüfung: 02. Juni 2017

Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar.

TABLE OF CONTENTS | III

Table of contents

Table of contents ...... III List of figures ...... VI List of tables ...... IX Abbreviations ...... X Abstract...... 12 Zusammenfassung ...... 14 1 Introduction ...... 16 1.1 Scientific background and motivation ...... 16 1.2 Objectives and outline ...... 17 2 Current state of research ...... 20 2.1 Luminescence dating: a brief overview ...... 20 2.1.1 Basic principles of luminescence dating ...... 21 2.1.2 Determination of the equivalent dose ...... 23 2.1.3 Anomalous fading and the pIRIR signal of elevated temperatures ...... 25 2.1.4 Total dose rate and its contributors ...... 26 2.2 Loess definition ...... 26 2.3 Loess chronostratigraphy ...... 27 2.4 Proxy data for an integrated event-stratigraphy of LPS ...... 30 2.4.1 Greenland ice core data ...... 30 2.4.2 Eifel Laminated Sediment Archive ...... 32 3 Study area and location of sites ...... 34 3.1 Ringen ...... 36 3.2 Romont ...... 41 3.3 Frankenbach ...... 44 3.4 Garzweiler-Borschemich ...... 46 4 Loess-Palaeosol Sequences at the Northern European Loess Belt in Germany: Distribution, Geomorphology and Stratigraphy ...... 49 4.1 Introduction...... 49 4.2 Loess and geomorphologic setting ...... 53 4.3 Loess distribution and regional setting ...... 57 4.3.1 Distribution of loess in Germany ...... 58 4.3.2 Lower Rhine Embayment (LRE) ...... 59 4.3.3 Northern foreland of the Harz Mountains (FHM)...... 61 4.4 Loess stratigraphy...... 64 4.4.1 Stratigraphical and chronological framework of the last glacial cycle ...... 66

IV | TABLE OF CONTENTS

4.4.2 Stratigraphical specifics and selected key sections from the Lower Rhine Embayment (LRE) ...... 69 4.4.3 Stratigraphical specifics and selected key sections from the northern foreland of the Harz Mountains (FHM)...... 72 4.5 Geomorphological position and palaeoclimate as steering factors for loess preservation...... 74 4.5.1 Loess preservation and accumulation as a function of the geomorphological position ...... 74 4.5.2 Stratigraphy and palaeoclimate implications ...... 76 4.6 Conclusions ...... 78 5 The Eltville Tephra (Western Europe) age revised: integrating stratigraphic and dating information from different Last Glacial loess localities ...... 81 5.1 Introduction...... 82 5.2 The Eltville Tephra ...... 84 5.2.1 Appearance, properties and distribution ...... 84 5.2.2 Stratigraphical position and importance as a marker bed ...... 86 5.3 Material and methods ...... 89 5.3.1 Luminescence dating ...... 89 5.3.2 Integrating age information from different localities for stratigraphic marker beds ...... 90 5.3.3 Data selection ...... 91 5.4 Results ...... 92 5.4.1 Luminescence dating of the Eltville Tephra ...... 92 5.4.2 Eltville Tephra age estimates ...... 95 5.5 Discussion ...... 95 5.5.1 Timing of the Eltville Tephra ...... 95 5.5.2 Chronological, palaeoenvironmental and stratigraphical implications...... 97 5.6 Conclusions ...... 101 6 OSL chronologies of palaeoenvironmental dynamics recorded by loess-palaeosol sequences from Europe: Case studies from the Rhine-Meuse area and the Neckar Basin . 103 6.1. Introduction...... 104 6.2 Stratigraphic and chronological framework ...... 106 6.3 Regional setting and study sites ...... 110 6.3.1 Romont West and East ...... 110 6.3.2 Ringen ...... 112 6.3.3 Garzweiler-Borschemich ...... 112 6.3.4 Frankenbach ...... 113 6.4 Methods ...... 116 6.4.1 Fieldwork and sampling strategy ...... 116 6.4.2 Luminescence dating ...... 116 6.4.3 Grain size analysis ...... 117 6.5 Results ...... 118 TABLE OF CONTENTS | V

6.5.1 Luminescence characteristics ...... 118 6.5.2 Sedimentology and geochemistry ...... 121 6.6 Discussion ...... 124 6.6.1 Luminescence dating ...... 124 6.6.2 Chronostratigraphy and palaeoenvironmental implications ...... 129 6.7 Conclusions ...... 140 7 Synthesis ...... 142 Danksagung / Acknowledgment ...... 147 References ...... 151 Appendix ...... 182 Supplementary material Chapter 4 ...... 182 Supplementary material Chapter 5 ...... 210 Supplementary material Chapter 6 ...... 215

VI | LIST OF FIGURES

List of figures

Fig. 1: The basic principle of luminescence dating using the example of aeolian deposits. .. 20 Fig. 2: Schematic and simplified principle of luminescence in mineral grains based on the energy-band model...... 22

Fig. 3: Comparison of bleaching rates of different luminescence signals...... 23

Fig. 4: Two approaches to generate dose response curves and to calculate the De...... 24 Fig. 5: Overview of loess distribution and selected LPS from Western and Central Europe dated by different luminescence dating techniques...... 28

Fig. 6: Correlation of proxy data from the LPS Dolni Vĕstonice...... 31

Fig. 7: Compilation of the ELSA Stacks and the landscape evolution zones (LEZ)...... 33

Fig. 8: Location of the investigated loess sections within the framework of the CRC 806. . . 35 Fig. 9: Topographic overview of the Ringener clay pits and the location of the investigated and published LPS...... 37

Fig. 10: Drawing of the eastern wall investigated by Henze (1998)...... 38

Fig. 11: Photos from several sections of the Ringen site...... 39

Fig. 12: Stratigraphy of the Ringen profile...... 40

Fig. 13: Cross-section of the geological situation at the Romont quarry...... 41

Fig. 14: Stratigraphy and geomorphological position of the Romont profiles...... 43 Fig. 15: Pedostratigraphic situation in the south-eastern corner of the nature reserve Frankenbacher Gravel (Bibus, 1989)...... 45

Fig. 16: Stratigraphy, photo (A) and geomorphological setting of the Frankenbach profile. 46 Fig. 17: Stratigraphy and geomorphological setting of the Garzweiler-Borschemich profile...... 48

Fig. 18: Distribution of loess and loess derivates...... 51

Fig. 19: Modern annual precipitation and dominant modern soils on loess in Germany...... 53 Fig. 20: Schematic models showing three conditions under which loess deposits may form...... 55

Fig. 21: North-south section along the Rhine River...... 58

Fig. 22: Loess distribution in the Lower Rhine Embayment...... 60 LIST OF FIGURES | VII

Fig. 23: Generalized West-East profile from the Meuse River towards the Rhine River and the mountain area of the Bergisches Land...... 61

Fig. 24: Loess distribution in the northern foreland of the Harz Mountains...... 63 Fig. 25: NE-SW-Profile from the ice margin of the Saalian Warthe stadial towards the Harz Mountains...... 63

Fig. 26: Simplification and comparison of the loess stratigraphies...... 66

Fig. 27: Selected and simplified loess sections from Lower Rhine Embayment...... 71 Fig. 28: Selected and simplified loess sections from northern foreland of the Harz Mountain ...... 73

Fig. 29: Distribution map of the Eltville Tephra...... 84

Fig. 30: Photos of the Eltville Tephra from Ringen...... 85 Fig. 31: Simplified and generalized loess stratigraphy for the last glacial cycle in Western and Central Europe with the position of the ET...... 88

Fig. 32: Albanico plots of the De distribution from the investigated samples...... 94 Fig. 33: Probability density functions for 200.000 runs from samples above and below the ET...... 96 Fig. 34: Comparison and correlation of different archives and proxy data connected to the ET as chronostratigraphic marker...... 97 Fig. 35: Location of the investigated loess-palaeosol sequences in the European loess belt...... 106 Fig. 36: Compilation of simplified stratigraphic schemes and absolute chronologies from Northern France, Belgium and the Lower Rhine Embayment and their correlation to Greenland interstadials of the NGRIP ice core...... 109 Fig. 37: Simplified stratigraphies of the investigated LPS and position of luminescence samples...... 114

Fig. 38: Photos displaying the EG and LPG sediments from the investigated LPS...... 115

Fig. 39: Typical quartz dose response and decay curves for the investigated samples...... 118

Fig. 40: Results of preheat-plateau and first-IR stimulation temperatures tests...... 119 Fig. 41: Summary of results from OSL dating, grain size analysis and CaCO3 determination...... 123

Fig. 42: Example for the change in the ΔGSD signal at sedimentary breaks...... 124

Fig. 43: Elemental contents and Al/Si ratio for the LPS Romont West...... 126

VIII | LIST OF FIGURES

Fig. 44: Portable OSL signals from Romont West and East...... 129 Fig. 45: Transect of selected LPS from Northern France towards the Czech Republic and their correlation by palaeosols, periglacial features and OSL dating...... 131 Fig. 46: Composite profile for the investigated section and correlation of palaeosols to NGRIP and the landscape evolutions zone of the ELSA Vegetation stack...... 132

Fig. 47: Photos of potential thermokast erosion features from Romont West...... 134

LIST OF TABLES | IX

List of tables

Tab. 1: Generalized sequence of the SAR-based measurement protocols for quartz and the pIRIR290 signal of feldspars applied in this thesis...... 25 Tab. 2: Summary of dosimetry data...... 90 Tab. 3: Luminescence ages used for age calculation...... 92 Tab. 4: Results of luminescence dating...... 93 Tab. 5: Results from computing ages for the ET...... 95 Tab. 6: Summary of dosimetry data...... 120 Tab. 7: Summary of dating results from the investigated samples...... 121

X | ABBREVIATIONS

Abbreviations

Loess section studied in the CRC 806 Pedostratigraphic units: Central Europe Ach = Achenheim BöS = Böcking Soil Att = Attenfeld BS1-5 = boreal soils Erk = Erkelenz E0-5 = Erbenheim Soils Fb = Frankenbach ES = Erbach Soil Garz = Garzweiler EU = Eben Unconformity Gra = Grafenberg EZ = Eben Zone Hck = Hecklingen G = gley / tundra gley Rge = Ringen KrL = Kripp Layer RS = Remagen-Schwalbenberg LoS = Lohne Soil Rom = Romont LS = Leonard Soil Ta = Talheim NEZ = Niedereschbach Zone Zil = Zilly MHZ = Mosbacher Humus Zone S1-3 = Sinzig Soils Loess section with reliable OSL R1-5 = Remagen Soils chronologies Rb = Reisberg Soil Ari = Ariendorf Dat = Datthausen Pedostratigraphic units: Northern France DV = Dolni Vĕstonice HBS = Havrincourt brown silts Gau = Gaul/Weilbach HCD = Hermies colluvial deposits GK = Grub-Kranawetberg LBS = Lower Boreal Soil Hav = Havrincourt UBS = Upper Boreal Soil KW = Krems-Wachtberg Nus = Nussloch Chronostratigraphy Ost = Ostrau EG = Early Glacial Sel = Seilitz GI = Greenland Interstadial Str = Stratzing GS = Greenland Stadial Töc = Tönchesberg H1-5 = Heinrich Events LEZ = Landscape Evolution Zone Pedostratigraphic units: Belgium LGM = Last Glacial Maximum EU = Eben Unconformity LPG = Lower Pleniglacial HCR = Humiferous Complex of LPS = Loess-palaeosol sequence Remicourt MPG = Middle Pleniglacial HS = Harmignies Soil NEA-GS = north-eastern Atlantic Greenland HV = Harveng Soil Stadial LV = Les Vaux Soil OIS = Oxygen Isotope Stage KC = Kincamp Soil UPG = Upper Pleniglacial KL = Kesselt Layer M-C = Maisisères-Canal humic horizons Geographical terms MP = Maplaquet Soil DM = Dehner maar NC = Nagelbeek Complex LRE = Lower Rhine Embayment NTH = Nagelbeek Tongued Horizon FHM = foreland of the Harz Mountains RHH = Riemst Humic Horizon WEVF = West Eifel Volcanic Field RT = Rocourt Tephra EEVF = East Eifel Volcanic Field VSG = Villers-St-Ghislain Soil WHM = Whitish Horizon of Momalle

ABBREVIATIONS | XI

Luminescence dating De = equivalent dose DRT = dose recovery test DRtot = total dose rate IR = infrared IRSL = infrared stimulated luminescence MAAD = Multiple-Aliquot-Additive-Dose MAR = Multiple-Aliquot-Regenerative- Dose OSL = optical stimulated luminescence PHT = preheat-plateau test pIRIR = post-infrared IRSL PM = polymineral pOSL = portable Optical Stimulated Luminescence Q = quartz TL = thermoluminescence WC = water content

Miscellaneous ΔGSD = difference of grain size distribution GSI = grain-size index ELSA = Eifel Laminated Sediment Archive RI = refraction index

12 | ABSTRACT

Abstract

Loess-palaeosol sequences (LPS) are valuable terrestrial archives for the reconstruction of past environmental and climatic conditions especially on a regional scale. The Western and Central European subregions of the European loess belt are characterised by thick and richly structured, but discontinuous sequences. Unconformities are common features and impede the inter-site and supraregional comparison as well as the construction of comprehensive (chrono-) stratigraphic models. Hence, the inclusion of more reliable numerical age information for the sediments holds great potential to increase our understanding of past climate condition and changes.

The majority of the available luminescence age from LPS show shortcomings in accuracy and precision compared to luminescence ages obtained from modern optical stimulated luminescence (OSL) methods. Because reliable OSL data is still only available for a small number of LPS many chronostratigraphies still rely on data produced under outdated standards. This implicates a higher temporal uncertainty and challenge every proxy data based correlation to other archives of climatic changes.

The main objective of this thesis is to improve the chronological knowledge of LPS by comparative OSL dating on quartz and feldspar. A total number of 46 ages were generated from loess sections from eastern Belgium (Romont), the Lower Rhine Embayment (Garzweiler), the Lower/Middle Rhine transition (Ringen) and the Kraichgau (Frankenbach). The results are not sensitive to the choice of which mineral is analysed and verified the reliability of the established chronologies. However, feldspar minerals embedded in reworked soil sediments are prone to incomplete bleaching during high-magnitude low-frequency erosive processes. This is reasoned by the lower bleachability rate. This leads to age overestimation which makes their usage to construct chronologies challenging.

A part of the OSL data was included in a dataset of OSL ages compiled from multiple LPS to calculate the age of the Eltville Tephra (ET) by Bayesian age modelling. The modelling results show a precise and reproducible age, in contrast to the scatter of individual ages from the same stratigraphic position. For the first time it was possible to show a connection between LPS and the Eifel Laminated Maar Archive (ELSA) by the temporal accordance between the ET age and a distinct peak in the volcanic mineral content of the Dehner dry maar. By integrating the volcanic mineral content into the stratigraphic model, the ET age was refined to ± 24.2 ka (previous, ~24-20 ka). It appears that the widely distributed ET is only preserved as cryptotephra within the Eifel maars, which may have been caused by a rapid uplift of the ash associated with a storm moving in westerly direction.

By means of OSL ages as well as stratigraphic evidence and grain size data, a composite profile was generated and compared to reference loess records for specific sediment sequences with reliable OSL chronologies. It allows for a refinement of the ABSTRACT | 13 chronostratigraphy of the recently published lithostratigraphic schemes from Northern France, Belgium, the Lower Rhine Embayment and Central Europe, which inhere weak numerical age control. The integration of Greenland ice core data and the ELSA Stacks into the composite profile enabled to develop a proxy data based event-stratigraphy supplementing previous attempts.

The integrated stratigraphical model reveals, with reservation, similar proxy data patterns between the individual records. The compiled OSL chronologies shows a temporal correspondence between climate warming signals recorded in Greenland ice cores and palaeosols in Europe. However, there is no indication that every soil formation is connected to a single Greenland interstadial (GI), but rather to a bundle of GIs. In addition, the duration and magnitude of temperature change of GIs are not indicative for the type and intensity of soil formation.

Increasing dust influx into Greenland recorded in ice cores and the higher aeolian activity in Europe inferred by loess sedimentation and/or coarser grain sizes was very likely caused by large-scale atmospheric circulation patterns dominating both regions. The main phases can be identified during the second half of the Lower Pleniglacial (LPG), the Heinrich events 4 and 3, and the Greenland stadial-2 (GS). The high loess accumulation rates during the second half of the Upper Pleniglacial (UPGb) in front of the European Low Mountains seems to be decoupled from the atmospheric circulation patterns controlling the dust influx to Greenland. Proxy data from the Dehner dry maar and climate modelling indicate increasing easterly winds likely caused by persistent high-pressure systems situated above the Scandinavian Ice Sheet.

The integration of the ELSA Stacks reveals a coupling with sedimentary successions in loess. The specific palaeosols (tundra gleys, boreal and arctic brown soils) correlate with the landscape evolution zones defined from the ELSA Stacks. Phases of frequent flood layer occurrence corresponds with unconformities in LPS. They are likely caused by a low vegetation coverage during a climate deterioration towards more cold and humid conditions. The flood cluster after the two main pedogenetic phases of the Middle Pleniglacial, the early stage of the UPG and the UPGa/b boundary is responsible for the lack of important stratigraphic information in most LPS from Europe, especially in the Lower Rhine Embayment. Here the sensitivity of the flat topography to extensive erosion is reflected by the low number of in-situ Upper Palaeolithic findings (Aurignacien and Gravettien) and high find concentrations in reworked sediments (in particular in the Kesselt Layer).

14 | ZUSAMMENFASSUNG

Zusammenfassung

Löss-Paläobodensequenzen (LPS) sind herausragende terrestrische Archive für die Rekonstruktion der regionalen Klima- und Umweltgeschichte. West- und Mitteleuropa als Teilgebiete des Europäischen Lössgürtels werden charakterisiert durch mächtige, feinstratifizierte, diskontinuierliche Lösssequenzen. Diskordanzen treten häufig auf und erschweren den regionalen und überregionalen Vergleich zwischen Lössprofilen ebenso wie die Entwicklung von umfangreichen (chrono-) stratigraphischen Modellen. Daher bietet die Einbindung von numerischen Altersinformationen ein großes Potential, um das Verständnis vergangener Klimabedingungen und –signale zu verbessern.

Der Großteil der verfügbaren Lumineszenzalter von LPS zeigen Mängel hinsichtlich der Genauigkeit und Präzision im Vergleich zu Altern die mit zeitgemäßen Methoden der Optisch Stimulierenden Lumineszenz (OSL) bestimmt wurden. Da belastbare OSL-Daten nur für ver- gleichsweise wenige Profile vorliegen, beruhen Chronostratigraphien häufig auf Altersdaten, die mit überholten Methoden bestimmt wurden. Daraus ergibt sich eine höhere zeitliche Unsicherheit, die jede proxybasierte Korrelation von Lössprofilen zu anderen Archiven des Klimawandels erschwert.

Das Hauptziel dieser Dissertation ist es, das chronologische Wissen über LPS anhand von vergleichenden OSL-Datierungen an Quarzen und Feldspäten zu verbessern. Insgesamt wurden 48 Alter von Lössprofilen aus Ost-Belgien (Romont), der Niederrhenischen Bucht (Garzweiler), dem Übergangsbereich zwischen Nieder- und Mittelrhein (Ringen) und dem Kraichgau (Frankenbach) generiert. Die Ergebnisse zeigen eine gute Übereinstimmung zwischen Quarz und Feldspat, was die generelle Belastbarkeit der Chronologien bestätigt. Gleichwohl zeigte sich, dass Feldspäte aus umgelagertem Bodenmaterial während eines ‚high- magnitude low-frequency‘ Erosionsevent von partieller Bleichung betroffen sein können. Dies begründet sich auf eine schlechtere Bleichbarkeit von Feldspäten, was zu einer Alters- überschätzung führen kann und somit die Nutzung für Chronologien erschwert.

Ein Teil der generierten OSL-Alter wurde in einen Datensatz von OSL-Datierungen von mehreren LPS integriert, mit dem anhand von Bayesischer Altersmodellierung das Alter der Eltville Tephra (ET) neu berechnet wurde. Das Modellergebnis zeigt eine hohe Präzision und Reproduzierbarkeit im Vergleich zur Streuung der Einzeldaten. Zum ersten Mal war es möglich, eine Verbindung zwischen LPS und dem Eifel Laminated Sediment Archive (ELSA) anhand der zeitlichen Übereinstimmung mit einem diskreten lokalen Maximum in den vulkanischen Mineralen im Dehner Trockenmaar herzustellen. Die Integration dieser Korrelation in das stratigraphische Model erlaubte es das Eruptionsalter von dem bisher angenommenen Alter von 24-20 ka auf ±24.2 ka zu verfeinern. Die ET scheint in den Maaren der Eifel nur als Kryptotephra erhalten geblieben zu sein, was auf eine rasche Aufnahme der Asche durch intensive, nach Westen ziehende Stürme hindeutet. ZUSAMMENFASSUNG | 15

Anhand von OSL-Altern, stratigraphischen Belegen und Korngrößendaten wurde ein idealisiertes Profil erstellt und mit wichtigen Referenzstandorten mit belastbaren OSL- Chronologien für bestimmte Sedimentsequenzen verglichen. Dies erlaubt eine Verbesserung der Chronostratigrapie der kürzlich publizierten Lithostratigraphien für Nord-Frankreich, Belgien, die Niederrheinische Bucht und Mitteleuropa, die bisher zum Teil auf schwacher numerischer Alterskontrolle beruhten. Die Integration von Eisbohrkerndaten aus Grönland und den ELSA-Stacks in das idealisierte Lössprofil erlauben die Entwicklung einer Proxydaten-basierten Event-Stratigraphie, die frühere Ansätze ergänzt.

Das integrierte stratigraphische Model zeigt mit Einschränkungen vergleichbare Muster in den Proxydaten der einzelnen Archive. Die OSL-Chronologie deutet auf eine Überein- stimmung zwischen Erwärmungsphasen aufgezeichnet in Grönland Einbohrkernen und der Bildung von Paläoböden in Europa hin. Allerdings zeigt sich, dass nicht jedes Grönland Inter- stadial (GI) mit einer eigenen Bodenbildung einher geht und zum Teil mehrere GI dafür verantwortlich sind. Darüber hinaus ist die Dauer und Temperaturmagnitude eines GIs nicht indikativ für den Bodentyp und die Intensität der Bodenbildung in Europa.

Die erhöhte äolische Aktivität, die anhand verstärkter Akkumulationsraten in Grönländischen Eisbohrkernen und LPS in Europa dokumentiert ist, wurde sehr wahrscheinlich durch großräumige atmosphärische Zirkulationsmuster gesteuert, die beide Regionen gleichermaßen dominierten. Die zweite Hälfte des unteren Pleniglazials (LPG), die Heinrich Events 4 und 3 und während das Grönland-Stadial (GS) 2 sind die Hauptphasen der Lösssedimentation. Die mächtigen Lössablagerungen der zweiten Hälfte des Oberen Pleniglazials (UPGb) im Vorfeld der europäischen Mittelgebirge erscheinen entkoppelt von dem atmosphärischen Zirkulationssystem zu sein, das Grönland dominierte. Proxydaten des Dehner Trockenmaares und Klimamodellierung deuten auf eine zunehmende Ostwindkomponente hin, womöglich bedingt durch ein stabiles Hochdrucksystem über dem Skandinavischen Inlandeis.

Die Integratation der ELSA-Stacks zeigt eine Verbindung mit den Sedimentabfolgen im Löss. Die Bildung von charakteristischen Paläoböden (Tundragleye, boreale oder arktische Braunerden) korrelieren zeitlich mit den Landscape Evolution Zones der ELSA-Stacks. Phasen mit häufig auftretenden Flutlagen korrespondieren mit Diskordanzen in LPS. Sie werden wahrscheinlich begünstigt durch eine dünne Vegetationsbedeckung in Phasen klimatischer Verschlechterung mit kalten-feuchten Bedingungen. Die Flutcluster nach den Hauptbodenbildungsphasen des Mittleren Pleniglazials (MPG), im frühen UPG und an der UPGa/b Grenze sind vermutlich verantwortlich für einen Mangel an stratigraphischen Informationen in vielen LPS in Europa, insbesondere in der Niederrheinischen Bucht. Die Sensitivität einer flachen Landschaft zu flächenhafter Erosion zeigt sich in der geringen Dichte von in-situ Fundstellen des Jungpaläolithikums (Aurignaciens und Gravettiens) und der hohen Fundkonzentration in umgelagerten Sedimenten (z.B. der Kesselt Lage).

16 | INTRODUCTION

1 Introduction

1.1 Scientific background and motivation

“… a given chronostratigraphy is best viewed as a hypothesis.”

(Skinner, 2008)

The understanding of the climatic and environmental changes as driving forces for the dispersal and population dynamics of anatomically modern humans out of Africa into Europe is a key objective of the Collaborative Research Centre (CRC) 806 ‘Our Way to Europe – Culture-Environment Interaction and Human Mobility in the Late Quaternary’. Along the migration trajectories, terrestrial and lacustrine archives are investigated to reconstruct the environmental conditions and threshold values (e.g. vegetation, temperature, moisture, food supply), which may have been crucial for the decision of hunter-gatherer societies to either adapt to abrupt climatic changes or to leave an area in favour of more promising habitats (e.g. Maier et al., 2016). In this context, Western and Central Europe especially the Rhine-Meuse area serves as sink for migration processes but also as a northern frontier during the first occupation of Homo sapiens around 40-30 ka ago BP (e.g. Holzkämper and Maier, 2012a,b; Pirson et al., 2012). The retreat towards southern refugia during the Last Glacial Maximum (LGM) and the subsequent resettlement clearly indicate that dispersal processes were predominantly driven by climatic changes.

To gain better insight in this cause and effect relationship, it is important to combine existing geoarchives to develop an integrated comprehensive model of the climatic and palaeoenvironmental evolution to which dispersal processes can be contextualized. For this purpose, reliable chronologies are crucial to synchronize different existing records and archaeological findings. Loess-palaeosol sequences (LPS) have proven to be suitable to study this relationship, because: (1) Many Upper Palaeolithic open air sites were found in-situ in loess deposits (e.g. Hahn, 1972, Haesaerts, 2004; Händel et al., 2009). (2) LPS are highly sensitive to climatic changes and provide detailed information on the landscape evolution on a local scale by sedimentological, geochemical and biological proxy data (e.g. Antoine et al., 2009; Zech et al., 2012; Meszner et al., 2013; Moine, 2014; Krauß et al., 2016). (3) Loess is excellently datable by optical stimulated luminescence (OSL) (e.g. Roberts, 2008; Thiel et al., 2011a; Kreutzer et al., 2012a; Fuchs et al., 2013; Antoine et al., 2014).

Since the 1980s, more than a thousand luminescence ages were generated from loess deposits from Western and Central Europe. The precision and accuracy of luminescence ages is closely linked to scientific and technological advancements at the time when the measurements were conducted. Several studies using older ‘out-of-date’ methods, such as 1 INTRODUCTION | 17 thermoluminescence (TL) and infrared-stimulated luminescence (IRSL), on multiple aliquots and without correction for anomalous fading, have shown inconsistent age estimates for the same samples (e.g. Frechen, 1999; Frechen et al., 2001). In addition, they frequently do not agree with independent age control and expected ages (e.g. Van den Haute et al., 2003; Bibus et al., 2007; Frechen and Schirmer, 2011).

The progress in OSL dating has increased the accuracy and precision of ages, e.g. by the introduction of the single aliquot regenerative dose protocol (SAR) for quartz (Murray and Wintle, 2000, 2003), correction methods for anomalous fading of feldspars (Huntley and Lamothe, 2001; Auclair et al., 2003), isolation of non/less-fading signals of feldspars (Thomsen et al., 2008; Stevens et al., 2011; Thiel et al., 2011a) and performance tests to isolate stable luminescence signal components (e.g. Murray and Wintle, 2000, 2003, 2006; Buylaert et al., 2012). Such improvements have become a part of the routine measurement procedure and hence increased the reliability of OSL ages since the early 2000s notably.

Nevertheless, ages generated in earlier periods were frequently used to develop chronological frameworks or to verify event-based correlation to other proxy data (e.g. Antoine et al., 2009; Haesaerts et al., 2016). This practice is justified by the comparatively sparse amount of reliable OSL ages measured with ‘state-of-the-art’ methods. As a consequence, the recent chronostratigraphic models have an inherent structural bias, which has to be reduced by more reliable numerical age controls. Embedded in the D1 project ’Analysis of Migration Processes due to Environmental Conditions between 40,000 and 14,000 a BP in the Rhine Catchment and Adjacent Areas of the CRC 806, this thesis aims to narrow the timing of specific phases (palaeosols, erosion, and sedimentation) of the Last Glacial cycle by comparative OSL dating, age modelling and the integration of different proxy datasets to a comprehensive model of the palaeoenvironmental evolution. Thus, an integrated proxy based event-stratigraphy is developed to which dispersal processes of Anatomically Modern Humans and Neanderthals can be contextualized.

1.2 Objectives and outline

“A robust approach to chronostratigraphy and climate proxybased event-stratigraphy is therefore crucial to furthering our understanding of processes and mechanisms involved in past environmental change.”

(Austin and Hibbert, 2012)

The main objective of this thesis is to improve the existing geochronology of Western and Central European LPS by comparative OSL dating on fine-grained quartz and feldspar and

18 | INTRODUCTION

facilitate their correlation to other proxy data archives. Numerical ages are supplemented by stratigraphic studies and grain size analysis. In a combined approach an integrated event- stratigraphy of the Last Glacial cycle is developed by combination of information from LPS and reference records of climatic changes, i.e. Greenland ice cores and the Eifel Laminated Sediment Archive (ELSA). Such a model can serve as a framework to which dispersal processes of Neanderthals and the Anatomically Modern Humans can be contextualised in future. In order to address this objectives, three studies were conducted embedded in the chapters 4, 5 and 6.

The second chapter comprises an overview of the history of luminescence techniques and the main methodological advancements (section 2.1). Following a brief introduction into loess (section 2.2), an overview of the challenges of past and recent chronostratigraphies for LPS is given (section 2.3). Since proxy-data correlation is an essential part of this thesis, an overview is given on Greenland ice core data and the ELSA Stacks (section 2.4).

The third chapter gives a brief introduction to the research area beginning with a large- scale perspective followed by a more regional viewpoint focusing on the geomorphological setting and geology of the surroundings of the studied LPS. Furthermore, a brief summary of the research history of each sites is presented. More comprehensive explanation on the study area is integrated in section 4 and detailed descriptions of the stratigraphy of the LPS can be found in section 6.3.

The fourth chapter presents the results of the first study giving an overview of the loess distribution, preservation, stratigraphy, and chronology of LPS from Central Europe. A brief comparison of local stratigraphies is presented and was unified to a general scheme. Luminescence ages of published studies were summarized to a chronological framework and palaeoenvironmental interpretation from several studies were combined to more general statements on the evolution of different time slices. The study targets the following research questions:

 What are steering factors of loess formation and its spatial pattern?  What is the current state of research in loess stratigraphy and chronology?  How does the interplay of climate, geomorphology and periglacial processes influence the resolution and preservation conditions of LPS in different areas?

The inventory compiled in the first study reveals some of the major challenges for studying LPS and their chronologies. Loess records in Western and Central Europe are discontinuous and suffer from repeating phases of erosion. In combination with imprecise and inaccurate luminescence chronologies, this challenges the construction of robust (chrono-) stratigraphies.

The first step in the improvement of the geochronology is presented in the second study in chapter 5. Here, the focus lies on the Eltville Tephra; an important marker bed of the Upper 1 INTRODUCTION | 19

Pleniglacial. The study aims to revise the Eltville Tephra age by a combination of new OSL ages directly generated from the tephra and a Bayesian age modelling approach. The results are contextualized with proxy data from the Eifel Laminated Sediment Archive and Greenland ice core data. The main research questions are:

 Does the Bayesian age modelling approach results in reproducible and accurate depositional ages for the Eltville Tephra?  Does the model results correspond with OSL ages directly from the tephra?  What are the palaeoenvironmental implications of the revised age?

The third study (chapter 6) focuses on the geochronology and environmental dynamics during the entire Last Glacial cycle. OSL chronologies and grain size proxies (GSI and ΔGSD) are presented originating from Romont (Belgium), Garzweiler (Lower Rhine Embayment), Ringen (Lower-Middle Rhine transition) and Frankenbach (Neckar Basin). The results are contextualised to European key loess section to develop a comprehensive picture of the stratigraphy and chronology of LPS from the area. This practice allows for the development of a proxy data based event-stratigraphy by correlating LPS to the Eifel Laminated Sediment Archive and Greenland ice core data. The study is motivated by the following research questions:

 Does quartz OSL and pIRIR290 ages on feldspar correspond to each other and are suitable to construct reliable chronologies for LPS?  Are their characteristic patterns in grain size data for specific time slice and locations and can they be used as stratigraphic tools to correlate various LPS?  Does the data enables reliable correlations to other reference loess section?  Are the investigated LPS and their proxy data suitable for an improved integrated event-stratigraphy in combination with other archives of climatic changes?

The overall results of the embedded studies (sections 4, 5 and 6) are summarized in the final synthesis of chapter 7.

20 | CURRENT STATE OF RESEARCH

2 Current state of research

2.1 Luminescence dating: a brief overview To reconstruct the palaeoenvironmental evolution of geomorphological systems, it is crucial to obtain reliable age information concerning phases of erosion, transport and deposition of sediments. Luminescence dating is a useful numerical dating method, which determines to determine the time elapsed since the last exposure of mineral grains (here: sedimentary quartz and feldspar) to daylight (Fig. 1). It exploits the ability of quartz and feldspar minerals to act as natural dosimeters. The luminescence signal arises from the exposure to ionised radiation induced by natural occurring uranium, thorium, potassium and rubidium in sediments and cosmogenic radiation. A fraction of the emitted energy is stored within lattice defects of the crystal structure and temporally increases until the mineral grain is exposed to daylight again. Exposure to daylight commonly occurs during erosion, transport and deposition of a mineral grain.

Fig. 1: The basic principle of luminescence dating using the example of aeolian deposits. The luminescence signal is erased (zeroed, bleached) during light exposure. If the mineral grain is buried and shielded from daylight, the signal starts to accumulate induced by the radioactive decay of uranium, thorium and potassium (emitted by α-, β and γ-rays) as well as cosmogenic radiation (c.r.). Once the sediments are reactivated and exposed to daylight, the signal is zeroed and the bleach-dose cycle starts again. Figure modified according to Aitken (1998).

The brightness of the luminescence signal depends on the number of lattice defects and the amount of radioactive radiation the mineral was exposed to since burial. The stored dose (palaeodose) is determined as the energy per mass of mineral (1 Gy = 1 J kg-1). During laboratory measurements, the intensity of luminescence emission is used to calculate the dose equivalent (De) to the total dose absorbed in nature. The emitted dose rate over time (Gy/time) can be determined directly by in-situ dosimeter measurements or indirectly by determining the concentration of radioisotopes converted into dose rates by conversion factors (e.g. Adamiec and Aitken, 1998; Guerin et al., 2011; Liritzis et al., 2013). By dividing the equivalent dose by the dose rate, the time since the last exposure to daylight can be determined (Eq. 1) (Aitken, 1998). CURRENT STATE OF RESEARCH | 21

푒푞푢푖푣푎푙푒푛푡 푑표푠푒 (퐺푦) 퐿푢푚푖푛푒푠푐푒푛푐푒 푎푔푒 (푘푎) = 푑표푠푒 푟푎푡푒 (퐺푦/푘푎) (Eq. 1)

This principle and the frequent abundance of quartz and feldspar in sediments makes luminescence dating the preferred dating method for a wide range of depositional landforms of aeolian, fluvial, lacustrine, limnic or colluvial process systems (e.g. Preusser et al., 2008). Loess deposits are well suited due to the good bleaching conditions during the transportation process and hence provide the ideal testing ground for luminescence dating (e.g. Aitken, 1998; Roberts, 2008). The large number of published studies and ages since the early applications in the 1980s reflects this (cf. Fig. 5).

In the following sections, an introduction into the basic principle and milestones of luminescence dating is provided. More detailed information on the applied measurement setup, performance tests and dose rate determination are presented in the methodological chapters of the embedded studies (sections 5.3.1 and 6.4.2).

2.1.1 Basic principles of luminescence dating The physical principle behind luminescence dating relies on the ability of non-conductive minerals, such as quartz and feldspar, to capture radiation-induced energy within crystal lattice defects (Bøtter-Jensen et al., 2003). A simplified model of the physical mechanism generating the luminescence signal is provided by the energy-band model of insulating solids (Fig. 2). In the ground state, all energy levels of the atoms are filled with electrons forming the valence band. The conduction band is freed of electrons and has a higher energy level. Both bands are separated by the so-called forbidden gap. The width of the gap determines the necessary excitation energy to transfer an electron from the valence to the conduction band (Bøtter-Jensen et al., 2003). In an ideal crystal no electrons can stay within the forbidden gap. However, natural crystals exhibit lattice defects such as oxygen vacancies or foreign atoms (Preusser et al., 2008), which act as traps with discrete energy levels within the forbidden gap, where electrons can be captured.

Once an electron is excited by ionised-radiation (Fig. 2, left), it is transferred from the stable ground state to the metastable conduction band, leaving behind a charge deficit (hole) in the valence band. The hole can move to lattice defects in the forbidden gap and form a luminescence recombination centre. Most electrons immediately release the absorbed energy and drop back into the ground state, whereas some electrons can be captured with their energy excess in lattice defects (electron traps). Once the mineral is stimulated by light or heat, the electron is transferred from the trap to the conduction band and back to a recombination centre. During this process, the excess energy is released as photons (luminescence signal) (Fig. 2). More detailed reviews on the complex physical mechanism and interactions are presented e.g. in Bøtter-Jensen et al. (2003).

22 | CURRENT STATE OF RESEARCH

Fig. 2: Schematic and simplified principle of luminescence in mineral grains based on the energy- band model. Figure modified according to Aitken (1985).

Natural minerals exhibit a complex variety of traps and recombination centers with discrete energy levels. Each of these trap types are of finite number and reach a saturation limit, where all traps are filled with electrons (Bøtter-Jensen et al., 2003). The trap types are characterized by differences in trap depth below the conduction band. The trap depth describes the amount of external stimulation energy, which is necessary to release an electron from a trap. Shallow traps can be easily evicted by natural lattice vibrations and hence have very short lifetimes (Duller, 2014). Only electron traps with a certain trap depth (>1.6 eV) are stable over geologically relevant timescales (Aitken, 1998). Only light-sensitive traps, which are bleachable by daylight exposure are suitable for luminescence dating of sediments.

Luminescence dating techniques use different stimulation sources and measurement setups to release electrons of specific sensitive traps and to record the subsequent photon emission. By artificial stimulation with heat (thermoluminescence, TL), the vibration of the crystal lattice increases and evicts electrons when a certain temperature is reached and held for a sufficient amount of time. A different luminescence technique utilise optical stimulation with visible light (green or blue OSL) or infrared light (IRSL). Electrons absorb photons and evict from the trap (Aitken, 1998).

The main advantage of optical stimulation compared to TL lies in the fact that traps sensitive to light are more rapidly depleted than those traps used for TL dating (Fig. 3; Godfrey-Smith et al., 1988). In addition, quartz OSL bleach faster than IRSL, which bleach faster than the post-infrared IRSL signals of elevated temperatures (pIRIR, cf. Thomsen et al., 2008; Stevens et al., 2011; Thiel et al., 2011a). Consequently, in nature the quartz OSL and IRSL/pIRIR signals bleach much faster than the TL signal and hence are less prone to incomplete bleaching (Fig. 3). This advantage made optical stimulation techniques the preferred methods for sediment dating purposes since their early applications to quartz (Huntley et al., 1985) and feldspar (Hütt et al., 1988). CURRENT STATE OF RESEARCH | 23

Fig. 3: Comparison of bleaching rates of different luminescence signals. TL signals from quartz and feldspars bleach more slowly than optical stimulated signals (A, from Godfrey-Smith et al., 1988). Within the range of usable optical stimulation techniques, the quartz OSL signal is more rapidly bleachable than the IRSL and pIRIR from feldspars (B, from Buylaert et al., 2012).

2.1.2 Determination of the equivalent dose

The determination of the De is conducted by the comparison of the natural luminescence signal with signals induced by artificial radiation with known doses in a laboratory. The De is determined by calculating dose response curves using an additive or regenerative method (Fig. 4). For the additive dose approach, the natural signal is measured and a stepwise increasing laboratory irradiation dose is added to the natural dose of further aliquots to construct a dose response curve. The De can be calculated by means of an extrapolation through the y-axis (Fig. 4 A, Duller, 2014). Therefore, the result is highly sensitive to the choice of the mathematical model for curve fitting (Aitken, 1998). As a result, such an approach may introduce a higher uncertainty to the analysis. For the regenerative approach, the natural luminescence signal is measured and zeroed. Subsequently, known laboratory radiation doses are added and the luminescence signal is measured. The dose points are then used to construct a dose response curve to which the natural luminescence can be interpolated (Fig. 4 B; Duller, 2014).

24 | CURRENT STATE OF RESEARCH

Fig. 4: Two approaches to generate dose response curves and to calculate the De. Red points show the luminescence signal measured after laboratory irradiation. (A) The additive dose method adds artificial radiation doses on top of the natural signal and calculates the De by extrapolation through the y-axis. (B) The regenerative method bleaches the natural signal and adds artificial radiation doses to construct the dose response curve. The natural dose is measured and De can be determined by interpolation. Figure from Duller (2014).

In the early studies making use of luminescence dating, the multiple-aliquot regenerative

(MAR) and additive dose (MAAD) protocols were commonly used to determine the De (Roberts, 2008; Duller, 2014). Many aliquots were required and divided into two groups: one for the measurement of the natural luminescence signal and a second one for the dose points of the measurement protocol. The aliquot-to-aliquot variations lead to a broad scattering of signals and a higher uncertainty ranges of the final age (Wallinga et al., 2000; Hilgers et al., 2001; Preusser et al., 2008). To solve this problem, new approaches suggest to conduct all measurements on the same aliquot in order to reduce aliquot-to-aliquot scatter (e.g. Duller, 1991, 1995; Murray et al., 1997). One shortcoming of the regenerative approach applied to single aliquots from quartz is that sensitivity changes between natural and laboratory measurements can occur (e.g. Aitken, 1998; Preusser et al., 2008), i.e. the luminescence signal per unit of absorbed radiation varies between repeated measurements (Duller, 2014).

To solve this problem, the single-aliquot-regenerative-dose protocol was initially developed for quartz (Murray and Wintle, 2000, 2003), but it was also applied to feldspar (Wallinga et al., 2000). Sensitivity changes are monitored by repeatedly measuring the luminescence response to a constant test dose (Tn, Tx) after measuring the natural (Ln) and regenerative (Lx) luminescence signals. Varying response signals to the test dose can be interpreted as a change of the underlying sensitivity. The natural and regenerated signals can then be corrected by dividing the subsequently measured test doses. This protocol adds a high degree in precision and accuracy to the existing OSL measurements of quartz and feldspar. Together with further refinements it is up to now the commonly used protocol (Roberts, 2008).

Tab. 1 shows the SAR protocol applied in this thesis for quartz and the pIRIR290 signal of feldspar (cf. section 2.1.3). CURRENT STATE OF RESEARCH | 25

Tab. 1: Generalized sequence of the SAR-based measurement protocols for quartz and the pIRIR290 signal of feldspars applied in this thesis.

Quartz pIRIR290 of feldspar

Treatment Observe Treatment Observe

1 Natural signal or give dose - 1 Natural signal or give dose - 2 Preheat (160-280 °C for 10 s) - 2 Preheat (310°C for 60 s) - 3 Optical stimulation for 40 s at 125 °C Ln, Lx 3 IR stimulation for 200 s at 50 °C Ln, Lx 4 Give test dose - 4 IR stimulation for 200 s at 290 °C Ln, Lx 5 Cut heat, 20 °C below preheat - 5 Give test dose - 6 Optical stimulation for 40 s at 125 °C Tn, Tx 6 Preheat (310°C for 60 s) - 7 Return to 1 - 7 IR stimulation for 200 s at 50 °C Tn, Tx 8 IR stimulation for 200 s at 290 °C Tn, Tx 9 IR stimulation for 100 s at 325 °C - 10 Return to 1 -

2.1.3 Anomalous fading and the pIRIR signal of elevated temperatures Anomalous fading is the phenomenon of a signal loss over time observed during laboratory measurements of the TL and IRSL signals of feldspars (Wintle, 1973; Spooner, 1992, 1994; Huntley and Lamothe, 2001). The signal loss can lead to considerable age underestimations compared to independent age control (e.g. Wintle, 1973; Huntley and Lamothe, 2001; Auclair et al., 2003). Therefore, Spooner (1994) suggested to routinely apply monitoring tests to check if a sample is affected by fading or not. Later on, several methods were developed, which allows the observation and correction for anomalous fading (e.g. Huntley and Lamothe, 2001; Auclair et al., 2003). However, the mathematical model used for anomalous fading correction is complex and the application of these methods is only reliable to correct the linear part of the dose response curve and hence is challenging with regard to doses in the exponential part.

The discovery of signals less or non-affected by fading marks an important milestone in the history of OSL dating of feldspars (Jain and Singhvi, 2001). Thomsen et al. (2008) observed that the fading rate decrease with increasing stimulation temperatures after an initial IR depletion of the IRSL signal at 50°C. These observations lead to the development of the pIRIR SAR protocol for elevated temperatures by Buylaert et al. (2009) initially for 225 °C and later on adjusted to 290°C (Stevens et al., 2011; Thiel et al., 2011a). Comparative studies indicated that fading rates of pIRIR signals are lower or even negligible and decrease with elevated temperatures (e.g. Thiel et al., 2011b). Without fading correction, good accordance was observed with fading corrected IRSL (Thiel et al., 2011a) and quartz (Stevens et al., 2011) ages, but also with independent age control (e.g. Roberts, 2012). Hence, the usage of the pIRIR signal of elevated temperatures by the usage of an adjusted SAR protocol became a standard procedure for determining reliable feldspar ages. The protocol applied to feldspar samples analysed in the context of this thesis is displayed in Tab. 1.

26 | CURRENT STATE OF RESEARCH

2.1.4 Total dose rate and its contributors The total dose rate given rise to the luminescence signal is build-up by three major components. (1) The sediment surrounding the sample emit ionised radiation by α-, β and γ- rays induced by the radioactive decay of natural occurring isotopes of uranium (235U and 238U), thorium (232Th) and potassium (40K) and to a lower degree rubidium-87. The different rays vary according to their penetration depth between ~10-40 µm for α-particles, 2 mm for β- particles and 30 cm for γ-rays (Aitken, 1998; Duller, 2014). Therefore, bulk material from a radius of 30 cm surrounding the sample is taken to determine the external dose rate. (2) The internal dose rate depends on the mineral composition and results from radioisotopes incorporated in the mineral chosen for dating. While the internal dose rate of quartz is usually negligible, it becomes important in potassium-rich feldspar, which usually is the object of feldspar dating (Duller, 2014). It is an established approach to assume a fixed internal potassium content to evaluate the contribution to the total dose rate (e.g. Huntley and Baril, 1997). It is commonly suggested that bright luminescence signal can also be related to sodium- rich feldspars (e.g. Huot and Lamothe, 2012; Smedley et al., 2012) and hence the internal potassium content can be much lower than the proposed literature values. However, the differentiation between potassium and sodium-rich feldspar is not possible within arguable effort. (3) The third contributor to the total dose rate is cosmic radiation. It can penetrate into the surface and the amount cosmic radiation contributed to the total rate depends on the geographical position, altitude and sample burial depth (Prescott and Hutton, 1994).

The total dose rate is reduced by soil water, because it absorbs the radiation differently, ultimately diminishing the radioactive energy delivered to the mineral (Duller, 2014). The water content over time is dependent on the capacity of the surrounding sediment to capture water within pores and on changes in the moisture supply. Hence, the grain size distribution and soil density have a huge impact on the capability of the sediment to capture water. Even if the water content is an essential part of the age equation, the determination over time is very challenging, especially if sediments are investigated covering arid and humid phases of the Last Glacial cycle. Therefore, it is a common approach to use the gravimetric in-situ water content or a fixed value as a constant of the average water content over time.

2.2 Loess definition The definition of the term ‘loess’ or ‘loess-like sediment’ is subject to an ongoing debate amongst Quaternary scientists (Pye, 1995; Pécsi and Richter, 1996; Smalley et al., 2011; Sprafke and Obreht, 2015). Even though loess is a widespread Quaternary aeolian sediment covering up to 10 % of the Earth’s surface (Pye, 1995) and being one of the most important archives for the reconstruction of climatic changes during the Quaternary (Muhs and Bettis, 2003), there is no commonly accepted definition (cf. Sprafke and Obreht, 2015). However, there is a broad agreement that loess is characterised by aeolian accumulation of silt-sized particles, but CURRENT STATE OF RESEARCH | 27 scientists disagree on further sufficient characteristics. This problem inheres to the variety of properties and concepts, which are used to characterize loess, e.g. by its sources, mineral composition, transport pathways, accumulation and post-depositional processes (loessification). The controversy between sedimentological and pedological perspectives on definition of loess and loess-like sediments was recently summarized and discussed by Sprafke and Obreht (2015).

A thorough and concluding discussion of an optimal definition of loess, loess-like sediments or loess derivates, would be beyond the scope of this thesis. Therefore, the definition expressed in section 4.2 whereby loess is defined as “…an aeolian, homogenous, predominantly silt-sized (20-63 µm), loose sediment where particles are weakly cemented by calcium carbonate” is adequate for the context of the thesis. In addition, the consideration of the fundamental requirements for loess formation - a dust source, sufficient wind energy for aeolian transport, an accumulation area and a sufficient amount of time (Pye, 1995) - is important to understand grain size variations and changes in the sedimentary successions. These process requirements and their counterpart in Western and Central Europe are highlighted in section 4.2 illustrated by an adjusted version of the loess formation model of Pye (1995) and in section 4.3 with a regional perspective on the Lower Rhine Embayment.

2.3 Loess chronostratigraphy Since the first systematic investigations on loess deposits from Western and Central Europe, numerous individual sections were studied and documented (e.g. Schönhals et al., 1964; Semmel, 1968; Rohdenburg and Semmel, 1971; Löhr and Brunnacker, 1974; Schirmer, 2000, 2016; Bibus, 2002; Antoine et al., 2016; Haesaerts et al., 2016). Lithological layers were identified by analysing visible patterns such as colour and sedimentary features. They were combined to local stratigraphic schemes and compared to adjacent loess areas to study the local variability of loess and palaeosols. Sections 4.4 and 6.2 include more insights on the history, challenges and major findings on loess stratigraphies from the study area and provide correlations between them.

Reliable numerical age information is a crucial prerequisite to establish robust chronostratigraphies, which allow for correlations between different areas and archives. Early chronological frameworks of loess stratigraphies were initially based on soil counting and the comparison of palaeosols with modern analogues (e.g. Remy, 1960; Schönhals et al., 1964; Rohdenburg and Meyer, 1966; Brunnacker, 1967). They were supplemented by radiocarbon dating if datable material was found (e.g. Semmel, 1967; Haesaerts et al., 1981 and references therein; Vandenberghe et al., 1998). Radiocarbon dating reaches a dating limit around 50 ka and therefore can only provides numerical ages for a limited time slice of the Last Glacial cycle.

28 | CURRENT STATE OF RESEARCH

The introduction of luminescence dating as a technique to date the burial age of sedimentary grains improves the chronological knowledge of loess deposits (Roberts, 2008). Since the early application to loess deposits in the 1980s (Wintle, 1981; Wintle and Brunnacker, 1982), far more than a thousand luminescence ages were published using different luminescence dating techniques (Fig. 5). The quality is predominantly characterized by the state-of-the art prior to the methodological milestones drawn out in section 2.2. Most chronologies of LPS are based on feldspar TL and IRSL ages measured with MAR and MAAD protocols without fading correction (e.g. Frechen et al., 2001; van den Haute et al., 2003; Frechen and Schirmer, 2011; Schirmer, 2012; Haesaerts et al., 2016 and reference therein). For some LPS, comparative high-resolution chronologies are available consisting of a hundred ages of sometimes up to four estimates per sample (cf. S4-1_Fig. 15, Frechen, 1999; Frechen et al., 2001; Frechen and Schirmer, 2011).

Fig. 5: Overview of loess distribution and selected LPS from Western and Central Europe dated by different luminescence dating techniques. The loess distribution was modified according to Haase et al. (2007). 1: loess; 2: loess derivates; 3: sandy loess; 4: maximum extent of the Weichselian glaciation according to Ehlers et al. (2004, 2011). Red dots (5) indicate the location of the loess profiles presented in this thesis. Abbreviations of these sites are explained in Fig. 8. Yellow dots (6) mark LPS dated during the CRC 806 project period. Location Zilly (Zil) and Hecklingen (Hck) were dated in the Luminescence Laboratory of the University of Bayreuth by Ch. Schmidt (Krauß, 2017). Black dots (9) mark locations dated with ‘out-of-date’ methods, i.e. MAR and MAAD of TL and IRSL without fading measurements. Green dots (7) represent LPS dated only with ‘state-of- the-art’ methods, i.e. SAR protocol was applied to quartz and feldspar samples. Feldspar ages CURRENT STATE OF RESEARCH | 29 were either determined using fading correction methods or by measuring the luminescence of the pIRIR signal on elevated temperatures. Dark green dots (8) are LPS where chronologies exist for both; ‘out-of-date’ and ‘state-of-the-art’ methods.

The results of comparative luminescence dating studies (MAR/MAAD of TL and IRSL of feldspars) have previously shown that ages derived by different approaches did not always coincide (e.g. Frechen and Preusser, 1996; Henze, 1998; Frechen, 1999; Preusser and Frechen, 1999; Frechen et al., 2001; Frechen and Schirmer, 2011 and S4-1_Fig.15). Differences were also observed compared to independent age control and expected ages (e.g. Van den Haute et al., 2003; Bibus et al., 2007; Frechen and Schirmer, 2011). The differences, in particular for the same sample, indicate potential shortcomings in the methodology that may limit its potential for the construction of reliable chronostratigraphies (cf. Bibus, 2002; Haesaerts et al., 2016). However, early luminescence studies provided first important evidence for the timing of climatic events recorded in loess deposits and were a first breakthrough for the understanding of the geochronology of the Last Glacial cycle (Zöller and Semmel, 2001).

In total, more than a thousand ages measured with ‘out-of-date’ methods stand in contrast to less than five hundred age determined taking ‘state-of-the-art’ approaches. However, it is not necessarily the case that all ages estimated before the methodological milestones are by definition incorrect or wrong. But the scientific progress in luminescence dating clearly increased the accuracy and precision of ages (cf. section 2.2). These improvements (e.g. SAR protocol, fading correction, pIRIR signal and numerous performance tests) are now part of the standard measurement procedure and hence increased the reliability and comparability of luminescence ages since the early 2000s. Recent studies were conducted using these improvements, but unfortunately several of these either contain only a few single ages (e.g. Tissoux et al., 2010; Frechen and Schirmer, 2011; Schmidt et al., 2011a; Gocke et al., 2014; Schmidt et al., 2014), target only specific layers (e.g. Thiel et al., 2011; Sauer et al., 2016; Zens et al., 2017) or show unclear luminescence properties (e.g. Klasen et al., 2015a, Fischer, 2010). Only a few studies present more comprehensive chronologies for entire LPS or specific time slices (e.g. Schmidt et al., 2011b; Kreutzer et al., 2012a; Lomax et al., 2012; Meszner et al., 2013; Zöller et al., 2013; Antoine et al., 2014).

To improve the chronostratigraphy of LPS and increase the precision and accuracy, it is common practice to use proxy data based event-correlation to other climatic archives with well-understood age models, for example deep sea sediment drill cores or Greenland ice core data (e.g. Schimer, 2000; Rousseau et al., 2007; Moine et al., 2008; Antoine et al., 2009). Comparisons correlate the pattern of proxy data from loess (i.e. grain size variations, total organic carbon, molluscs) and correlate them to patterns in other archives (cf. section 2.4). Unfortunately, such proxy data event-based correlations are not seldomly confirmed by luminescence ages determined with ‘out-of-date’ methods. Such methods suffer from a lower precision and accuracy; this challenges the reliability of these approaches. Without robust

30 | CURRENT STATE OF RESEARCH

numerical age control, these approaches have the tendency of wiggle matching. Therefore, the extension of datasets of reliable OSL ages is highly recommended and the consideration of all ages from different localities can clearly improve the robustness of such correlations.

Section 4.4 includes an inventory of the loess stratigraphy with a simplified model and a summary of average published luminescence ages from the units of the Last Glacial. This will serve as a framework to which the results and correlation of this thesis can be contextualized.

2.4 Proxy data for an integrated event-stratigraphy of LPS Reliable and well understood age models are crucial for studying past climatic and environmental changes. Proxy data based event-stratigraphy is an approach where proxy data correlated to each other by the assumption that either a direct causal relationship exists or, if different archives are used, the same external factors caused comparable proxy data patterns. The method seeks to achieve a better systematic understanding of the interaction between processes and relevance for the climatic evolution and is strongly dependent on a robust chronostratigraphy (Austin and Hibbert, 2012). Integrated stratigraphy combines multiple stratigraphic disciplines, proxy data and dating techniques creating more robust models of the chronology and palaeoenvironmental evolution (see e.g. Hilgen et al., 2003, 2014; Abdul Aziz et al., 2008; Timar-Gabor et al., 2011; Constantin et al., 2015). In loess research, several studies were conducted to correlate LPS to other archives such as pollen records, Greenland ice cores and deep sea sediments. A brief overview of the proxy data used for LPS in this thesis is given in the following sections.

2.4.1 Greenland ice core data The most important event-stratigraphy of the Last Glacial cycle in the north-eastern Atlantic region is the INTIMATE (INTegration of Ice-core, Marine and Terrestrial records) event-stratigraphy, which was recently updated by Rasmussen et al. (2014) and Seierstad et al. (2014). It comprises of three synchronized ice cores (GISP2, GRIP and NGRIP) with a highly precise chronology for the Last Glacial cycle based on ice layer counting and parallelized by volcanic ash layers (Blockley et al., 2012; Davies et al., 2014). Ice cores provided a variety of proxy data, such as δ18O as an indicator for the atmospheric temperature or dust and Ca2+ content as a result of aeolian input. The pattern of δ18O and Ca2+ was used to structure the climatic oscillations into Greenland interstadials (GI) and Greenland stadials (GS) equal to Dansgaard-Oeschger events (Dansgaard et al., 1993).

A good accordance between climatic signals derived from Greenland ice cores and LPS was observed, when palaeosols, organic matter and/or molluscs were correlated to the δ18O signal or grain size changes to atmospheric dust or Ca2+ content (e.g. sections 5 and 6; Rousseau et CURRENT STATE OF RESEARCH | 31 al., 2002; Antoine et al., 2001, 2009, 2013; Moine et al., 2008; Schirmer, 2012). It was postulated that phases of increasing atmospheric temperatures corresponds with periods of soil formation in Europe. However, such correlations are only reliable, if the duration of an interstadial is sufficient to be captured by numerical dating methods by considering their uncertainties (cf. Kadereit et al., 2013; Sauer et al., 2016). For the UPG, more dust influx to Greenland occur contemporaneous to increasing aeolian dynamics in Europe recorded by coarser grain sizes in loess deposits (Study 3; cf. Rousseau et al., 2007; Antoine et al., 2009; Gocke et al., 2014; Krauß et al., 2016). However, reliable numerical chronologies are rarely available and hence proxy data correlation was given more confidence in being sufficient. This is reasoned by the dating uncertainty, which hamper the association of soil formation to short time climatic oscillations.

Nevertheless, a good example of the possibilities of a proxy data based event-stratigraphy in combination with numerical age control is given in Fig. 6. It displays the high-resolution Early Glacial loess sequence of Dolni Vĕstonice situated in the Czech Republic (Antoine et al., 2013). All presented proxy data shows a corresponding pattern indicating a linkage between processes of climatic change and their response in terrestrial, marine and ice core records. The fine-grained quartz OSL chronology clearly strengthened the correlations (Fuchs et al., 2013), and is essential for the evaluation of the reliability of the connection. The study shows the potentials of integrating archives and proxy data to a more comprehensive model of the climatic evolution and is highly recommended for further investigations.

Fig. 6: Correlation of proxy data from the LPS Dolni Vĕstonice to the NGRIP δ18O, GRIP Ca2+(Andersen et al., 2006), sea surface temperatures from the Iberian margin (MD01-2444 core, Martrat et al., 2007; Guihou et al., 2011) and the NALPS δ18O records (Boch et al., 2011). Figure from Antoine et al. (2013).

32 | CURRENT STATE OF RESEARCH

2.4.2 Eifel Laminated Sediment Archive The Eifel Laminated Sediment Archive (ELSA) is a dataset of more than 50 lacustrine drill cores extracted from wet and dry maar lakes of the western Eifel volcanic field (Sirocko, 2016). They provide a high-resolution record of pollen and lacustrine sediments reflecting the palaeoenvironmental evolution of the last 500,000 years of the Eifel Mountains and the subjacent areas. Up to now, the last 60,000 years are evaluated and published (Fig. 7, Brunck et al., 2016; Förster and Sirocko, 2016; Sirocko et al., 2016).

The individual records were dated by 14C, 137CS, 210Pb, 39Ar/40Ar, luminescence dating, magnetostratigraphy, greyscale, varve counting and ice core tuning (Sirocko et al., 2005; Sirocko et al., 2013). The previous chronologies were improved and partly revised by ice core tuning of the total organic carbon (TOC) content from the Auel maar (Sirocko et al., 2016). The individual cores were then combined to a common ELSA record by pattern in pollen data. Another important backbone of the chronostratigraphy are visible tephra layers, which reflect time synchronous events. The ash layers are composed in the ELSA tephra stack (Förster and Sirocko, 2016).

The laminated lake sediments provides several proxy datasets, which allows to trace climatic and palaeoenvironmental changes. The ELSA vegetation stack includes the pollen data from several cores combined to a common pollen record (Fig. 7, Sirocko et al., 2016). The ELSA dust stack consists of four sediment cores and is based on grain size analysis of quartz grains (Fig. 7, Seelos et al., 2009). It gives information on wind regimes and aeolian dynamics with a seasonal resolution and allows the identification of single dust storm layers by grain size analysis (Seelos and Sirocko, 2005). Dietrich and Seelos (2010) focused on the Dehner dry maar core to additionally reconstruct wind directions for the time slice 40.3 – 12.9 ka. An updated stack was recently published by Sirocko et al. (2016). Flood events were investigated on three cores and are composed in the ELSA flood stack (Fig. 7, Brunck et al., 2016). It is suggested that these events are connected to a more open vegetation cover, which increased the erodibility and allows massive sediment influx into the maar lakes. The ELSA varve stack (Fig. 7) displays variations in the varve thickness and hence also indicates phases of increased sediment influx into the lakes; either by aeolian input or eroded sediments from the surroundings. All stacks were finally combined with further proxy data to construct landscape evolution zones (LEZ) to provide a comprehensive model for the environmental changes in the Eifel area for the last 60,000 years. CURRENT STATE OF RESEARCH | 33

Fig. 7: Compilation of the ELSA Stacks and the landscape evolution zones (LEZ). UMT: Ulmener Maar Tephra; LST: Laacher See Tephra; WBT: Wartgesberg Tephra; UT1: Unknown Tephra 1; DWT: Dreiser Weiher Tephra; UT2: Unknown Tephra 2. LcT: Leucite Tephra. Figure from Sirocko et al. (2016).

Outside of the ELSA stacks, Römer et al. (2016) presented results of heavy minerals and grain size analysis from the Dehner dry maar core for the time slice 29-12.5 ka. Key results of the study are the reconstructions of changes in wind directions and aeolian transport mechanism as well as potential variations of the source material. In addition, the content of volcanic minerals were investigated probably indicating the presence of cryptotephras in the maar sediments. Profe et al. (2016) conducted geochemical analysis on the LPS Schwalbenberg II and correlated the results to the ELSA stacks and NGRIP ice cores by proxy data. However, this attempt suffers from a weak numerical age control to verify the suggested connections between the different records.

34 | STUDY AREA AND LOCATION OF SITES

3 Study area and location of sites

The LPS studied in this thesis are situated in the region between eastern Belgium and the Kraichgau in south-western Germany. The topography is dominated by the European low mountain range (e.g. Rhenish Massif, Vosges Black Forrest, South German escarpment region, Harz Mountains). North of the orocline, vast flat plains extend to the Atlantic Ocean, the North Sea and the Baltic Sea (Fig. 8). The temperate climate is dominated by the oceanic influence of the Atlantic Ocean and the Gulf Stream with a tendency to more continental climate conditions to the East (cf. Fig. 19, Hendl, 2002). The average annual precipitation varies from below 500 mm in the rain shadow of the Harz Mountains (Thuringia basin) up to more than 1000 mm in the low mountain ranges (Fig. 19), and hence is clearly controlled by the local topography and the regional climate.

The geological bedrock shows a complex structure of Palaeozoic, Mesozoic and Cenozoic rocks, which underwent three phases of mountain building: the Caledonian, Variscan and Alpine orogeny (Walter, 2007). The Caledonian phase is of minor importance for the recent geological structure. During the Variscan orogeny, an intensive folding of predominantly Devonian rocks have taken place with SW to NE striking faults. With the end of the Variscan folding, huge parts of the area were affected by tectonic subsidence, which allows frequent phases of oceanic transgression and regression during the Perm and the entire Mesozoic with the deposition of marine deposits (e.g. Zechstein, Muschelkalk, Keuper or Cretaceous limestone). As a consequence of the Alpine orogeny, the area was affected by fracture tectonic with NW-SE and NNE-SSW striking faults dividing the bedrock into rift valleys, horst, half- horst and graben structures (Walter, 2007). The depressions were then filled with loose sediment of the Tertiary and Quaternary.

According to Liedtke (2002), the area can be divided into three major geological provinces: (1) The basement rock consists of Palaeozoic rocks and is characterized by denudation surfaces with deeply incised river valleys (e.g. Eifel Mountains). (2) The geomorphology of the Mesozoic overburden rock is dominated by escarpments, plateaus and sedimentary basins, where erodible rocks were removed (e.g. South German escarpment region, in particular the Neckar basin). (3) The unconsolidated rock consists of loose Tertiary and Quaternary deposits forming smooth and flat landscapes (e.g. Lower Rhine Embayment).

The most spatially distributed Quaternary sediment is loess. The research area is a part of the European loess belt; a continuous band of loess cover running from north-western Europe to the East European plains in front of the low mountain range, along big river valleys and within sedimentary basins (Haase et al., 2007). It was mainly deflated from the braided-river systems (Smalley, 2009), by the exposed shelf of the North Sea (cf. Smykatz-Kloss, 2003; Antoine et al., 2009). In north-eastern Central Europe, the glaciofluvial outwash plains in front of the Scandinavian ice sheet (section 4) is one of the most important contributors. In all areas, STUDY AREA AND LOCATION OF SITES | 35 the frequent reworking of older loesses (Razi Rad, 1976; Janus, 1988; Henze, 1998) occurs as a minor dust source. More insights into the spatial distribution of loess deposits is introduced in section 4.3.

In this thesis, LPS from four different research areas, namely the Hesbaye, the Lower Rhine Embayment, the Lower/Middle Rhine transition and the Kraichgau are presented (Fig. 8). A closer look at the local topography, geology and research history of the sites is presented in the following sections. Detailed explanation of the stratigraphy of the LPS are embedded in section 6.3.

Fig. 8: Location of the investigated loess sections within the framework of the CRC 806. The red dots show sites, which are investigated in this thesis. Yellow dots display LPS investigated during the last six years within the CRC 806 and which were published elsewhere. Rom: Romont West and East; Garz: Garzweiler; Erk: Erkelenz; Rge: Ringen; Gra: Grafenberg; RS: Remagen- Schwalbenberg; Zi: Zilly; Hck: Hecklingen; Ach: Achenheim; Att: Attenfeld; Fb: Frankenbach; Ta: Talheim. The black star shows the Dehner maar, an important palaeoclimatic archive used for correlations in sections 5 and 6.

Further sites were examined between 2009 and 2017 of fieldwork within the D1 project of the CRC 806 (Fig. 8). From a drill core at the Remagen-Schwalbenberg, new OSL chronologies were presented by Klasen et al. (2015a). The grain sizes of the Grafenberg drill core were investigated by Schulte et al. (2016). With the sites Zilly and Hecklingen, two LPS from the foreland of the Harz Mountains were investigated with a multi-proxy analysis to reconstruct the palaeoenvironmental evolution in a loess area close to the Scandinavian ice sheet (Krauß

36 | STUDY AREA AND LOCATION OF SITES

et al., 2016). A further local multi-proxy analysis was conducted for the Kraichgau/Neckar basin at the LPS Frankenbach and Talheim by Krauß et al. (under review). New OSL ages are now available for the LPS Attenfeld (measured by Nicole Klasen, University of Cologne) and Hecklingen and Zilly (measured by Christoph Schmidt, University of Bayreuth). These results will be presented in the PhD thesis of Lydia Krauß. Further publications are planned for the LPS Achenheim (leading author Oliver Moine, CNES) and Erkelenz.

3.1 Ringen The clay pits Ringen (Kettiger Thonwerke) are located east of the village Ringen on the southern slope of the Ringener creek valley at ~170 m asl (Fig. 9). It is situated in the undulating landscape of the ‘Grafschafter Lösshügelland’ at the transition between the Lower Rhine Embayment, the Eifel Mountains and the Middle Rhine Valley around 9 km westwards of the Rhine. The altitude of the pit vary between ~260 m and 160 m asl. The mean annual precipitation over the 1956-2014 reference period is 603 mm measured at the meteorological station Campus Klein-Altendorf Nord (University Bonn) 5 km north-west of Ringen. The land use is dominated by agriculture.

Geologically, the area is situated at the northern border of the Eifel Mountains and is dominated by NW-SE running faults dividing the underground into several blocks forming tectonic horsts, half-horsts and graben (Meyer, 2013). The underlying bedrock is dominated by alternating layers of Devonian clay-, silt- and sandstones. In tectonic depressions, Oligocene and Miocene clays were deposited as erosive products of the uplifting Eifel Mountains (Meyer, 2013). They are covered by Pleistocene loess, which can reach more than 14 m in the Ringener depression, where the investigated profile is located (Henze, 1998).

Since the 1970s several exposures were investigated in the area with the aim to contextualise the local loess deposits with the Aurignacien open-air site Lommersum (cf. Remy, 1960; Löhr und Brunnacker, 1974; Brunnacker et al., 1978) and with LPS from other loess provinces of Central Europe (cf. Rohdenburg and Semmel, 1971; Löhr and Brunnacker, 1974). For this purpose, the Eltville Tephra functioned as the key marker horizon for the pedostratigraphical interpretation of the embedded palaeosols. It is well preserved in the area with up to 5 different bands separated by thin loess layers (Löhr and Brunnacker, 1974). In this context, the first stratigraphic investigation were conducted at Ringen within an older pit south of the recent active mining area in a plateau position (Rohdenburg and Semmel, 1971; Löhr und Brunnacker, 1974). The LPS consisted of 4 m loess with three intercalated interstadial palaeosols covering tertiary clays. Later on, studies on the mineralogical composition (Juvigné and Semmel, 1981) and age of the Eltville Tephra (TL dating by Juvigné and Wintle, 1988) were conducted in the same quarry. STUDY AREA AND LOCATION OF SITES | 37

Fig. 9: Topographic overview of the Ringener clay pits and the location of the investigated and published LPS. The spatial extent of the gyttja was reconstructed according to the observations from Henze (1998) and of this study. Hillshade and topographic information adopted from the Landesamt für Vermessung und Geobasisinformation Rheinland-Pfalz (http://www.geoportal.rlp.de).

The recently active pit is situated on the lower slope of the valley and is divided by a watershed into a north-eastern and eastern exposed slope (Fig. 9). Comprehensive pedostratigraphic investigations were conducted by Henze (1998). He studied a ~80 m long exposed wall with loess deposits of up to 14.5 m thickness and Tertiary clays at the base (Fig. 10). Two important observations lead to the assessment that Ringen represents an exceptional position within the area. First of all, the Eben Unconformity and the reworked sediments of the Kesselt Layer, both typical features of the north-western European loess area, are missing. The UPGa loess gradually turns into the UPGb loess without any unconformity. It is hypothesized that this observation maybe caused by the special topographic setting of the site on the bottom of a stretched slope. An alternative explanation is that the site is in fact not included in the prevailing process regime that created the deeply incising erosion period.

38 | STUDY AREA AND LOCATION OF SITES

Fig. 10: Drawing of the eastern wall investigated by Henze (1998). The gyttja (F) reached a thickness of up to 7 m. The reduction horizon (Gr) above the gyttja is supposed to be caused by Holocene soil moisture, which have overprinted tundra gleys (GoNG) developed in loess above the gyttja. Figure from Henze (1998).

The most remarkable observation was the presence of a several meter thick silt gyttja developed in loess (Fig. 10). Fig. 11 (B, C, D and G) shows the gyttja excavated during the fieldwork in 2016. To determine the timing of the gyttja, Henze (1998) investigated random pollen samples. They contained no tree pollen, but a clear dominance of grass pollen. Mollusc analysis of a tundra gley below the gyttja showed a classical Columella columella fauna which is associated with glacial conditions. The sediments above the gyttja are assumed to be deposited during the UPG due to the presence of the Eltville Tephra, and hence the timing of the gyttja formation was concluded to have taken place during interstadial conditions of the MPG. In addition, a fossilised mammoth tusk was found within the gyttja during mining activities. However, the age span determined based on stratigraphic evidence has to be proven by numerical dating.

The forming processes of the gyttja are still subject to scientific debate. Henze (1998) suggested that either erosive processes have formed a depression on the slope or tectonic subsidence provided condition for the storage of water and organic material. The water supply could have been delivered by the southern tributary of the Ringener creek, because several, slightly rounded small gravel layer were found within the gyttja (Fig. 9). This hypothesis is strengthened by the suggested spatial extent of the gyttja. A catchment of such extent would have likely provided sufficient water supply to keep the gyttja ‘alive’. STUDY AREA AND LOCATION OF SITES | 39

Due to this remarkably feature, the position at the transition from the Lower to the Middle Rhine and ongoing mining activities, the Ringen site was reinvestigated in 2016. Along the eastern wall, several sections were investigated on the north-eastern and eastern exposed slope with an intermediate watershed. The gyttja documented by Henze (1998) was found on the eastern exposed slope suggesting a lateral extent of at least ~830 m. It shows an alternation of wet and drier phases (cf. Fig. 11 B, C, D and G) with intercalated input of terrestrial sediments (small gravel layer, cf. Fig. 11 B).

Fig. 11: Photos from several sections of the Ringen site. Photo A shows an overview of the exposed wall and the location of the investigated LPS. The gyttja is developed on the eastern exposed slope and shows multiple phases of water logging and external sediment influx (B, C and D). Photo G shows the continuing sedimentary sequence below photos B, S and D. Photo E shows the UPGa and MPG sequence of the composited profile of study three (chapter 6). The Eemian and Early Glacial sedimentary sequence is displayed in photo F. Photos: A: J. Zens; B, C, D, F: L. Krauß; E: S. Lechtaler; F: N. Fohl.

40 | STUDY AREA AND LOCATION OF SITES

The new LPS Ringen (section 6.3.2) consists of four consecutive profiles (RGE-3, RGE-6-3, 6-2 and 6-1) close to the north-eastern exposed slope (Fig. 9, Fig. 11 and Fig. 12). The uppermost profile (RGE-3) is situated on the eastern exposed slope in the periphery of the gyttja and contains the Eltville Tephra with five individual ash layers and 2.4 m of aeolian UPGa sediments above a compacted and disturbed clayish interstadial brown soil (Fig. 12 A). The remaining sections are situated close by the watershed on the north-western exposed slope and consists of 9 m of Last Glacial loess with intercalated palaeosols of the EG, LPG, MPG and UPGa spread over three consecutive profiles (Fig. 12 B, C, D, E). At a close by profile, an interglacial soil addressed to the Eemian was found below a humic steppe soil of the EG (Fig. 11, F). A more detailed description of the stratigraphy is included in section 6.3.2.

Fig. 12: Stratigraphy of the Ringen profile. The photos A-E shows the individual sections of the consecutive profile. Photo F shows root channels in UPG deposits coated by iron precipitation, which is indicative for a dense herb vegetation. The fine platy structure of the Boreal Soil 3 (BS3) is depicted in photo H. A large ice wedge cast formed during the MPG is displayed in photo G. Photo I shows a crotovina filled with loess and root channels coated with manganese precipitation within the Early Glacial humic horizons. The unit is truncated by erosion associated with a STUDY AREA AND LOCATION OF SITES | 41 channel several cm to the left (cf. photo E). Further abbreviations are explained in section 6.3.2. Photos: J. Zens.

3.2 Romont The Romont site is located on the western slope of the Geer creek valley in the C.B.R. quarry Romont (Eben/Bassenge) in the Hesbaye region (eastern Belgium) 5 km southwards of Maastricht and 2.5 km westwards of the Meuse River (Fig. 8). The Hesbayen plateau is a smoothly undulating landscape (elevation 80-200 m asl) covered with loess and bracketed by the Campine plateau in the North, the Meuse River in the East and the Condroz region in the south. The average annual precipitation for the reference period 1981-2010 is 772.7 mm (Royal Netherlands Meteorological Institute, 2013). The dominated land use is agriculture.

The geological bedrock of the area belongs to the Brabantian massif situated in front of the Rhenish massif (Ardennes and Eifel Mountains). It is build-up of Palaeozoic rocks, which are covered with thin layers of Mesozoic limestone (Cretaceous), Tertiary sands and Pleistocence gravels (Meuse), sand and loess (cf. Fig. 13, Walter, 2007). In the Hesbaye and Aachener- Limburger Cretaceous table, thicker layers of marine Cretaceous limestone are preserved close to the surface (Walter, 2007) and are subject to active mining operations in the Romont quarry (Fig. 13). Here, Tertiary and Mesozoic rocks are covered with two Pleistocene terraces of the Meuse River (Juvigné, 1992) and up to 15 m of loess (Haesaerts et al., 2016).

Fig. 13: Cross-section of the geological situation at the Romont quarry. The location of the profile is mentioned in Fig. 14. Figure translated and modified according to Juvigné (1992).

The Hesbaye loess region and the adjacent areas have a long history in loess research (e.g. Gullentops, 1954; Meijs et al., 1983; Haesaerts et al., 2016 and references therein). Some of the major loess sections of the Belgian lithostratigraphy such as Rocourt, Remicourt-Momalle or Lixhe are situated in the area. In addition, with the open-air sites Remicourt (Haesaerts et al. 1997, 1999) and Kesselt-Op-de-Schans (Van Baelen et al., 2007, 2011; Meijs et al., 2013), important Middle Palaeolithic artifacts were found in the region. Especially the LPS Remicourt has become a key reference sites for the new stratigraphic schemes of the Belgian loess

42 | STUDY AREA AND LOCATION OF SITES

sequence (Haesaerts et al., 2016) due to its high-resolution and TL dates provided by Van den Haute et al. (2003). Further pedostratigraphic studies were conducted at several pits along the Albert Canal (e.g. Meijs, 2002, 2011), where the loess deposits are believed to reach back to the late Saalian.

Early investigations at the Romont site were conducted on the geological setting of the quarry by Juvigné (1992) (Fig. 13). By studying UPG loess deposits, Schirmer (2003) defined Romont sequences as type locality of the Eben-Zone; the change from the Hesbaye (UPBa) to the Brabant (UPGb) loess separated by the Eben Unconformity and their reworked material (Kesselt Layer). Later on, further parts of the stratigraphic succession were also defined as the new loess stratotype in Belgium (Haesaerts et al., 2011b). Recent studies focused on the Chernozem-like steppe soils (Humiferous complex of Remicourt) of the Early Glacial and the embedded Rocourt Tephra (Juvigné et al., 2008). In 2011, Rixhon et al. dated one of the exposed Meuse terraces (Romont terrace) in the quarry to 725 ± 120 ka by age modelling of cosmogenic nuclide ages (10Be/26Al), which indicates that all loess deposits above must be younger. By applying geotechnical methods (cone penetration), Delvoie et al. (2016) could trace the surface of the Humiferous Complex of Remicourt, Rocourt Pedocomplex, Nagelbeek Complex and the recent decarbonation limit in the front end of the north-eastern exposed wall. The investigated LPS of this thesis is also situated at this wall.

The LPS Romont West and East are situated in slope positions surrounding the former steep hill (Fig. 14). Romont West is located on an intermediate flattering of the slope with a north-western exposure. It consists of four consecutive profiles with an overall thickness of ~11 m, whereas 10.2 m were deposited during the Last Glacial cycle. The sediments of the LPG and MPG (~4 m) shows a fine lamination indicative for intense sheet flow processes on the upper slopes and redeposition on the local flattering (Fig. 14 A, B). However, even this part was frequently affected by erosion indicated by stratigraphic gaps. The LPS Romont East is located on a stretched convex slope with an eastern exposure. It consists of 7 m of loess with intercalated palaeosols. It mainly covers the UPGa and b with the typical succession of the Eben-Zone. More detailed information on the stratigraphic situation are given in section 6.3.1.

STUDY AREA AND LOCATION OF SITES | 43

Fig. 14: Stratigraphy and geomorphological position of the Romont profiles. Photo A shows the Kincamp A/B Soil (KC a/b) at the base covered by laminated colluvium and the potential Les Vaux Soil (LV) above. Photo B shows the laminated colluvium of the Lower Pleniglacial covering the EG Humiferous Complex of Remicourt (HCR). The Kincamp A/B Soil on top of the colluvium is disturbed, probably by a thermocast event. Photo C shows the EG sequence with the Humiferous Complex of Remicourt, the Whitish Horizon of Momalle (WHM) and the Villers St.Ghislain A/B (VSG-A/B). Photo D shows the Eben-Zone and the underlying Eltville Tephra (ET). Photo E displays the lowermost interstadial palaeosols covered by a bleached tundra gley. The topographic map shows the situation prior to the excavation of the hill and is modified according to Juvigné (1992). Further abbreviations are explained in section 6.3.1.

44 | STUDY AREA AND LOCATION OF SITES

3.3 Frankenbach The nature reserve ‘Frankenbacher Gravel’ is located in ~190 m asl around 3 km westwards of the city Heilbronn and the Neckar river on a north-eastern exposed slope of a dry valley running in easterly direction into to the Lein creek valley (Fig. 16). Geographically, the area is situated in the ‘Süddeutsches Schichtstufenland’ in the eastern edge of the Kraichgau and is surrounded by the ‘Keuperbergland’. The undulating landscape is covered with loess, which reached the highest thickness in the Neckar valley (cf. Bibus, 2002). The average annual precipitation in this heterogeneous region varies between 600-700 mm (cf. Fig. 19, Bibus, 2002) and the land use is dominated by agriculture.

The geological bedrock is domianted by Mesozoic rocks, which are structured by NW-SE running faults into anticlines and depressions. At anticlines where the bedrock consists of Middle Triassic limestone, the Neckar is deeply incised forming active and abandoned meanders (Bibus, 2002). The location Frankenbach is situated in the Heilbronn depression. Here, Upper Triassic bedrock was eroded and thick layers of Middle Pleistcence gravels and sands of the Neckar River were deposited (Walter, 2007) termed Frankenbacher Gravel and Sands (Bibus, 2002). Due to ongoing tectonic subsidence, the Neckar left his river bed and the accumulation of loess have started reaching a thickness of up to 15 m at Frankenbach and 20 m at Böckingen (Bibus, 2002).

Loess deposits of the Kraichgau and middle Neckar area have a long research tradition since the early surveys in the 1920s (Bayer, 1927). Several LPS were published providing insights into the palaeoenvironmental evolution (cf. Bibus, 1989, 2002; Frechen, 1999). During this studies, the locality Böckingen was defined as the key reference profile for the pedostratigraphy of the entire area (Bibus, 2002). It contains four fossil Bt-horizons above fluvial deposits of the Neckar indicating a long temporal resolution (Bibus, 1989, 2002). However, luminescence dating studies do not support the proposed stratigraphic interpretation and yielded ages corresponding to the Riss glaciation (Zöller and Wagner, 1990; Frechen, 1999).

A comparable situation was observed at Frankenbach. The first investigations focussing on the loess stratigraphy were conducted by Bibus (1989) along ~200 m of exposed loess walls of the former quarry. Up to three fossil Bt horizons and a fourth developed in fluvial sediments corresponding to interglacial conditions were observed (Fig. 15). The properties of the loess record were more intensively studied by grain sizes analysis, geochemistry and micromorphology (Bibus et al., 2008). In addition, a study on the magnetic susceptibility of an extracted drill core were conducted by Hambach et al. (2008), who assumed that the loess deposits from Frankenbach covers the last 300,000 years.

STUDY AREA AND LOCATION OF SITES | 45

Fig. 15: Pedostratigraphic situation in the south-eastern corner of the nature reserve Frankenbacher Gravel (Bibus, 1989).

The studied LPS of this thesis is located in the north-eastern corner of the nature reserve, which was previously documented by Bibus et al. (2008). It was reinvestigated because it exhibits sediments of the entire Last Glacial cycle (Fig. 16). Special interest lied on the Lohne Soil (Fig. 16 B), which is probably connected to the first arrival of AHM into Central Europe (cf. Kadereit et al., 2013; Antoine et al., 2016). The new LPS consists of 6 m of loess covering all stages of the Last Glacial cycle except of the UPGb, which is eroded due to Holocene soil erosion. Besides the stratigraphic and chronological results presented in the third study (chapter 6), a multi-proxy analysis was conducted by Krauß et al. (under review) within the scientific background of the CRC 806.

46 | STUDY AREA AND LOCATION OF SITES

Fig. 16: Stratigraphy, photo (A) and geomorphological setting of the Frankenbach profile. Photo B shows the Lohne Soil (LoS) and the overlying strongly bleached loess with rusty bands. Photo C shows a crotovina filled with laminated colluvium, which is not visible in the surrounding sediments due to bioturbation prior to the infilling. The blue line in the topographic map shows the location of published stratigraphies by Bibus (1989, 2002) and Bibus et al. (2008). Further abbreviations are explained in section 6.3.4. The topographic map was adopted from the Landesamt für Geologie, Rohstoffe und Bergbau, Baden-Württemberg (http://maps.lgrb-bw.de/)

3.4 Garzweiler-Borschemich The LPS Garzweiler-Borschemich was located in the opencast lignite mining Garzweiler close to the former villages Borschemich and Holz in the Lower Rhine Embayment (Western Germany). It is surrounded by the low mountain range of the Rhenish Massive in the South and East and turns over into the northern German lowlands in the North. The flat topography is structured by smooth valley, e.g. of the Rur, Erft and Niers rivers and their tributaries and tectonic horsts such as the Ville and Jackerather Horst (Fig. 22). The average annual precipitation vary between 800 mm at the transition towards the low mountain range and 630 mm in the south-east in the rain shadow of the Eifel Mountains (Fig. 19). The land use is dominated by agriculture.

STUDY AREA AND LOCATION OF SITES | 47

The Lower Rhine Embayment is tectonic subsidence area, which is divided by fracture tectonics into blocks with varying rates of subsidence. The resulting horst and graben structures follow predominantly NW-SE running faults (Ahorner, 1962). The geological fundament is build-up by Devonian and Carboniferous rocks covered with up to 1000 m of Tertiary sediments including the Miocence lignite, which are the target of mining activities in the area (Walter, 2007). During the Quaternary, several terraces of the Rhine River have formed and were covered by loess after the river was fixed to their recent valleys (Boenigk and Frechen, 2006). To the North, the loess cover gradually turns over into sandy loess and sandy cover sheets (Fig. 22). More detailed information on the regional setting are given in section 4.3.2.

The mining area provides large exposures of loess deposits and were intensively investigated since decades (e.g. Remy, 1960; Brunnacker, 1967; Henze, 1998; Schirmer, 2002b; Kels, 2007; Fischer et al., 2012). These studies made it possible to trace the palaeotopography and the forming processes on large scale profiles (e.g. Lehmkuhl et al., 2015). However, even if a large amount of exposures were available, only a few luminescence ages exists providing numerical age control for the stratigraphic interpretations (Henze, 1998; Fischer et al., 2012). Thus, the chronostratigraphy of the area is mainly based on pedostratigraphy. The results of these comprehensive stratigraphic investigations yielded two key observations. Firstly, frequent phases of extensive erosion occurred in the flat plains of the Lower Rhine Embayment, which led to the observation that MPG and UPGa sediments are nearly completely missing despite of some special morphological situations on valley slopes (cf. Kels, 2007). The most important erosion event is represented by the UPG Eben Unconformity (~23.5 ka, cf. sections 4, 5 and 6). It is deeply incised into the underlying sediments, in some cases down to the Saalian. It represents a landscape changing erosion event in the area, which is traceable until Northern France (Antoine et al., 2003). The second key observation is that the Upper Pleniglacial Eben-Zone (Eben Unconformity, Kesselt Layer and E4 Soil) and the overlying UPGb (Brabant) loess with the intercalated Leonard Soil are the typical stratigraphic situation in the Lower Rhine Embayment (Schirmer, 2003).

The LPS Garzweiler-Borschemich reflects the typical succession for loess profiles in the opencast lignite mining area. The morphological position is situated on an upper slope close to a plateau position with a south-western exposure (Fig. 17 C). It has a thickness of more than 8 m, whereas 7.5 m can be attributed to the UPGb due to the presence of the Eben-Zone at the base (Fig. 17 B). More detailed information on the stratigraphy are given in section 6.3.3.

48 | STUDY AREA AND LOCATION OF SITES

Fig. 17: Stratigraphy and geomorphological setting of the Garzweiler-Borschemich profile. Photo A shows the sequence above the Kesselt Layer, which is displayed in Photo B. It shows strong solifluction by the tongues of the E4 soil mixed with the Kesselt Layer. Topographic map adopted from Geobasis NRW, Bezirksregierung Köln (https://www.geoportal.nrw/). Further abbreviations are explained in section 6.3.3. Photos: J. Zens. STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY | 49

4 Loess-Palaeosol Sequences at the Northern European Loess Belt in Germany: Distribution, Geomorphology and Stratigraphy

Frank Lehmkuhl a *, Joerg Zens a, Lydia Krauß a, Philipp Schulte a, Holger Kels a a Department of Geography, RWTH Aachen University, Templergraben 55, 52056 Aachen

* corresponding author: Lehmkuhl, Frank – [email protected]

Abstract

Pleistocene loess and loess derivates are distributed along the mountain front of the Central European Mountain Belt in northern and Central Germany. Examples from two regions, the Lower Rhine Embayment (LRE) and the northern foreland of the Harz Mountains (FHM) show that the distribution of loess and the development of loess-palaeosol sequences (LPS) are controlled by relief, climate, tectonics, the distance to large river systems, the distance to the Scandinavian ice sheet and the distance to the shelf of the North Sea. In the oceanic LRE higher humidity enhanced the periglacial processes which increased erosion, but also led to preservation in accumulative positions. In contrast, in the more continental FHM the sediments were affected by less intensive periglacial processes and no solifluction can be detected. New loess distribution maps are presented for both key areas, and key sections, especially for the last glacial cycle, are compared and summarized. Both study regions are located in the west – east trending loess belt north of the Central European Mountain belt (in front of the Rhenish Shield = Ardennes-Eifel and Harz Mountains). Finally, a synthesis of typical sediment sequences for both regions is given as an example of palaeoenvironmental (landscape) development in northern Central Europe.

Published 2016 in Quaternary Science Reviews Volume 153, 11-30.

4.1 Introduction Loess is one of the most extensively distributed Pleistocene deposits in Central Europe. It is widely spread along the European loess belt, the surroundings of the large river systems, and the sedimentary basins of low mountain ranges (Fig. 18). The thickness varies between decimetres to several tens of meters depending on the distance to the source area and the geomorphological setting. Due to wide distribution, loess-palaeosol-sequences (LPS) are the

50 | STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY

most intensively and extensively studied terrestrial archives used for the reconstruction of environmental and climatic changes of the Last Glaciation(s) in Central Europe.

The early stages of detailed loess-palaeosol research were focused on the development of individual stratigraphic schemes for every sub region based on pedological and sedimentological properties (e.g., Remy, 1960; Paas, 1962, 1968a, 1968b; Lieberoth, 1963; Schönhals et al., 1964; Rohdenburg and Meyer, 1966; Brunnacker, 1967; Semmel, 1968; Fink et al., 1977; Schirmer, 2000). The early work produced a large number of published loess sections. Some of these localities were later reinvestigated with luminescence dating to establish a chronological framework for phases of loess accumulation and soil development (e.g., Frechen, 1992, 1994, 1999; Zöller, 1995; Lang et al., 2003; Bibus et al., 2007; Frechen and Schirmer, 2011).

More recently, loess research has been focused on the impact of rapid climate oscillations on European continental environments by comparing biological, geochemical and sedimentological proxy data from LPS with variations in Greenland ice core data (e.g., Rousseau et al., 2002; 2007; 2013; Antoine et al., 2009; 2013; Moine, 2014; Schirmer, 2000, 2016). Such global variations are supposed to have caused the dispersal of anatomically modern humans from Africa and the migration into Europe ca. 40,000 years ago (e.g., Sitlivy et al., 2012; Schmidt et al., 2013; Nigst et al., 2014), as well as their probable absence during the Last Glacial Maximum (e.g., Uthmeier, 2006; Händel et al., 2009; Holzkämper and Maier, 2012a, b; Uthmeier et al., 2011; Holzkämper and Koch, 2014; Holzkämper, 2013; Moine, 2014), which is still in discussion (cf. Kels and Schirmer, 2010).

The potential and resolution of a LPS as an archive of palaeoenvironmental reconstruction is dependent on the topography (aspect, slope, and elevation), the distance to a source area and the (palaeo) climatic conditions. Several studies have shown that sedimentary traps such as dry valleys and tectonic depressions, or special morphological situations such as loess gredas (e.g., Antoine et al., 2001, 2009; Frechen et al., 2001), watershed positions (e.g., Fischer, 2010) and slope toes (e.g., Reinecke, 2006) provide favourable positions for high resolution LPS. However, the large number of studied loess sections have shown that the properties and preservation of units can vary even on very small scales like slope topo-sequences (e.g., Brunnacker et al., 1978; Reinecke, 2006). Therefore, it is essential to take both the recent topography and the palaeotopography into account to understand the interplay of accumulation, soil formation and relocation processes, controlled by different climatic conditions. As a result, even correlating LPS with neighbouring sections is often difficult if not impossible and thus the reconstruction of regional palaeoenvironment remains challenging. STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY | 51

Fig. 18: Distribution of loess and loess derivates according to Haase et al. (2007), modified with data from Zagwijn and van Staalduinen (1975) and Haesaerts et al. (2011a) for the Netherlands and Belgium. The maximum extent of the Weichselian and Würmian Glaciation is plotted according to Ehlers et al. (2004, 2011). The red star is the famous Nussloch LPS. Regions: (1) Northern Central European loess belt, sub regions: (1a) Lower Rhine Embayment (= LRE, box = Fig. 22); (1b) southern part of Westphalia, (1c) southern parts of Lower Saxony, (1d) Saxony- Anhalt including northern foreland of the Harz Mountains (= FHM, box = Fig. 24), (1e) Basin in Thuringia, 1f: Saxony. (2) Loess in the Upper Rhine graben. (3) Basins in the German Uplands, (3a) Lower Saxony and Hesse, (3b) Franconia, (3c) Kraichgau and Neckar catchment between Heilbronn and Stuttgart (4) Danube region, mainly SE part of Bavaria. T1, T2 and T3 show the position of transects displayed Fig. 21, Fig. 23 and Fig. 25.

52 | STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY

Besides local studies, upscaling towards a regional and supra-regional scale and comparison between different areas is important for understanding larger patterns as discussed by Schlummer et al. (2014). The Lower Rhine Embayment (LRE) and the foreland of the Harz Mountains (FHM) are two subareas of the northern European loess belt situated between the low mountain range and the Scandinavian Ice Sheet. They show general differences in geomorphological setting and modern climate conditions. The LRE is marked by a comparably flat topography interrupted by flat valleys and a few geological horst structures (e.g., Ville, Jackerather Horst). The flat topography gradually gives way to the surrounding low mountain range and the German lowlands. The climate is humid, affected by the oceanic influence of the Atlantic meridional overturning circulation. In contrast, the recent climate of the FHM is more continental due to the rain shadow effect of the Harz Mountains (see Fig. 19). The topography is undulating with higher relief energy and a thinner loess cover.

Geographically, both areas are distinguishable by precipitation differences. The LRE is marked by the oceanic influence of the Atlantic Ocean. The annual precipitation varies between 500 and 600 mm. In contrast, the FHM is characterized by a more continental climate strengthened by rain-shadow effects of the Harz Mountains, receiving annual precipitation amounts between 400 and 500 mm (Fig. 19). Those variations in precipitation result in different recent soils. In the LRE, most soils developed on loess are luvisols. chernozems are the typical soil type in the continental areas of the FHM and the interior of Bohemia, while the flood plains are dominated by fluvisols. On more intensively used agricultural land anthrosols and colluvial soils (colluvisols) occur. Due to the high soil fertility of the loess covered areas, all soils in these regions are predominantly used for agricultural purposes (LAGB, 2006; BGR, 2007; Zech et al., 2013).

Both the LRE and the FHM were already the subject of regional studies in the past. An overview of loess research in the LRE is given by Henze (1998), Kels (2007) and Fischer (2010). The general stratigraphic scheme was recently presented by Schimer (2016, and reference therein). It is mainly based on pedostratigraphy and only a few studies have provided numerical ages to validate the suggested chronology (e.g., Frechen, 1992; Henze, 1998; Fischer, 2010; Frechen and Schirmer, 2011; Fischer et al., 2012, Klasen et al., 2015a). The scheme is a composite of many studied LPS from the LRE but also from the Upper Middle Rhine Graben. A composition was necessary due to the many erosional unconformities that occur mainly in the vast flat plains of the LRE. For instance, the Middle Pleniglacial and the first half of the Upper Pleniglacial (see Fig. 26) are nearly completely missing in the entire area. Therefore, LPS from the transition zone of the vast plains towards the low mountain range (e.g., Düsseldorf-Grafenberg, Fig. 22, No. 18) and the Upper Middle Rhine Valley (e.g., Remagen- Schwalbenberg, Fig. 22, No. 15) were used to fill these stratigraphic gaps. The FHM were intensively studied by Feldmann (1996, 2002) and Reinecke (2006). Reinecke (2006) integrated STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY | 53 the new findings from the Middle Pleniglacial into the stratigraphic scheme of Lower Saxony and Northern Hesse by Meyer and Rohdenburg (1982).

Fig. 19: Modern annual precipitation (left, data adapted from Diercke Weltatlas, 2008) and dominant modern soils on loess (right, according to Scheffer and Schachtschabel, 1989) in Germany. The rectangles show the study areas of LRE and FHM (Fig. 22 and Fig. 24).

The differences between the LRE and FHM offer the possibility to compare the complex interplay of climate, geomorphology and periglacial processes controlling accumulation, preservation and erosion of LPS. Therefore, we present detailed maps and cross-sections to visualize the spatial distribution and arrangement of loess. The main focus lies on two sub- regions: the oceanic influenced LRE and the more continental affected FHM. For both areas, the stratigraphic models are presented and simplified in a general scheme. Typical LPS are presented as examples for palaeoenvironmental (landscape) development in northern Central Europe controlled by different climatic conditions and geomorphological settings.

4.2 Loess and geomorphologic setting Several attempts have been made to define the term loess and its characteristics. Unfortunately, no generally accepted definition exists at this point, resulting in various uses of the term loess and loess like sediments (see, e.g., Pécsi and Richter, 1996; Smalley et al.,

54 | STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY

2011; Sprafke and Obreht, 2015). Here, loess is defined as an aeolian, homogeneous, predominately silt-sized (20-63 µm), loose sediment where particles are weakly cemented by calcium carbonate. Since loess is a relatively loose material, the topography, including vegetation cover, plays a major role in its deposition, preservation and thus distribution on the Earth’s surface (Thome, 1998).

According to Pye (1995), four fundamental requirements are necessary for the formation of loess: a dust source, adequate wind energy to transport the dust, an accumulation area, and a sufficient amount of time (Fig. 20). This scheme from semi-arid and arid regions can be likened to the situation in Central Europe, particularly during the Upper Pleniglacial (UPG). Loess is mainly derived from sediments blown out from the formerly dried out shelves of the Channel and North Sea (cf. Smykatz-Kloss, 2003; Antoine et al., 2009), as well as the deflated material from the braided-river systems and the glaciofluvial outwash plains in front of the continental ice sheets (Smalley et al., 2009).

During sea-level minima, deflatable material from the exposed shelfs was mobilized and transported by westerly winds, particularly along west to east running storm tracks (Antoine et al., 2009). According to dust flux modelling, south-western and north-western winds are responsible for major dust input to Central Europe during seasons of reduced vegetation cover (Sima et al., 2009). Due to strong tide variations, different grain sizes are produced in modern marine sediments and in all probability also during the last glacial cycle. The sediments were primarily deposited on the leeside of topographic barriers mainly exposed to east and north- east (e.g., Antoine et al., 2003; Fig. 20c). Shallow marine minerals (e.g., glauconite, palygorskite) and remnants of foraminifera were found within loess from Northern France and the Pleiser Hügelland (northern middle Rhine Valley; Smykatz-Kloss, 2003). The amount and grain size of minerals and preservation of foraminifera decrease from west to east indicating long-term transport with abrasion and/or frequent reworking along a sediment cascade of traps from Northern France towards the LRE. However, the exposed shelfs mainly act as a temporary long-distance dust source that is only active when exposed and sufficient wind energy prevails.

In contrast, braided-river systems provided a huge amount of deflatable material of different grain sizes derived from glacial meltwater. The transport occurred mainly during spring to early summer. The deposition area was influenced by strong periglacial conditions during and after the deposition. Large parts of the formerly submerged and barren floodplains were exposed to wind when the braided rivers dried out. The broad spectrum of grain sizes produced by glacial grinding was highly susceptible to winnowing and allows for short-, medium- and long-distance transport (Fig. 20). STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY | 55

Fig. 20: Schematic models showing three conditions under which loess deposits may form (modified according to Pye, 1995): (A) formation of distal loess on vegetated material accompanied by formation of aeolian sand proximal to the sediment source; (B) formation of loess which is joined to proximal sand dunes and sand sheets by a transitional sandy loess zone; (C) accumulation of loess beyond or against a topographic barrier.

Once entrained by wind, particles were deposited downwind and sorted according to their grain size from sand toward loess with relation to wind speed, which resulted in a regional distribution of loessic grain sizes (Fig. 18, Fig. 22 and Fig. 24). Fig. 20 shows the different geomorphic settings adapted from a semi-arid region to situations in Central Europe: (A) formation of distal loess on vegetated material accompanied by the formation of aeolian sand proximal to the sediment source e.g., for part of the northern European loess belt close to the ice margins where loess is distributed further south due to missing vegetation; (B) formation of loess which is joined to proximal sand dunes and sand sheets by a transitional sandy loess zone - this occurs east of large river systems; (C) accumulation of loess beyond or against a topographic barrier like the low mountain range.

The degree of accumulation and preservation of loess and palaeosols depends on the interplay of topography (slope, aspect and curvature), climate (temperature, wind strength and direction) and sediment / soil properties (e.g., grain size, calcification, and decalcification) under a certain vegetation cover. For instance, higher loess accumulation rates were observed in depressions and lee sites of higher elevations according to the prevailing wind direction

56 | STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY

(cf. Antoine et al., 2003). Very often asymmetric (periglacial) valleys strengthened this process. Such dependencies were observed in the FHM by Reinecke (2006). He concluded that on slopes with a south-eastern aspect higher loess accumulation occurs by intensive solar insolation which promoted more dense vegetation cover. In addition, he assumed prevailing wind directions from the north and north-east.

Erosional unconformities are typical features of Central European LPS, making stratigraphy and correlations challenging. In periglacial environments, slope wash in combination with nivation (snow accumulation and ablation) and gelifluctions occurs if the moisture supply is sufficient (French, 2007). Relocation processes begin with a slope angle of 2° (cf. Washburn, 1979; French, 2007) and can be linear or extensive depending on the curvature. Deflation mainly depends on wind speed and surface roughness (vegetation cover and particle size). Clay contents of more than 20 % and cementation processes hamper deflation (Pye, 1995). Both types of erosional processes are difficult to differentiate in the field if relocated deposits and sedimentary structures are not preserved. Consequently, if the origin can be defined, it provides very useful information about palaeoclimate and environment. However, due to changes of climate and environmental conditions over time, the current topography is not necessarily the correct analog to former relief and may alter the understanding and interpretation of past accumulation and erosional processes. Landscapes developed on loose sediments could especially differ from past topographies. For instance, the recent flat topography of the LRE is the results of an extensive erosion event (the so called Eben unconformity, cf. chapter 4.1) and the following accumulation of loess, which covers the landscape equally like a veneer (Henze, 1998; Meijs, 2002; Antoine et al., 2003). The huge exposed walls of open-cast lignite mining show that the former landscape was more undulating than today (especially before the beginning of soil erosion and colluviation due to agriculture since the Neolithic), emphasizing the importance of larger exposures during interpretation (cf. Henze, 1998; Kels, 2007, Lehmkuhl et al., 2015).

Evaluating published studies, high-resolution LPS are connected to specific geomorphological settings, as revealed before. Loess gredas such as Nussloch (see Fig. 18; Antoine et al., 2001; 2009; Bibus et al., 2007; Gocke et al., 2014) or Harmignies (e.g., Frechen et al., 2001) are some of the best-resolution LPS due to the high and relatively constant loess accumulation. LPS on slopes can also offer good-resolution records, but demand correct interpretation of unit stratigraphy and formative processes. Several studies emphasize the difficulties in distinguishing between in-situ soils and relocated soil sediments (Reinecke, 2006; Schirmer, 2010; Fischer et al., 2012; Klasen et al., 2015a; Schulte et al., 2016). However, depending on slope position, relocated sediments can also protect underlying units from erosion, especially at foot slopes and depressions. Additionally, as a result of limited slope erosion, loess is preserved on watershed positions and therefore can also act as high- resolution LPS (cf. Fischer, 2010). LPS on plateau-like positions are much more densely stratified and provide a lower resolution for reconstructing palaeoenvironmental dynamics. STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY | 57

In contrast to watershed postions, plateau-like settings are not favourable locations for loess accumulation if a vegetative cover is missing (cf. Fig. 20). The impact of different processes on LPS in relation to the relief (A: Plateau, B: Slope, C: Slope toe, and D: Depression) are shown in Table S4-1_Tab. 1.

4.3 Loess distribution and regional setting Maps providing the distribution of loess and other aeolian sediments for the entirety of Europe were first presented by Grahmann (1932) and later by Fink et al. (1977). The most recent compilation by Haase et al. (2007) has been widely used in loess research. This map is mainly based on (local) geological maps done by researchers from different countries. In general, the mapping of loess and loess derivates in Germany started at the end of the 19th century by the different geological surveys (mainly by the Prussians; Wagenbreth, 2015). However, only loess sediments exceeding two meters of thickness were mapped in geological maps, causing gaps that can sometimes be filled by using soil maps and other sources. In general, the construction of such maps incorporates geographical, geological and pedological datasets from different countries or geological surveys, each employing their own set of definitions. Many of the maps presenting the distribution of loess and loess derivates in Europe display inconsistencies such as displacements, shifts, or even abrupt delimitations in loess distribution across national borders or even between different maps within one country. In fact, if geoscientific data from different regions or countries are combined, national borders in many medium- and large-scale thematic datasets appear as artificial breaks (cf. Nilson et al., 2007 and references therein). Such artificial breaks result from the need to simplify geodata sets from different countries or even different surveys within one country.

The loess distribution map of Haase et al. (2007) for all of Europe is of limited use for a more detailed regional consideration. For example, in the LRE the distribution of loess derivates according to Haase et al. (2007) is not complete since there is no loess mapped at the borders and within the Netherlands and Belgium, which were previously mapped by Paepe and Vanhoome, (1967), Zagwijn and Staalduinen (1975) and Haesaerts et al. (2011a).

For this study we produced an overview map (Fig. 18) and two more detailed maps of aeolian sediments for the study areas. The map of the LRE is based on the Geological Maps of North Rhine-Westphalia with a scale of 1:100,000 (Fig. 22, Geological Survey of North Rhine- Westphalia, 2013) and 1:200,000 (Federal Institute for Geosciences and Natural Resources, 1984/2002b; 2002). The map of the FHM was derived from several geological overview maps with a scale of 1:200,000 (Fig. 24, Federal Institute for Geosciences and Natural Resources, 1974/2002, 1984/2002a, 1986/2002, 1998). Cross sections through the investigation areas are shown in a simplification of the general spatial arrangement of near-surface Quaternary sediments (Fig. 21, Fig. 23 and Fig. 25).

58 | STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY

4.3.1 Distribution of loess in Germany In Germany loess is distributed in several main regions (Fig. 18): (1) the northern Central European loess belt, south of the Weichselian ice sheet in the North and in front of the German uplands in the South (e.g., Rhenish shield, Harz Mountains, Ore Mountains (Erzgebirge); see Fig. 18); (2) the Upper Rhine Valley (Upper Rhine Graben); (3) the basins of the mountain areas in Central and SW Germany; and (4) along the Danube River, mainly in the south-eastern part of Bavaria. These regions can be divided into several sub-regions (see Fig. 18). For example, the northern loess belt includes six main sub-regions: (1a) Lower Rhine Embayment (LRE); (1b) loess in the southern part of Westphalia (Münsterländer Bucht, Soester Börde); (1c) southern parts of Lower Saxony including Hildesheimer Börde; (1d) Saxony-Anhalt including the northern foreland of the Harz Mountains (FHM); (1e) loess in the Basin of Thuringia; and (1f) loess in Saxony.

The thickness of loess varies between several meters (locally more than 10 m and up to more than 20 m in the extreme) and less than one meter (e.g., Schirmer, 2002a 2012; Haesaerts et al., 2016). The distribution is restricted to areas below 200 m asl along the northern loess belt (region No. 1 in Fig. 18) and between 300 to 500 m asl within the low mountain range (see Fig. 21 and region No. 3c in Fig. 18). At higher elevations loess is mixed with periglacial cover beds resulting in the upper cover bed (Hauptlage), as well as the middle periglacial cover bed or the intermediate layer (Mittellage) in restricted areas. Lower (older) periglacial cover beds (Basislage) did not contain loess (Semmel and Terhorst, 2010).

Fig. 21: North-south section along the Rhine River (right bank, looking from the west) showing the distribution of sand and loess along the Rhine and towards the mountains east of the river up to 400 m asl. In higher elevations periglacial cover beds and glaciers in the Black Forest occurred during glacial cycles (based on data from Fig. 18 and Fig. 22).

The comparison of the spatial arrangement of loess and the resolution of LPS in both areas show some similarities and differences. A northern border of loess occurs gradually, changing STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY | 59 the sedimentary environment towards aeolian and cover sands in both areas (e.g., Poser, 1948; Gehrt, 1994).

4.3.2 Lower Rhine Embayment (LRE) The LRE is part of the western European rift system (Ahorner, 1962; Schirmer, 1990; 2003). It is a tectonic fracture zone dominated by relative subsidence with rift valleys, horsts and half-horst structures; it is surrounded by the Rhenish shield (Eifel Mountains in the south and Bergisches Land to the East with elevations higher than 800 m asl; Boenigk and Frechen, 2006). To the north, the LRE opens towards the North German Plain and Westphalian lowlands. The general elevation varies from ~160 m asl in the South to less than 40 m asl in the north. It turns gradually into the surrounding low mountain range. The topography is flat and interrupted by fluvial valleys and horst structures like the Ville and Jackerather Horst with more than 200 m asl (Boenigk and Frechen, 2006).The annual precipitation varies between 800 mm in the western part to 650 mm in the south-eastern area in the rain shadow of the Eifel Mountains.

NW to SE striking normal faults dominate and divided the LRE into several blocks with different rates of vertical movement and lateral tilting (Ahorner, 1962). The highest subsidence occurs in the eastern part of the major geological clods (Ahorner, 1962; Klostermann, 1992). This promotes high sedimentation rates and a good preservation of Pleistocene deposits especially along the major faults of the Rurrand and Erftcrack system and along numerous subordinated faults. The Pleistocene deposits mainly consist of glaciofluvial, fluvial and aeolian sediments overlying tertiary sands (Klostermann, 1992). Glacial deposits are subordinate and only occur in the North of the southern boundary of the maximum extent of the Scandinavian ice shield during the Saalian glacial stage (Fig. 22). The spatial distribution of aeolian sediments is shown in Fig. 22. The dominant aeolian sediment is loess, which is widely distributed over the entire LRE with thicknesses of more than 2 m. The thickest loess deposits can be found in subsidence areas especially on the subsided parts of the major blocks (Kels, 2007). In general, the thickness decreases towards the low mountains and from south-east to north-west (despite sedimentary traps), where it merges with sandy loess, sandy cover sheets and dune sands along the Meuse and Rhine Rivers (Fig. 23). Towards the North, sandy deposits are also present at the eastern side of the Holocene Rhine River flood plain, where a transition into a thin loess cover at the steeper slopes of the uplands occurs. Fluvial terraces formed during the Weichselian glaciation (lower terraces = Niederterrassen) have only limited preservation of LPS or no loess cover at all. Fig. 21 provides a cross-section along the Rhine River, from Düsseldorf in the North towards Basel in the South. This general pattern is in accordance with model B of Fig. 20.

60 | STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY

Fig. 22: Loess distribution in the Lower Rhine Embayment. The numbers indicate key sections mentioned in the text or supplement. Map based on the Geological maps 1:100,000 (Geological Survey of North Rhine-Westphalia, 2013), and the Geological maps 1:200,000 (Federal Institute for Geosciences and Natural Resources, 1984/2002b; 2002). The extent of the opencast lignite mining area is derived from the Geological maps and therefore older than 1990. The maximum extent of the Saalian glaciation was constructed according to Ehlers et al. (2004, 2011). STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY | 61

Fig. 23: Generalized West-East profile from the Meuse River towards the Rhine River and the mountain area of the Bergisches Land (based on the geological data from Fig. 22). The position of the cross-section is shown in Fig. 18 (T2).

4.3.3 Northern foreland of the Harz Mountains (FHM) The northern foreland of the Harz Mountains is between the flat North German Plain and the Harz Mountains. The Harz Mountains achieve elevations of between 600 and 1,300 m asl, whereas Mesozoic tectonic saddles in the northern Harz foreland are between 300 and 400 m high. Today, the FHM is at the transition between the humid (oceanic) north-western German lowlands, with annual precipitation above 650 mm, and the dryer and more continental areas of central and eastern Germany where annual precipitation amounts can fall below 500 mm (Fig. 19). The north-eastern to south-eastern Harz forelands are characterized by lee-effects caused by the Harz Mountains, resulting in decreased precipitation in contrast to the Harz Mountains themselves and their western and southern foreland. They are a part of the so- called central German arid region. Since the lee-effect continuously decreases towards the east, the amount of precipitation increases again eastward (Haase et al., 1970; Reinecke, 2006; Krauß et al., 2013).

Geologically, the FHM belongs to the Subhercynian Basin, which is bordered by uplifted Palaeozoic basement blocks in the north-east, south-east and south. The basin is open to the north-west and covered by Mesozoic and Cenozoic sediments. The originally horizontally- bedded Mesozoic layers are arched-up anticlinally at several locations due to block faulting and salt tectonics (Germanotype tectonics). The basins between those saddles are covered by various Cretaceous and few Cenozoic sediments (Haase et al., 1970; Reinecke, 2006). Overlying unconsolidated Pleistocene deposits show varying thicknesses. These deposits mainly consist of fluvial terraces and glacial deposits of the penultimate glaciation (early Saalian) and Weichselian aeolian sediments. The FHM was mostly covered by the Scandinavian Ice Sheet during the middle Pleistocene (Elsterian and Saalian) glaciations. The early Saalian glaciation reached the Harz Mountains up to about 300 m asl (Bombien, 1987; Reinecke, 2006). During the Warthe Stadial and the Weichselian the ice sheet was situated

62 | STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY

just 50 to 150 km further north and the FHM transferred into a periglacial region (Reinecke, 2006). Braided rivers stemming from local glaciers in the highest parts of the Harz Mountains distributed large amounts of gravel in the valleys while loess accumulated on the older, higher land surfaces. Due to the presence of ice there are only thin or absent layers of aeolian sediments deposited in elevated areas.

The Weichselian loess cover of the northern and eastern Harz foreland surrounds the Harz Mountains in a 40 to 50 km wide belt (Fig. 24). Loess and loess derivates are most common at elevations below 250 m, but some patches reach elevations up to 400 and 500 m (Haase et al., 1970; Reinecke, 2006). Despite profiles in special settings, such as subrosion depressions, the loess cover rarely reaches more than 2.5 m in thickness (Haase et al., 1970; Reinecke, 2006; Krauß et al., 2016).

The loess does not directly contact to the Harz Mountains in the south. This is caused by periglacial alluvial fans, even from small rivers, as well as by the lower terraces of the different rivers sourced from the Harz Mountains which hamper loess accumulation (Bode et al., 2003). In addition, the Mesozoic and Cenozoic anticlinal arched-up saddles are also free of loess (see Fig. 25). Further, there is a clear end of the loess distribution towards the north and north- east. Gehrt (1994) described the area of the border as a result of several phases of aeolian accumulation with material getting increasingly sandier with decreasing age. Fig. 25 provides a northeast-southwest profile from the ice margin of the Saalian Warthe stadial towards the Harz Mountains, which was also the prevailing direction of katabatic winds from the ice sheet during the Last Glacial Maximum (LGM). The figure shows the distribution of sandier material and the absence of loess 10-15 km in front of the ice margin or mountain range in accordance with the model in Fig. 20 A. In summary a 20 to 40 km wide, thin loess belt exists in the area. The loess records only contain material from the last glacial cycle due to the cover provided by the Saalian ice sheet. STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY | 63

Fig. 24: Loess distribution in the northern foreland of the Harz Mountains. The numbers indicate key sections mentioned in the text or supplement. Map based on the Geological map 1:200,000 provided by the Federal Institute for Geosciences and Natural Resources (1974/2002; 1984/2002a; 1986/2002; 1998). The ice margins are according to Ehlers et al. (2004, 2011).

Fig. 25: NE-SW-Profile from the ice margin of the Saalian Warthe stadial towards the Harz Mountains with the local glaciation and including ridges of Mesozoic bedrock in the foreland (e.g. km 70 to 75) (based on the geological data from Fig. 24). The position of the cross-section is shown in Fig. 18 (T3).

64 | STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY

4.4 Loess stratigraphy During the 20th and beginning 21st century several loess stratigraphies of the last glacial cycle were published for the different sub-regions in Central Europe (e.g., Remy, 1960; Schönhals et al., 1964; Rohdenburg and Meyer, 1966; Brunnacker, 1967; Meyer and Rohdenburg, 1982; Henze, 1998; Zöller and Semmel, 2001; Reinecke, 2006; Schirmer, 2016). The aim was to characterize the general climatic and environmental alternations on a more regional scale with a focus on palaeopedology. This makes sense against the background of heterogeneous geomorphology and climate gradients in Central Europe (cf. Fig. 18 and Fig. 19). The fluctuating boundaries of continuous and discontinuous permafrost during glacial periods additionally influence the regional variability of soils and periglacial processes (cf. Vandenberghe et al., 2012). Therefore, it is not necessarily the case that every unit found at a specific section or identified on a regional scale can be recovered in other areas, too. Only a few LPS are supposed to cover the entire succession of the last glacial cycle, such as Nussloch (Antoine et al., 2001, 2009), Wiesbaden-Gräselberg or Wiesbaden Hainerberg (Semmel, 1968). Some LPS seem to reflect specific phases in much more detail. For example, in most generalised stratigraphies the Middle Pleniglacial contains two palaeosols addressed as calcic or arctic cambisols (cf. Schönhals et al., 1964; Rohdenburg and Meyer, 1966; Semmel, 1968; Antoine et al., 2001; Bibus, 2002). However, from several single sections up to eight palaeosols were documented where the differentiation between an autochthonous soil and redeposited soil sediment is not ensured (Reinecke, 2006; Schirmer, 2012). Comparable observations were made for the Upper Pleniglacial where five to six cryosols are mentioned in the stratigraphic schemes (so-called Erbenheim Soils sensu Schönhals et al., 1964). In contrast, the Nussloch LPS contains up to eight cryosols (Antoine et al., 2009). Sometimes the findings from such high resolution sections were considered in the general stratigraphic scheme (e.g., Reinecke, 2006; Schirmer, 2016), or at times they were mentioned as special situations and deemed outliers (Schönhals et al., 1964; Semmel, 1968). However, stratigraphic models are always a composite of several loess sections and hence influenced by the local geomorphology and climatic conditions on a regional to large scale. The decision for or against the integration of units is always a matter of debate.

The discrepancies between a ‘normal case’ and ‘special settings’ (such as Nussloch and Schwalbenberg II, S4-1_Fig. 15) highlight the challenge of constructing, combining and comparing stratigraphies against the background of erosion and different accumulation rates. Several correlative attempts were made in the past mainly based on pedostratigraphy (e.g., Schönhals et al., 1964; Semmel, 1968; Schirmer, 2000). Without additional age information by direct radiometric dating such approaches strongly depend on the author’s regional and supraregional knowledge concerning stratigraphy, the properties of the major units, and differences between various palaeosols studied at numerous differing sections. Several direct dating studies conducted during the last decades push the chronological knowledge forward. Systematic thermoluminescence dating studies of several LPS from Central Europe were STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY | 65 summarised by Zöller (1995) and transferred into a general stratigraphic and geochronological framework (Zöller and Semmel, 2001). Furthermore, additional studies were conducted which improved the chronological knowledge by direct dating (e.g., Frechen, 1999; Lang et al., 2003; Kadereit et al., 2013; Meszner et al., 2013) or correlation to independent time scales and proxies such as Greenland ice core data (e.g., Schirmer, 2000, 2016; Rousseau et al., 2007; Antoine et al., 2009, 2013; Kadereit et al., 2013; Haesaerts et al., 2016). Due to uncertainties in the different dating techniques, unconformities and short time climatic oscillations such as Dansgaard- Oeschger cycles are difficult to determine precisely. However, studies have shown that promising results can be achieved (cf. Antoine et al., 2009; 2013) especially if marker beds such as tephra layers were used as chronostratigraphic markers.

Despite advances in stratigraphy and geochronology, there is still no systematic comparison or universal scheme for the last glacial cycle in Central Europe, though the major units are known and the chronological position is roughly determined. It can be argued that a universal stratigraphy cannot represent the heterogeneous geomorphological and climatic conditions that resulted in the spatial diversity of loess units. However, several studies have shown that major units (palaeosols) exist that are comparable and assumed to be contemporaneous over many hundreds of km, such as the chernozem-like steppe soils of the Early Glacial (Mosbacher Humus Zone: Fig. 26, Semmel, 1968; Bibus, 2002; Antoine et al., 2013; Haesaerts et al., 2016). Such units have the potential to act as a stratigraphic and chronologic marker for a more universal notation, which can also be used in local stratigraphies. The scheme of Schönhals et al. (1964) for the last glaciation bolstered with further advances (e.g., Bibus, 2002) is currently the most frequently used notation. Therefore, we introduced a simplified notation to correlate the regional stratigraphies of the LRE and FHM and avoid confusion by using different local names (Fig. 26). Here, we interpret the major units as time-synchronous climate and environmental phases which can regionally form different soil/sediment properties. The reference timescale is provided by the GRIP ice core chronology and GICC05modelext timescale (Rasmussen et al., 2014; Seierstad et al., 2014) as it was frequently used in recent loess studies (e.g., Antonine et al., 2013; Kadereit et al., 2013; Schirmer, 2016). Based on published luminescence dating from several loess sections (for references see below), a correlation to groups of Greenland interstadials is proposed. These groups are named and modified according to the pedostratigraphic notation of Antoine et al. (2009, 2013) as Eemian, Early Glacial, Lower-, Middle-, Upper Pleniglacial (Phase A and B) and Late Glacial. The separation of the Upper Pleniglacial into Phase A and B is argued for due to an abrupt change from niveo-aeolian to homogenous loess (cover loess) deposition indicating an important climatic turnover around the regional LGM of Europe. The oxygen isotopic stages (OIS) are mentioned as an additional large scale climatic orientation (without temporal demarcation). Some major statements from several studies are summarized for every period. In the following we first describe the general stratigraphy and focus on the sedimentary successions in the LRE and FHM.

66 | STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY

Fig. 26: Simplification and comparison of the loess stratigraphy of the Lower Rhine Embayment (Schirmer, 2016) and a compiled stratigraphy of Northern Hesse/Lower Saxony and the FHM (Meyer and Rohdenburg, 1982; Reinecke, 2006) and their correlation to the GRIP oxygen isotopic notation and Ca2+ content, 60yr average (Rasmussen et al., 2014; Seierstad et al., 2014). The Eben Zone contains the Kesselt Layer, Belmen, Elfgen soils (cf. Schirmer, 2016).The data are a summary of several published studies. The age ranges are based on luminescence and radiocarbon data adapted from several studies (references in the text).

4.4.1 Stratigraphical and chronological framework of the last glacial cycle (1) Eemian Interglacial (Eem, OIS 5e): The Eemian Soil appears as a strongly decalcified luvisol with clay illuviation and often hydromorphic features. (e.g., Haesaerts et al., 1999; Haesaerts and Mestdagh, 2000; Kels, 2007; Schirmer, 2010, 2016; Meszner et al., 2013).

Dating: e.g., Lang et al., 2003; Kreutzer et al., 2012a; Fischer et al., 2012.

(2) Early Glacial (EG, OIS 5d-a, GI-25 – 19.2): The upper, middle and lower Mosbacher Humus Zone, are chernozem-like steppe soils of different intensity and one greyzem. They were often developed within a mixture of relocated sediments and homogenous loess. Between the pedogenesis of each unit, erosion and loess deposition occurred (e.g., Semmel, 1968; 1989; 1999; Haesaerts et al., 1999; Löscher and Zöller, 2001; Mania, 2003; Bibus et al., 2007; Kadereit et al., 2013; Meszner et al., 2013; Schirmer, 2016). The Early Glacial is associated STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY | 67 with a cold steppe environment with grasses during colder phases and an open boreal forest during warmer phases (e.g., van Huissteden and Kasse, 2001; Zech et al., 2012; Meszner et al., 2013). Palaeosols such as luvisols and chernozem-like soils were documented in favourable geomorphological settings in the LRE (Schirmer, 2010), in Lower Saxony (Rohdenburg and Meyer, 1966; Meyer and Rohdenburg, 1982) and the Neckar Basin (Bibus et al., 2008).

Dating: (e.g., Zöller et al., 1988; Frechen et al., 1995; Frechen and Preusser, 1996; Frechen, 1999; Haesaerts and Mestdagh, 2000, and references therein; Boenigk and Frechen, 2001; Van den Haute et al., 2003; Bibus et al., 2007; Schmidt et al., 2011b; Kreutzer et al., 2012a; Fischer et al., 2012).

(3) Lower Pleniglacial (LPG, OIS 4, GS-19.2 - 18): The Niedereschbach Zone is the result of a phase of intensive reworking of older soil material and sediments (unconformity with linear incision) with embedded loess layers redeposited as laminated colluvium (e.g., Rohdenburg and Meyer, 1966; Semmel, 1989; Bibus et al., 2008; Meszner et al., 2013). Post- sedimentary biological processes can occur (Semmel, 1989) and dissolve the laminated structure. The relocation phase is followed by homogenous loess accumulation. In the LRE, several cryosols were associated with the LPG, situated on top of the Niedereschbach Zone (Kels, 2007; Schirmer, 2016). For other regions, only one cryosol was observed in individual sections (e.g., FHM: Reinecke, 2006; Neckar Basin: Bibus, 2002; Nussloch: Antoine et al., 2001 and Löscher and Zöller, 2001). Due to the lack of dating from this soil formation, it is not included in the simplified stratigraphy.

Dating: (e.g., Zöller und Wagner, 1990; Frechen et al., 1995; Frechen, 1999; Schmidt et al., 2011b; Kreutzer et al., 2012a; Meszner et al., 2013).

(4) Middle Pleniglacial (MPG, OIS 3, GI-17.2 – GI-5.2): The Middle Pleniglacial Gräselberg, Böcking and Lohne Soils are described as calcic, arctic or brown cambisols of different intensities and colours followed by erosion (e.g., Semmel, 1968; Antoine et al., 2001; Bibus, 2002; Bibus et al., 2007; Kadereit et al., 2013; Meszner, et al., 2013). Often they are capped or entirely eroded, mostly due to strong erosion around the Middle to Upper Pleniglacial boundary (e.g., Meszner et al., 2013). To date, it is unclear if the Gräselberg and Böcking Soils belong to the same or different pedogenic phases. In sections with high sedimentation rates, such as the loess greda in Nussloch, up to three interstadial soils were observed. The LPS of Schwalbenberg II (S4-1_Fig. 15, Schirmer, 2012, 2016) and Ermsleben (Reinecke, 2006) may contain up to 6 and 8 soils, respectively, for which the distinction between soil sediments and autochthonous soil is still under discussion. However, due to this uncertainty and isolated occurrences only three soil formations were included in the stratigraphic model, as suggested by Bibus (2002). Frequently, only one soil is preserved (Lohne Soil) due to the observed

68 | STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY

erosion, which is often addressed as relocated soil sediment (e.g., Semmel, 1968). In contrast, sedimentation rates are thought to have been low for some sections, hence several cambisols developed into a single soil and are addressed solely as the Lohne Soil. Palaeoenvironmental data such as pollen (Sirocko et al., 2013, 2016), n-alkane (Zech et al., 2012) and isotopes of organic matter in loess (Hatté and Guiot, 2005) suggest a highly variable landscape during the MPG with tundra scrubland, spruce and gallery forests of different species compositions dictated by the intensity of the interstadials.

Dating: (e.g., Zöller et al., 1988; Zöller and Wagner, 1990; Frechen et al., 1995; Zöller, 1995; Radtke et al., 1998; Frechen, 1999; Hatté et al., 2001; Lang et al., 2003; Bibus et al., 2007; Rousseau et al., 2007; Frechen and Schirmer, 2012; Kadereit et al., 2013; Gocke et al., 2014)

(5) Upper Pleniglacial, Phase A (UPGa, OIS 2, GS-5.2 – GS-2.1): The Erbenheim Soils 0-3 (E-Soils) are cryosols of different intensity developed under permafrost degradation during short and weak interstadials; possibly connected to Dansgaard-Oeschger cycles (e.g., Antoine et al., 2009). The loess accumulation was generally high (Frechen et al., 2003; Seelos et al., 2009) and the loess is finely laminated and niveo-aeolian in nature (e.g., Henze, 1998; Schirmer, 2000; Antoine et al., 2009; Kadereit et al., 2013; Meszner et al., 2013). The environment is described as polar frost tundra without trees (Zech et al., 2012; Sirocko et al., 2013; 2016). In some regions, the Eltville and Rambach tephras are present as chronological marker beds (Pouclet and Juvinge, 2009). The Upper Pleniglacial ends with relocated sediments (called the Kesselt Layer in the LRE) of a very strong phase of erosion (Eben unconformity) that are restricted mainly to the LRE and Belgium (Schirmer, 2003). A comparable unconformity was reported from the FHM by Reinecke (2006) but without the redeposited sediments. In other areas, the demarcation is determined with the deposition of the substrate for the E4 Soil (Schirmer, 2016).

Dating: (e.g., Buschbeck et al., 1992; Frechen et al., 1995; Zöller, 1995; Radtke et al., 1998; Van den Haute et al., 1998; Preusser and Frechen, 1999; Hatté et al., 2001; Lang et al., 2003, Tissoux et al., 2010; Schmidt et al., 2011b; Kreutzer et al., 2012a; Meszner et al., 2013)

(6) Upper Pleniglacial, Phase B (UPGb, OIS 2, GI 2 to GS 1): The Erbenheim-Soils 4 and 5 (E-Soils) are cryosols, regosols and calcic cambisol of differing intensity. The E4 Soil (complex) is the most developed soil that formed during the Upper Pleniglacial and can be correlated to the GI-2. The E5 soil cannot be attributed to a warming signal in Greenland ice core data. The light-brownish Bölling-Alleröd soil is usually overprinted by the Holocene soil formation. Sometimes, it can be found preserved below the Laacher See Tephra (Ikinger, 1996; Schirmer, 2016). Loess deposition changed from niveo-aeolian to homogenous, primary loess without sedimentary structures (e.g., Henze, 1998). High sedimentation rates are STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY | 69 characteristic for the LRE. The climate is thought to have been more arid and colder than during the Upper Pleniglacial, phase A (Henze, 1998; Schirmer, 2000, 2003; Kels, 2007; Meszner, et al., 2013) and possibly connected to the Last Deglaciation (cf. Kadereit et al., 2013; Hughes et al., 2016). Pollen data from the Eifel maar cores suggest a polar desert existed until the beginning of the Bölling-Alleröd interstadial (Sirocko et al., 2016), with a possible last loess input that occurred after this interstadial (cf. Hilgers et al., 2001).

Dating: (e.g., Van den Haute et al., 1998; Kreutzer et al., 2012a; Meszner et al., 2013)

(7) Holocene (OIS 1): Surface soil formation and soil erosion beneath colluvial sediments and soils, especially at foot slope positions and in depressions (e.g., Protze, 2014).

4.4.2 Stratigraphical specifics and selected key sections from the Lower Rhine Embayment (LRE) LPS from very different sections play a crucial role in the LRE, because larger unconformities occurred at the EG/LPG, MPG/UPG and UPGa/UPGb transitions, especially in the flat plains where most of studied LPS are located. Because of the deeply incised discordances, MPG and UPGa sediments are rarely preserved. The palaeosols of the Eben Zone sensu Schirmer (2003) build the first solcomplex of the UPGb and are widely distributed in the LRE. To fill the gaps of the stratigraphic scheme, loess sections were included which are located on special geomorphological positions with high accumulation rates and favourable preservation characteristics such as Grafenberg (interfluve/watershed, Fig. 22, No. 18; Henze, 1998; Schulte et al., 2016) and Schwalbenberg II (slope, Fig. 22, No. 15; Schirmer, 2012, Klasen et al., 2015a). Both sections show well stratified records for the MPG and UPG. Mostly Schwalbenberg II was used to complete the Middle Pleniglacial sequence of the LRE (Schimer, 2016). However, it must be noted that this section is strictly speaking not located in the LRE as it is usually defined and may reflect different environmental and climatic conditions on a local scale under very special circumstances of preservation. Also, the UPGa sediments are limited to a few sites such as Lommersum, Grafenberg and Brühl (Fig. 22, No. 12) (Brunnacker et al., 1978; Henze, 1998; Kels, 2007) and are generally not present in the flat plains due to erosion.

Therefore, it is useful to know the conceptual basis on which a stratigraphic scheme was developed, especially if a single section will be interpreted and correlated. To visualize the ‘normal case’ in the flat plains, we choose four LPS from big outcrops such as the opencast lignite mining areas or clay pits (Fig. 27 a-d). Due to more intensive and detailed loess research since the 1950s, a large number of sections were published that document landscape development on larger scales and hence promote general statements for this area. In addition, further LPS shown in Fig. 22 are presented in the supplementary materials, S4-2_Tab.1 and S4-2_Tab.2.

70 | STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY

1. Garzweiler South is a 120 m wide and 14 m thick exposure in the open-lignite mine Garzweiler (Fig. 27 a see also Fig. 22 and S4-2_Tab.1, location 5). The section was described by Kels (2007) as wall 7 (supplementary 1 and 2). It shows a gentle slope position towards a palaeochannel where different LPS were preserved. Above the gravel of the Upper Terrace, pre-Eemian loess (>OIS 6) is accumulated. The upper part of this loess unit is the substrate for the formation of the Eemian soil (OIS 5e), followed by parts of the Mosbacher Humus Zone which are developed in early Weichselian loess. In Garzweiler most units of the Eemian and Early Glacial have been observed over an area of several hundred meters (documented, e.g., by Schirmer, 1999, 2000; Kels, 2007). Because of its individual composition with numerous palaeosols separated by thin loess, this solcomplex of Eemian and Early Glacial soils serves as a helpful unit for a first relative dating in the field. These units are only well preserved in slope positions with small gradients and at the edge of palaeochannels. Small gullies incised into the solcomplex are indicative of strong slope wash. The relocated deposits (Niedereschbach Zone) fill erosive channels as well as depressions. Within the following primary loess of the Lower Pleniglacial there are several cryosols of OIS 4 developed (Fig. 22 and S4-2_Tab.1, location 5; Kels, 2007). Apart from some relict soil fragments at the top of a filled palaeochannel, the Middle Pleniglacial (OIS 3) deposits were eroded by a further event called the Eben unconformity. The E4 Soil complex and the UPGb sediments are nearly completely preserved (Kels, 2007; Lehmkuhl et al., 2015).

2. The 12 m thick section, Elsbach Valley (Fig. 27 b; see Fig. 22 and S4-2_Tab.1, location 5), was situated in a valley head of the small creek Elsbach that drained towards the Erft and Rhine River system (Kels, 2007, wall 11). Numerous dry valleys close to the modern watershed between Rhine and Meuse are dissected into loess deposits. Therefore, it is an example of palaeochannels filled with relocated sediments. Saalian sediments (> OIS 6) cover the Upper Terrace with small remnants of the Eemian soil on top (OIS5e). Based on stratigraphic evaluation, it was eroded during the Lower Pleniglacial (OIS4) or Middle Pleniglacial (OIS3). The Middle Pleniglacial (OIS3) is completely missing and reflects the ‘normal case’ of the LRE. Phase B of the Upper Pleniglacial (OIS 2) is well preserved. The Eben unconformity eroded older sediments and followed the palaeochannel, which was refilled with Holocene colluvial sediments in the middle of the valley.

3. The section Erkelenz (brickyard Gillrath, Fig. 27 c; see Fig. 22 and S4-2_Tab.1, location 3) was first presented by Schirmer (2002c). The thickness is about twenty meters. This section shows the dependency of preservation of LPS on palaeo-depressions and channels, even for pre-Eemian sediments. In the youngest palaeochannel, the Eemian Soil (OIS 5e) and parts of Lower Pleniglacial palaeosols are preserved. Though the older loess is well preserved, the Weichselian loess is partly missing in the brickyard. Only the late Last Glacial loess is preserved as a thin cover. Older Weichselian deposits seem to be cut by the Eben unconformity. Some small sandy deposits within the uppermost layers of the section are an indication for the adjacency of Erkelenz to the sandy loess deposits north-west of this quarry. STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY | 71

4. The setting of the former brickyard Rheindahlen (detail in Fig. 27 d; see Fig. 22 and S4- 2_Tab.1, location 2) is missing the last glacial loess due to a strong erosion phase(s). The thickness of the setting is about nine meters. Though the pit “exhibits a very small window of the big Rhine-Meuse loess stacks”, it is one of the best outcrops showing the Erft Solcomplex (OIS 7) in detail (Schirmer, 2002 a, c). The section became famous because of several layers with Palaeolithic findings. Schirmer (2002b) provided strong arguments that they belong to OIS 7 and not to OIS 5 as suspected by Schmitz and Thissen (1997) and Thissen (2006). Remarkably, this section lacks Weichselian loess units (Schirmer, 2002 a, c). Even the characteristic Late Glacial units are missing. The Eemian Soil is directly below the present surface and followed by pre-Eemian sediments going back to the OIS 7. The causes behind the lack of these units are still a matter of debate.

Fig. 27 a-d: Selected and simplified loess sections from Lower Rhine Embayment. For locations see Fig. 22, further details in S4-2_Tab.1.

72 | STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY

4.4.3 Stratigraphical specifics and selected key sections from the northern foreland of the Harz Mountains (FHM) The stratigraphy of the FHM for the last glacial cycle was developed by Reinecke (2006) based on observations from 18 LPS. It is a composite of the stratigraphy from Rohdenburg and Meyer (1966) for the Upper Pleniglacial and the classification of soil clusters according to Schirmer (2000) for the Middle Pleniglacial and Early Glacial. New local names for the palaeosols in these clusters were established, deemed youngest to oldest: Ermsleben soil (7-1) and Hecklingen soil. Later on, an update was presented on the 55. Geographentag in Trier 2005 by Reinecke simplifying the Middle Pleniglacial soils to Ermsleben 1-3 Soils (Reinecke, oral communication 2007).

The local stratigraphy is a composite of three LPS (Fig. 28), which is mainly based on pedostratigraphy and additional infrared-stimulated luminescence dates (Reinecke, 2006). However, they are assumed to be systematically too young due to anomalous fading at, least for the section Hecklingen (Krauß et al., 2016). A composite was necessary because most LPS contained < 2.5 m cover loess of the UPGb above the underlying bedrock. Reinecke (2006) suggested that this was caused by the flat topography of those areas, which allows extensive slope wash during the more humid Phase UPGa (Fig. 26). Additionally, he assumed that a major unconformity occurred during or shortly after the UPGa/UPGb boundary, comparable to other loess areas in Central Europe (Reinecke, 2006). The E4 soil and UPGa sediments are partly missing. Therefore, areas with loess cover greater than 2.5 meters must be differentiated from those at or below this thickness. In the eastern FHM LPS with higher thicknesses and resolution are situated in settings with reduced erosion on slope positions due to differences in slope, aspect, curvature and less precipitation (Fig. 28).

1. The section Ermsleben (Fig. 28a; see Fig. 24 and S4-2_Tab.2, location 5) is situated at the western wall of the old sunken road “Hohlweg Konradsburg”. The thickness of the SW exposed section is about 11 m. It is located on a local flattening of the gently inclined slope (2°) with a concave vertical and convex horizontal curvature. This geomorphological setting provides favorable conditions for the accumulation and preservation of Middle Pleniglacial units. Seven different palaeosols were documented (Ermsleben 1-7) and some of the units could also be relocated soil sediment. The Ermsleben 1 - 3 unit is equal in stratigraphy to the Heckling soil. The erosion beyond the MPG/UPG unconformity seems to have reduced the amounts of the youngest sediments. It can be stated that during OIS 3 and 4 relatively stable phases of soil formation alternated with phases of higher geomorphologic activity with periglacial erosion and solifluction. The Upper Pleniglacial deposits in the Ermsleben section show a very low resolution and only contain UPGb loess without cryosol formations (Fig. 26).

2. The section Hecklingen, with a thickness of 11 m, is situated at the western margin of the village Heckingen in a former clay pit (Fig. 28b; see Fig. 24 and S4-2_Tab.2, location 6). It was first published by Reinecke (2006) and more recently reinvestigated by Krauß et al. (2016). STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY | 73

The section is situated at the upper part of a horizontally stretched and vertically convex slope inclined at an angle of 5° and exposed to the SW. The morphological setting seems to have promoted strong erosion processes during the Middle Pleniglacial as indicated by relocated soil sediments and equal luminescence ages between 6 and 9 meters depth (see Fig. 28). In addition, small gravels of up to several centimetres are imbedded in the upper part of the Middle Pleniglacial strengthening the assumption of strong erosion (Krauß et al., 2016). Therefore, correlating soil units to the general stratigraphy for the Heckling soil introduces strong uncertainties. The Upper Pleniglacial appears in a series of alternating loess beds and cryosols. The upper cryosol separates laminated and partially cryoturbated loess from pure loess of the last cover loess period. Downslope, the upper Pleniglacial cryosols grow together due to relocation processes.

3. The LPS Schadeleben is located on a flat inclined (0.5°) east facing upper slope with a convex formed (horizontal and vertical) valley shape (Fig. 28c; see Fig. 24 and S4-2_Tab.2, location 7). It has a thickness of 7.5 m and contains the most differentiated and complete Upper Pleniglacial sequence for the region. Above a fragment of relocated Middle Pleniglacial brown soil material, a series of alternating laminated partially cryoturbated loess, and cryosols follows (palaeosols E0 to E4).

Loess of the Lower Pleniglacial in FHM seems to accumulate as alluvial loess, whereas younger loess deposits accumulate as aeolian loess. In slope positions alluvial loess is not preserved (Reinecke, 2006).

Fig. 28: Selected and simplified loess sections from northern foreland of the Harz Mountain (redrawn after Reinecke, 2006). Luminescence ages (IRSL50 without fading correction) where adopted from Reinecke (2006) for Ermsleben and Schadeleben and Krauß et al. (2016) for Hecklingen. For locations see Fig. 24, further details in S4-2_Tab.2.

74 | STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY

4.5 Geomorphological position and palaeoclimate as steering factors for loess preservation 4.5.1 Loess preservation and accumulation as a function of the geomorphological position In contrast to other well-known loess regions, such as the middle and lower Danube including the Carpathian Basin (e.g., Stevens e al., 2011; Markovic et al., 2015 and references therein) or sections from the Chinese Loess Plateau (Kukla and An, 1989; Sun et al., 2006; Stevens et al., 2007), Central Europe was situated in a periglacial environment during glacial times with fluctuating boundaries of continuous and discontinuous permafrost (Huijzer and Vandenberghe, 1998; Renssen and Vandenberghe, 2003; Vandenberghe et al., 2012). The environmental conditions were highly variable and erosive processes (slope wash and deflation) frequently occurred. As a result, the temporal resolution and thickness of LPS can vary on the local scale, such as slopes and palaeochannels, but also on larger scales between different loess areas. Additionally, the distance to a dust source plays an important role as high accumulation rates can hamper erosion and protect underlying sediment.

The sediment source and the distance influence the amount of dust accumulation occurring at a locality. In the LRE, the large river systems of Rhine and Meuse (e.g., Henze, 1998; Smalley et al., 2009) and the exposed shelfs of the Channel and North Sea act as main sources for deflation (Smykatz-Kloss, 2003; Antoine et al., 2009). According to heavy mineral analysis, Janus (1988) also mentioned the Eifel tributaries such as Rur, Erft and Niers as an important sediment source which incise into the vast plains of the LRE. In the FHM, the outwash plains in front of the Scandinavian ice sheet served as main dust sources. Additionally, the local glaciation of the Harz Mountains (elevations up to 1,300 m asl and glaciers that descend down to 550 m asl; Duphorn, 1968; Hövermann, 1974) causes alluvial fans in front of the mountains which are very likely a deliverer of source material.

As pointed out by Sima et al. (2009), the major dust accumulation is driven by westerly winds during seasons of reduced vegetation cover during interstadials, stadials and Heinrich events. However, especially for the LGM, new modelling results from Ludwig et al. (2016) indicate an increasing southern and eastern wind component due to the formation of strong anticyclones over the Scandinavian ice sheet. The combination influenced the LRE as well as the FHM. In the LRE, image analysis (Dietrich and Seelos, 2010) and heavy mineral analysis (Römer et al., 2016) of sediments from the Dehner maar core confirm an increasing eastern wind component during the LGM. Krauß et al. (2016) confirm a strong south-eastern wind component for the Hecklingen section in the FHM. An increase in grain size and the mineral composition indicates a changing dust source connected to Bundsandstone bedrock exposures North and East of the profile.

Besides such ‘primary sources’, the reworking of older sediments is an additional important contributor to the sedimentary budget (van Loon, 2006). However, the advance of STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY | 75 the Scandinavian ice sheet towards the mountain front of the FHM during the Saalian glaciation removed all pre-Weichselian sediments. Consequently, these sediments were not available for reworking and deposition (Fig. 28, Reinecke, 2006). In the LRE the Saalian ice sheet reached the area north of Düsseldorf so sediments of Saalian and pre-Saalian age can be found in many LPS (Schirmer, 2016 and references therein). In deposits of the last glacial cycle, the volcanic mineral content associated with the middle-Pleistocene volcanism in the eastern Eifel decreases from the Middle Rhine valley downstream towards the LRE, which was interpreted as frequent reworking and homogenization of older sediments by deflation during later periods (Razi Rad, 1976; Janus, 1988; Henze, 1998). The strong erosion phases recorded in the LPS of the LRE (e.g., Fig. 27, a-c) document the frequent reworking and deposition cycles, occurring especially during climatic turnovers. The absence of pre-Eemian sediments in the FHM generally reduced the potential amount of deflatable material which could have influenced the generally reduced thickness compared to the LRE (cf. Fig. 22 and Fig. 24).

In addition, the geologic bedrock underneath the Pleistocene loess plays an important role concerning the efficacy of geomorphological processes. Below its soils, the LRE consists mainly of unconsolidated Palaeogene to Neogene and Quaternary sediments. The large exposures in the LRE have shown that the palaeo-surfaces varied between different stages, for instance features such as slope angle and aspect (Kels, 2007). Due to the loose underlying sediments, the topography was more dependent on the climatic conditions and formative processes occurring in a periglacial environment leading to continuously changing sedimentary traps. The low relief energy should also have reduced the rate of sediment removal from the system. Therefore, in the LRE the evolution of the loess landscape was controlled by periglacial, fluvial and aeolian process (cf. Fig. 27). In contrast, the FHM consists of Mesozoic and Cenozoic bedrock forming an undulating landscape (cf. Fig. 25). The higher relief energy increased the intensity of periglacial erosive processes. However, if the loess cover is eroded, frost-shattered debris may be introduced, as was observed for the Middle Pleniglacial sequence of Hecklingen by Krauß et al. (2016). Therefore, the bedrock geology of the FHM also controls the periglacial processes and the loess thickness. The temporal resolutions of LPS vary in both areas. In remarkable accordance is the cover loess of the very arid and cold UPGb which is the most extensively preserved sequence of the last glacial cycle. Within this period no strong erosion event is documented. Loess covers the previous landscape like a veneer. It was a period of outstandingly strong loess accumulation and the relief played only a subordinate role due to reduced periglacial processes. In general, the last glacial cycle is characterized by alternating stadial and interstadial phases, erosion always occurred when the landscape was open and assailable. Therefore, it is useful to have a closer look on the stratigraphy and the climatic indications.

Schirmer (2003; 2016) supposed that the strong erosion at the UPGa/UPGb boundary (Eben unconformity) was caused by deflation and intensive and extensive slope wash leading to a

76 | STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY

deep incision in the underlying sediments. Reinecke (2006) also mentioned a strong erosion event controlled by precipitation which led to gully formation directly below the E4 soil at Thale (No. 8 in Fig. 24; see supplement). Additionally, the relocation processes due to melting snow cover during Phase A (UPGa, Fig. 26) were thought to support the reduction of the loess cover in flat positions and subsequent accumulation along slopes in the FHM (Reinecke, 2006). In both areas, the UPGa and the MPG are only preserved in specific geomorphological situations (Hecklingen, Ermsleben, Schadeleben, Grafenberg, and Lommersum). High accumulation rates of primary and reworked loess, and soil sediments can preserve the underlying sediments from erosion. In flat topographies, accumulation is reduced due to the lower amount of sedimentary traps and relocation processes are more extensive.

4.5.2 Stratigraphy and palaeoclimate implications Almost complete and continuous LPS of the last glacial cycle are not recorded in the Central European loess area. Larger erosional gaps were associated with the major climatic changes such as the EG/LPG, MPG/UPG and UPGa/b boundaries for the last glacial cycle. These phases are accompanied by patterns of characteristic geomorphological processes (e.g., slope wash, solifluction, and deflation). The magnitude of the processes is controlled by the morphological setting, vegetative cover, palaeowind intensity, temperature, and humidity, and hence determines the preservation of LPS. The sections presented in Fig. 27 and Fig. 28 are outstanding examples for visualising the general succession of processes in both areas.

During interglacial and interstadial phases, soil formation and vegetation cover stabilized the surface. The fluvial system changed from braided-river to anastomosing and meandering rivers, reducing the sediment supply for deflation and loess accumulation (van Huissteden and Kasse, 2001). The transition into stadial conditions started with cooling, a retreat of vegetation and erosion (Antoine et al., 2009, 2013 and references therein). As examples, the sections Garzweiler South and Elsbach Valley show that linear erosion and gully development are the characteristic features of the beginning of the Lower Pleniglacial on gentle stretched slopes and within older palaeochannels (see Fig. 27 b, c). Such erosion characteristics can also be observed for pre-Eemian sediments at Erkelenz and Garzweiler South (Fig. 27 b, c). On plateaus or very slightly inclined slopes, such as Rheindahlen, the Eemian and Early Glacial soils are preserved and were not affected by incision during the Lower Pleniglacial. Along many LPS of the open-cast lignite mine Garzweiler this sequence even acts as a marker bed due to its good preservation (Fig. 27 a, b; cf. Kels, 2007). The relocated, laminated sediments (Niedereschbach Zone) consist of reworked older soil material intercalated with fresh primary loess. It was followed by the deposition of primary loess with intercalated weak soil formations (cf. local stratigraphy of the LRE in Fig. 26). In the FHM only reworked remnants of the Eemian and Early Glacial soil formations were found within the Lower Pleniglacial deposits of Ermsleben (cf. Reinecke, 2006). The Lower Pleniglacial deposits mainly consist of STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY | 77 reworked and sandy-laminated loess with post depositional cryoturbation. Within this sequence, a cryosol (Hecklingen soil) was developed. At its top, a gravel layer shows that erosion took place after this short phase of surface stabilisation (Reinecke, 2006), possibly also controlled by strong surface runoff. This unit and the Niedereschbach Zone can be found along gentle slopes, slope toes and depressions, where they frequently protected subjacent layers from erosion (Fig. 26). These observations are indicators for higher precipitation and slope wash compared to the Upper Pleniglacial in the LRE where niveo-aeolian loess is the dominant facies (Kels, 2007), but also – possibly with lower intensity – in the FHM.

The erosion event at the MPG/UPG boundary can be observed in nearly every loess section containing these units. Currently the environmental conditions of the transition are not well understood and further investigations is necessary (e.g., Terhorst et al., 2015). Brunck et al. (2016) presented the ELSA Flood Stack based on maar lake sediments of the Eifel Volcanic fields. It also provided information about extreme weather events per 1000 years. For the transition from the Middle to the Upper Pleniglacial, frequent extreme weather events were recorded which could be responsible for the strong relocation processes by slope wash in the loess area. Indications are relocated soil sediments with the facies of an in-situ soil comparable to Middle Pleniglacial cambisols. These units were dated to the Upper Pleniglacial (e.g., Reinecke, 2006; Bibus et al., 2007; Frechen and Schirmer, 2011; Meszner et al., 2013). However, during the MPG itself, several phases of reworking occur. The comparison of high resolution records including several palaeosols such as Schwalbenberg II (Schirmer, 2012), Ermsleben (Reinecke, 2006) or Nussloch (e.g., Antoine et al., 2001, 2009) with other sections show that mainly the Lohne Soil is preserved. It is obvious that the short stadials were also accompanied by erosion processes. In the vast plains of the LRE, the entire Middle Pleniglacial sequence is missing except for small remnants in favourable geomorphological positions such as Garzweiler South (Fig. 27 a), and Grafenberg (Henze, 1998; Schulte et al., 2016) and Lommersum (Brunnacker et al., 1978, Brunnacker and Hahn, 1978). However, it is difficult to determine if the absence of these units in the LRE was caused by erosion during the MPG, MPG/UPG-boundary or due to the deep unconformity at the UPGa/b transition. Comparable observations were made in FHM, where there are currently only two known sections contain MPG sediments. Krauß et al. (2016) pointed out that nearly the entire MPG sequence at Hecklingen was affected by erosion in the catchment leading to the deposition of soil sediments at the investigated position. As a result, differentiating soil and soil sediments is difficult. Comparing both areas, it seems that climatic conditions were similar, or at least that phases of erosion occur simultaneously. The strong erosion event at the UPGa/b boundary shows a completely different behaviour than the EG/LPG transition displaying extensive, more or less, horizontal erosion instead of linear incision (see Fig. 27 a-c; S4-1_Tab. 1). It cuts older sediment regardless of its composition, resulting in a general flattening of the morphology. The topographic position seems to hold a lesser significance. These properties of the UPGa/b transition are indicative of two separable phases. Firstly, a strong phase of

78 | STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY

deflation of a frosted and dried surface as indicated by frost cracks and wind-polished artefacts plus the occurrence of small pebbles directly on top of the unconformity (Meijs, 2002); possibly connected to the second Greenland dust peak (Fig. 26). Secondly, a phase of intensive slope wash which filled the basal frost cracks. Extreme weather events reached a maximum around the boundary between 23 and 24 ka recorded in the ELSA Flood Stack (Brunck et al., 2016). This strong series of events mainly occurred in the LRE, but was described with lower intensity in, for instance, Hesse (Semmel, 1968) and the FHM (Reinecke, 2006). Reinecke (2006) associated the boundary in the FHM with the end of the dominance of slope formation processes (slope wash and re-deposition as laminated loess mainly on slopes with eastern aspect) during the Upper Pleniglacial. Afterwards, the system changed and the subsequent deposition of primary loess was no longer controlled by aspect, and therefore slope processes. The post-UPGb loess covers the entire area with a similar thickness (Reinecke, 2006). At the FHM, sediments older than UPGb can be found on favourable geomorphologic settings such as footslope positions only.

Both unconformities showed that climatic conditions during a glacial phase as well as the morphology played a major role in determining the type and magnitude of erosional periglacial processes and their relevance for the geomorphological setting (c.f. Semmel, 1989). Due to the strong geomorphological processes, the resolution of LPS is generally low in the flat plain, but can be relatively high if the topography promotes preservation. LPS on footslopes and depressions profit from the relocation processes occurring at higher positions on the slope. The subsequently deposited material protected these units at the footslopes from further erosion processes.

Lehmkuhl (2016) shows that for continental areas in Central Asia (e.g., Altai Mountains) that periglacial features (such as solifluction), distribution of permafrost and involutions have different sensitivities to climate besides temperature, especially moisture. The moisture supply and the water content of sediments are the predominate factors which control periglacial landform generation (Lehmkuhl, 2016 and references therein).

4.6 Conclusions The main distribution of loess within the northern European loess belt is situated at the northern front of the Central European Mountains, in basins below 200 to 300 m and partly below 400 to 500 m in southern Germany. This distributional pattern of aeolian sediments is controlled by sediment availability (e.g., distance to larger river systems and the ice sheet) and prevalent wind directions. The distribution of loess deposits in the LRE and FHM is mainly controlled by the large scale and local topography. Examples especially from the long sections in the LRE show clear differences in the presence and properties of loess related to the (meso-) relief. Loess sections in depressions, palaeochannels and on flat/stretched slopes and slope toes show a larger (and sometimes local) variety of LPS than plateau situations with STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY | 79 extensive erosion and thus unconformities. The FHM has a more undulating relief developed on bedrock with a generally thinner loess cover. The thinner loess cover is caused by the absence of pre-Saalian loess for reworking processes (due to the Saalian ice advance) and the steeper Harz Mountains including the smaller bedrock saddle structures. However, entire subsequences (MPG, UPGa) of the last glacial cycle are missing in the vast plains of the LRE as well as in the flat areas of the FHM. High resolution LPS are restricted to favourable geomorphological settings where the magnitude of periglacial erosive processes was reduced or the subjacent units were protected by relocated sediments. Thus the regional setting clearly has a major influence on the formation and preservation of LPS.

In the oceanic LRE more humidity enhanced the periglacial processes which increase erosion, but lead to preservation in accumulative positions. In contrast, in the more continental FHM the sediments were affected by less intensive periglacial processes and no solifluction can be detected.

Primary loess and reworked loess-like material can cover in-situ formed soils and preserve them. Slope wash and solifluction occur at different intensities depending on slope position. Within footslope positions and depressions there is greater thickness and higher resolution, and the intensity of soil development is generally stronger, although the palaeosols might be slightly eroded (S4-1_Tab.1 and S4-2_Tab.1). Depressions are the most promising morphological situation with high accumulation rates and pedogenesis. Relocation and periglacial processes play only a subordinate role depending on the slope of the surrounding topography and the form of the depression itself. Resolution and thickness reach the highest degree in these situations.

Based on these observations and under consideration of modern analogues, some statements about the palaeoenvironmental evolution can be made for the transition of the Middle into the Upper Pleniglacial and the entire OIS 2 for both areas.

1. The transition from the Middle Weichselian to the Upper Pleniglacial starts with a moderate humidity controlled erosion and a shift to cold humid conditions with the typical niveo-aeolian loess facies (mainly preserved in the FHM, but documented for many Central European loess sections). The humidity at the beginning of phase A (UPGa, Fig. 26) coincides with the growing ice sheets and glaciation. In phase B (UPGb, Fig. 26) the ice sheet stagnates and then retreats and the final accumulation of loess during a dryer climate occurs.

2. The decreasing humidity towards the UPGa/b boundary (Fig. 26) promotes the intensity of dust storms inducing the strong and extensive deflation of the Eben unconformity which was followed by extreme precipitation events (Kesselt Layer, reworked sediments) in the LRE.

3. Between 24-23 ka a major change in the type of loess sedimentation occurred in the entire Central European loess area from niveo-aeolian to primary loess (cover loess). Shortly

80 | STUDY 1: LOESS-PALEOSOL SEQUENCES AT THE NORTHERN EUROPEAN LOESS BELT IN GERMANY

after the first deposition, soil formation occurred (E4 Soil). In the LRE, it is more intensive and affected by massive solifluction; hence enough soil moisture must be present. In the FHM, it is also the strongest cryosol, but less intensive and without solifluction.

4. Towards the end of the Weichselian, in both regions cold and dry climate conditions become dominant, as they did in the whole of Central Europe. The UPGb cover loess was deposited extensively along the northern European loess belt (Fig. 18). This major phase ended with the Bölling-Alleröd interstadial, but a last loess input possibly occurred above.

Sedimentation, soil formation and preservation of aeolian sediments is dependent on various environmental and geomorphologic conditions on various scales from several meters (slope position) to hundreds of kilometres as indicated by systematic differences between the LRE to the FHM. This calls for a detailed understanding of processes, from micro- to meso- to macro landscape scale, accompanied by the development of models to understand recent landscapes and their recent morphology for the last glacial cycle in Central Europe. More supraregional comparisons would be helpful for understanding of LPS in Central Europe.

STUDY 2: The Eltville Tephra (Western Europe) age revised | 81

5 The Eltville Tephra (Western Europe) age revised: integrating stratigraphic and dating information from different Last Glacial loess localities

Joerg Zensa*, Christian Zeedena, Wolfgang Römera, Markus Fuchsb, Nicole Klasenc, Frank Lehmkuhla

a Department of Geography, RWTH Aachen University, Templergraben 55, 52056 Aachen, Germany

b Department of Geography, Justus-Liebig-Universität Gießen, Senckenbergstraße 1, 35390 Giessen, Germany c Department of Geography, University of Cologne, Albertus-Magnus-Platz, 50923 Cologne, Germany

* corresponding author: [email protected]; +492418096476

Published 2017 in Palaeogeography, Palaeoclimatology, Palaeoecology Volume 466, 240-251.

Abstract

The Eltville Tephra (ET) is an important stratigraphic marker bed in the Western European loess stratigraphy at the boundary between the regional Last Glacial Maximum (LGM) in the sense of the maximum extent of glaciation of the Scandinavian ice sheet and a ‘terrestrial’ LGM with the highest degree of aridity and coldness. Stratigraphic marker beds such as tephra layers are commonly dated at more than one location, and often with more than one method. The sediments surrounding the ET were dated 87 times at 15 localities with different luminescence techniques yielding ages between 13.5 and 49.6 ka. Based on individual sections, the deposition of the ET was supposed to have taken place between 20 and 23 ka. This raises the question of whether a quantitative combination of individual ages can give a reproducible common age, including uncertainties. After screening the dataset and applying selection criteria, a Bayesian resampling approach is applied to obtain a common age consistent with a high percentage of observations from multiple localities.

Four new luminescence ages bracketing the ET and two ages directly generated from the tephra horizon are presented and combined with all available data. The 1σ age range of the Bayesian age modelling yields a deposition age between 23.2 and 25.6 ka, which is in excellent agreement with two new luminescence ages from the tephra of 24.1±1.9 ka (quartz) and 24.3 ± 1.8 ka (pIRIR290) and a peak of volcanic minerals in the Dehner maar core around 24.3 ka. This age is clearly older than previously suggested for the ET volcanic eruption, but fits better with stratigraphic and palaeoenvironmental evidence. Therefore, the ET was deposited during phases of strong aeolian activity of the Greenland Stadial 3. Additionally, for the first

82 | STUDY 2: The Eltville Tephra (Western Europe) age revised

time, a correlation can be made between the ET and tephra layers recognized in the Eifel maar lake cores.

5.1 Introduction The Eltville Tephra (ET) is a volcanic ash erupted from an unknown volcano of the Eifel Volcanic Fields (central Europe) during the Weichselian Upper Pleniglacial (UPG). It is widely distributed over Western and Central Europe (Fig. 29). The ET serves as an important stratigraphic marker bed for loess-palaeosol sequences in Western and central Europe (Fig. 31) Dating methods are limited in accuracy and precision when applied to loess which underwent varying accumulation rates, weak soil formation and erosion on millennial time scales. Dating results often disagree with stratigraphic order and expectations (e.g. Lang et al., 2003; Frechen and Schirmer, 2011). As a consequence, characteristics of sedimentary units (e.g. colour, grain size distribution, pedological/sedimentary features) were often used for comparisons between loess-palaeosol sequences and to independently-dated records by event-based correlations (e.g. Antoine et al., 2009, 2013; Moine, 2014; Haesaerts et al., 2016; Schirmer, 2016). However, the determination of the start and ending of soil formations and other sedimentary units remains difficult. In contrast, tephra layers are self-contained, temporal synchronous events which can be dated directly (especially by Ar40/Ar39 dating; cf. Bogaard, 1995; Kuiper et al., 2008; Rivera et al., 2011, 2013). Therefore, a precise and accurate deposition age of tephra layers is a very useful and powerful tool to reduce the uncertainty and improve the reliability of correlations and chronologies (cf. Vandergoes et al., 2013).

In Western and central European loess stratigraphy, four tephra layers are well-known for the Last Glacial cycle: the Laacher See Tephra, the Eltville Tephra, the Rambach Tephra and the Rocourt Tephra (cf. Fig. 31). The Laacher See Tephra was dated directly by 40Ar/39Ar dating (Bogaard, 1995) and crosschecked with 14C (Baales et al., 2002) yielding an age of 12.9 ka. The Rocourt Tephra was dated stratigraphically to 74.0-90.3 ka (Pouclet and Juvigne, 2009). For the Eltville and Rambach Tephras a large amount of luminescence ages is available, bracketing these layers, especially for the ET.

Luminescence dating techniques can be applied to sedimentary mineral grains (quartz, K- feldspar, zircon) to date the last exposure to sunlight. The luminescence signal arises from ionized radiation penetrating the mineral after deposition. Electrons within the crystal lattice are raised to higher energy levels and were captured in lattice defects. When exposed to sunlight or artificially stimulated by heat (thermoluminescence, TL) or light of different wavelength (e.g. infrared, IRSL; blue, green, OSL), the trapped electrons are released and emit photons originating from the accumulated excess energy (luminescence signal). The division of the accumulated dose by the environmental dose rate results in the depositional age (e.g. Aitken, 1998). Loess appears to be a suitable sediment due to its aeolian origin. This implies good conditions for complete signal resetting (bleaching) prior to deposition (Roberts, 2008). STUDY 2: The Eltville Tephra (Western Europe) age revised | 83

Luminescence dating has frequently been applied to establish numerical chronologies for loess records by different techniques (e.g. Wintle and Brunnacker, 1982; Zöller et al., 1988; Frechen, 1999; Thiel et al., 2011a; Kreutzer et al., 2012a).

The sediments bracketing the ET have been dated using a number of luminescence dating techniques yielding ages between 13.4-49.6 ka (see S5_Tab. 1). Due to the broad scatter of ages, attempts to calculate average ages or meaningful estimates have been provided by various authors. These studies suggested a deposition around 20 ka (Pouclet and Juvigné, 2009), 20-23 ka (e. g. Zöller, 1995; Frechen and Preusser, 1996; Lang et al., 2003; Antoine et al., 2009; Klasen et al., 2015a) or 20-25 ka (Gocke et al., 2014). However, the age estimates do not agree with correlations of event-based chronologies for Western and central European loess which are based on Greenland ice core data. Additionally, the age estimates tend to be inconsistent with respect to age estimates of the ET among each other (cf. Antoine et al., 2009; Meijs, 2011; Haesaerts et al., 2016; Schirmer, 2016). In all cases, a deposition prior to the Greenland interstadial 2 (22.9 ± 0.6 to 23.4 ± 0.6 ka, Rasmussen et al., 2014) is assumed. In addition, within the Eifel-Laminated-Sediment-Archive (ELSA) (Sirocko, 2016) no tephra was found corresponding to these suggestions although the ET originated from the Eifel Volcanic Fields (Sirocko et al., 2013, 2016; Förster and Sirocko, 2016).

The inconsistency between stratigraphic models and different archives of the UPG sediments highlights the importance of the ET as a chronological marker. A revised age of the ET may provide an important chronological marker for the correlation of loess-palaeosol sequences and different palaeoclimate archives at different spatial and temporal scales. It can improve, refine or challenge chronologies based on event-based correlations. The aim of this study was to produce a reproducible chronological marker using selective re-sampling statistics corresponding to Bayesian age depth modelling based on luminescence ages, similar to the approach of Vandergoes et al., (2013) who used 14C dates for the same purpose. We have compiled all known published and unpublished luminescence ages bracketing the ET

(n=83) from 15 locations. We have extended the dataset by four new blue OSL and pIRIR290 luminescence ages from the loess section Romont (Belgium). The result has been crosschecked by two new luminescence ages generated directly from the ET for the first time. The revised depositional age has been brought in to the existing stratigraphical context as evidence to determine palaeoenvironmental implications.

84 | STUDY 2: The Eltville Tephra (Western Europe) age revised

Fig. 29: Distribution map of the Eltville Tephra. The black dots show undated loess sections with reported occurrence of the ET; black triangles indicate dated sections. The black lobe shows the spatial distribution after Meijs et al. (1983) modified by Juvigné. Distribution map of the Eltville Tephra. The black dots show undated loess sections with reported occurrence of the ET; black triangles indicate dated sections. The black lobe shows the spatial distribution after Meijs et al. (1983) modified by Juvigné (1999). The potential source regions are the West Eifel Volcano Field (WEVF) and the East Eifel Volcano Field (EEVF). The Dehner (dry) maar (red star) is shown because it includes two tephra layers for the UPG (Förster and Sirocko, 2016). It is an important regional and constant archive of aeolian deposition for the time slice 40.3 ka – 12.9 ka BP (Dietrich and Seelos, 2010). Loess distribution according to Haase et al. (2007), modified with data from Zagwijn and van Staalduinen (1975) and Haesaerts et al. (2011a) for The Netherlands and Belgium.

5.2 The Eltville Tephra 5.2.1 Appearance, properties and distribution The ET consists of five differently-coloured tephra layers. All tephra layers are mixed with loess. Individual ash layers are separated by thin loess deposits if more than one layer is preserved (cf. Meijs et al., 1983, Fig. 30a). The mineral composition is dominated by clinopyroxene, olivine and brown hornblende (Frechen, 1959; Bibus, 1973; Juvigné and Semmel, 1981; Meijs et al., 1983). The composition is comparable to other alkaline basaltic volcanoes of the Quaternary Eifel Volcanic Fields. The source volcano is still unknown. From STUDY 2: The Eltville Tephra (Western Europe) age revised | 85 the hypothetic eruptive centre in the surrounding of the East Eifel (Bibus and Semmel, 1977; Meijs et al., 1983; Pouclet and Juvigné, 2009) or West Eifel Volcanic Field (Löhr, 1987; Weidenfeller et al., 1994; Förster and Sirocko, 2016), the thickness of ash layers and intercalated loess (ET sequence) decreases from 4 to 20 cm from the Eifel Mountains and Middle Rhine Valley to less than half a millimetre in eastern Belgium and southern Lower Saxony. The maximum thickness of 20 cm was observed on a northern exposed slope between the villages of Plattern and Zeltlingen within the Eifel Mountains (Löhr, 1987).

The ET occurs in the loess regions of eastern Belgium, the southern Netherlands, Western and central Germany. The depositional trend extents in easterly direction. Fig. 29 shows localities with ET occurrence based on published and unpublished data (Schönhals, 1959; Rohdenburg and Meyer, 1966; Semmel, 1967, 1968; Semmel and Stäblein, 1971; Bibus, 1973, 1974, 1989, 2002; Löhr and Brunnacker, 1974; Bibus and Semmel, 1977; Meijs et al., 1983; Vreeken, 1984; Löhr, 1987; Juvigné and Wintle, 1988; Zöller et al., 1988; Rösner, 1990; Juvigné, 1992; Boenigk and Weidenfeller, 1994; Henze, 1998; Preusser and Frechen, 1999; Bibus, 2002; Smykatz-Kloss, 2003; Schmidt, 2014; Klasen et al., 2015a). Meijs et al. (1983) and Juvigné (1999) have provided a map by assuming that the extent of the ET deposition lobe ranges form a deposition boundary in the east of Nürnberg and in the south of Karlsruhe. The north-eastern extent of the tephra deposition area is located near Göttingen where the ET thickness is less than 1 mm (Rohdenberg and Meyer, 1966). The southernmost occurrence of the ET appears to be Gemmrigheim. Based on current available data, the most eastern extent is in the area of Kitzingen, though the spatial extent of the ET remains disputable due to problems of visual identifications. However, the map drawn by Meijs et al. (1983) and modified by Juvigné (1999) provides a good generalized overview of a likely maximum spatial dispersal of the ET (Fig. 29).

Fig. 30: Photos of the Eltville Tephra from Ringen (A, Germany) and Romont (B, Belgium). (A) The ET is divided into five different bands (circles) with an overall thickness of 4 cm. The punctual features interrupting the ET originate from bioturbation due to earth worms (red rectangles). (B) The ET is only preserved as a single layer of less than 1 cm thickness. The undulating appearance is the result of cryoturbation. (Photos: J. Zens)

86 | STUDY 2: The Eltville Tephra (Western Europe) age revised

5.2.2 Stratigraphical position and importance as a marker bed The distribution of the ET covers several subareas (Belgium, Lower Rhine Embayment, Middle and Upper Rhine Valley, Hesse and Lower Saxony) in the European Loess Belt. A major problem of assigning the stratigraphic position of the ET arises from the use of local assignments in the stratigraphic schemes in the different subareas which take account to regional characteristics (e.g. Schönhals et al., 1964; Rohdenburg and Meyer, 1966; Bibus, 2002; Haesaerts et al., 2016; Schirmer, 2016). The usage of individual nomenclatures for palaeosols complicates comparisons of loess records from different areas. In addition, the soil type of pedological layers varies between stratigraphic schemes, for examples, the E4 soil is denoted as a calcic regosol in the Lower Rhine Embayment (Schirmer, 2016) and as a tundra gley at Nussloch (e.g. Antoine et al., 2009) and Saxony (Meszner et al., 2013). Fig. 31 shows a simplified lithostratigraphy for the Last Glacial cycle that has been modified according to Schönhals et al. (1964), Bibus (2002) and Haesaerts et al. (2016) and will be used in this study. Palaeosols and sedimentary units have been grouped and modified according to Antoine et al. (2016) into Eem Interglacial, Early Glacial (EG), Lower Pleniglacial (LPG), Middle Pleniglacial (MPG), Upper Pleniglacial (UPG) and Late Glacial (LG).

The UPG is divided into two sub stages which we have termed Phase A and Phase B according to Lehmkuhl et al. (2016). A similar subdivision is used in Belgium and in the Lower Rhine Embayment dividing the niveo-aeolian Hesbaye (~32-23 ka) and homogenous Brabant loess (~23-14.7 ka; cf. Gullentops, 1954; Henze, 1998; Huijzer and Vandenberghe, 1998; van Huissteden and Kasse, 2001; Meijs, 2002; Antoine et al., 2003, 2009; Meszner et al., 2013; Moine, 2014; Haesearts et al., 2016; Schirmer, 2016). The subdivision is supposed to reflect the regional LGM in the sense of the maximum extent of glaciation in Europe (cf. Antoine et al., 2009) and the following deglaciation which coincides with the coldest and most arid conditions in the terrestrial environment (cf. Moine, 2014).

Phase A has been characterized by humid-cold climatic conditions. The loess of these period contains cryosols and the Rambach and Eltville Tephras. According to pollen data of the ELSA vegetation stack, the landscape was dominated by a grassland steppe until 28 ka leading over to a tundra environment until 23 ka (Sirocko et al., 2016). Loess profiles of this phase shows a fine laminated niveo-aeolian facies which will be attributed to seasonal thawing of snow (e.g. Huijzer and Vandenberghe, 1998; Antoine et al., 2009; Kadereit et al., 2013; Meszner et al., 2013; Moine, 2014). Phase A includes several cyrosols of different intensity (E0-E3 soils) and the Rambach and Eltville Tephras. The Rambach Tephra appears as a single band embedded in laminated loess between the E0 and E1 soils. The spatial distribution of this tephra layer is limited to the Middle Rhine Valley and the Rheingau (Semmel, 1967). TL datings around the Rambach Tephra yielded ages between 32 and 28 ka (Buschbeck et al., 1992; Zöller, 1995; Radtke et al., 1998). The ET is situated above the E3 soil embedded in laminated niveo-aeolian loess. It provides the lower stratigraphic marker for the sedimentary sequences reflecting the transition from humid-cold to cold-arid conditions STUDY 2: The Eltville Tephra (Western Europe) age revised | 87

(Phase A/B transition). The eruption is supposed to have taken place between 23 and 20 ka (e.g. Zöller, 1995; Frechen and Preusser, 1996; Lang et al., 2003; Antoine et al., 2009; Pouclet and Juvigné, 2009; Klasen et al., 2015a). The deposition of the niveo-aeolian loess ends in general several decimetres above the ET. In sediment traps like dry valleys, the niveo-aeolian loess may reach a thickness of more than 3 m which appears to indicate strong wind dynamics during and after the deposition of the ET (Meijs et al., 1983). From Northern France towards the Lower Rhine Embayment, the loess sections are characterized by the Eben unconformity. This unconformity results from an erosional event which cuts mostly horizontal or weakly inclined older soils and sediments and changed the topography of the entire area (Meijs, 2002; Schirmer 2003, 2016; Kels, 2007). It is supposed to be caused by intensive precipitation and/or strong deflation (Gullentops and Meijs, 2002; Meijs, 2002; Schirmer, 2003, 2016). Cryoturbated and reworked sediments of this event (Kesselt Layer, cf. Fig. 34) consists of soil remains and loess which fill small frost cracks occurring at the surface of the Eben unconformity. Sometimes, it is split in a fine stratified package of sand, gravels and silt at the base and more homogenous loess with intercalated soil remains in the upper part (Schirmer, 2003, 2016). It is attributed to be the latest unit of the Upper Pleniglacial (Gullentops and Meijs, 2002; Schirmer, 2003).

Phase B is was characterized by very cold and arid conditions with permafrost advances (Huijzer and Vandenberghe, 1998; Gullentops and Meijs, 2002; Antoine et al., 2003, 2009; Moine, 2014) in a polar desert environment (Sirocko et al., 2016). The homogeneous loess of this phase covers the landscape and this loess surface largely corresponds with the recent relief (Henze, 1998; Meijs, 2002; Antoine et al., 2003). The base of Phase B is marked by the E4 soil (e.g. Rohdenburg and Semmel, 1971; Löhr and Brunnacker, 1974; Henze, 1998; Van den Haute et al., 1998; Schirmer, 2002a; Meszner et al., 2013) which is also known as the Nagelbeek Complex from Belgium (NC; Haesaerts et al., 2016). It is the strongest phase of soil formation during the UPG. The E4/NC is tripartite, whereas the lower two units are highly cryoturbated due to solifluction. It represents a climatic warming with increasing vegetation (Semmel, 1968; Gullentops and Meijs, 2002; Schirmer, 2003) and moisture (Moine et al., 2008). TL ages of the boundary between Phase A and Phase B by Van den Haute et al. (1998) range from 22 and 20 ka at the section of Kesselt. According to quartz OSL ages from Kreutzer et al. (2012a), Meszner et al. (2013) suggested the boundary around 22 ka. Vandenberghe et al. (1998) place the formation of the E4/NC around 19 ka at the end of the maximum cooling. The E5 soil is a weakly developed cryosol and the latest soil formation of the UPG.

88 | STUDY 2: The Eltville Tephra (Western Europe) age revised

Fig. 31: Simplified and generalized loess stratigraphy for the last glacial cycle in Western and Central Europe with the position of the ET modified according to Schönhals et al. (1964), Bibus (2002) and Haesaerts et al. (2016). The luminescence ages around the ET show wide scattering. LG abbreviates Late Glacial. The NGRIP δ18O and dust content and ice core data (Andersen et al., 2006; Vinther et al., 2006; Rasmussen et al., 2006, 2008, 2014; Svensson et al., 2006, Wolff et al., 2010; Blockley et al., 2012; Seierstad et al., 2014) are plotted as an accurate and independent timescale for the comparison with luminescence ages and represent an additional important climate record of the northern hemisphere during the Last Glacial cycle. GI abbreviates Greenland interstadial and GS Greenland stadial. The Lohne Soil formation has been correlated to the Greenland Interstadials 5 to 8 as a demarcation of the MPG/UPG transition. The precise timing is still under discussion (cf. Antoine et al., 2009; Rousseau et al., 2011; Kadereit et al., 2013, Kadereit and Wagner, 2014; Sauer et al., 2016).

STUDY 2: The Eltville Tephra (Western Europe) age revised | 89

5.3 Material and methods 5.3.1 Luminescence dating The loess section Romont East (N 50.79; E 5.65) is located at the limestone quarry Eben- Emael (Belgium) south of Maastricht on an eastern exposed slope at 110 m asl. The ET can be found in 4.75 m depth as a single ~5 mm thick layer. The section displays the typical stratigraphy of the Phase A/B transition (cf. 5.2.2). Two samples (RMT2_6, RMT2_7) bracketing the ET were taken from 4.71 m and 4.86 m depth.

The loess section Ringen (N 50.570194; E 7.111394) is located at the transition from the Lower Rhine Embayment to the Eifel Mountains and the Middle Rhine Valley on a south- eastern exposed slope in 174 m asl. The ET occurs at a depth of 2.36 and is characterized by five individual ash layers separated by loess with an overall thickness of 3-5 cm. However, in this section the ET is disturbed by recent bioturbation (worm holes, cf. Fig. 30) along the entire exposed wall. Therefore, we have chosen the deepest possible position for sampling in a small palaeochannel which is less affected by bioturbation. The sample RGE-4 was taken directly from the tephra.

The samples were pretreated with HCL (10 %), H2O2 (10 %) and Na4P2O7 (0.01 N) to remove carbonates, organic material and to disperse clay. The polymineral fine grain (4-11 µm) samples were etched with hexafluorosilicic acid to extract fine grain quartz. Luminescence measurements were carried out on a Risø TL/OSL DA 20 reader with a 90SR/90Y beta irradiation source stimulating with blue LEDs (470 nm, FWHM = 20, quartz) and infrared LEDs (870 nm, FWHM = 40, polymineral) for 40 s at 125 °C and 200 s at 290 °C respectively. The luminescence signal was detected using a 7.5 mm Hoya U-340 filter (330 ± 40 nm) for quartz and an interference filter (410 nm) for polymineral samples.

The OSL measurements were carried out using the single aliquot regenerative dose protocol (SAR) (Murray and Wintle, 2000, 2003) and the adjustments for the pIRIR290 signal of polymineral K-feldspar rich samples by Thiel et al. (2011). Preheat-plateau tests for temperatures between 180 and 280 °C where conducted for quartz separates of RMT2_7 and RGE-16, which is located in the sediments directly below the ET. First IR stimulation temperature tests were conducted for the same samples for temperatures between 50 and 180 °C (Buylaert et al., 2012). For polymineral samples, the residual signal measured after bleaching for 24 h in a Hönle SOL2 solar stimulation was subtracted for dose recovery experiments. Fading tests according to Huntley and Lamothe (2001) were applied for sample RMT2_7 and RGE-4.

The environmental dose rate was determined using a high-purity germanium detector. The gravimetric in-situ water content was measured and the correction factors from Zimmermann (1971) were used. Conversion factors of Liritzis et al. (2013), alpha attenuation factor by Bell (1980) and beta attenuation factor by Brennan (2003) were applied. The α-efficiency for quartz

90 | STUDY 2: The Eltville Tephra (Western Europe) age revised

samples was set to 0.036 ± 0.003 (Kreutzer et al., 2012a) and for polymineral samples to 0.08 ± 0.02 (Rees-Jones,1995). The internal potassium content of the K-feldspars was assumed to be 12.5 ± 0.5 % (Huntley and Baril, 1997). The total environmental dose rate and the finale age were calculated using the DRAC online tool, Version 1.1 (Durcan et al., 2015). The complete data table can be found in the supplement (S2, online version of this article). The results of the determination of the total dose rates are shown in Tab. 2.

Tab. 2: Summary of dosimetry data. The water content (WC) is the percentage of the mass of dry sediment. A more detailed overview is given in the shorthand DRAC table of the online version of this article (S2).

Radionuclide concentration DR Sample Lab. Depth U Th K WC Cosmic DR DR Q tot tot PM code code [m] [ppm] [ppm] [%] [%] [Gy/ka] [Gy/ka] [Gy/ka]

RGE-4 C-L3924 2.03 3.22 ± 0.13 10.39 ± 0.50 1.43 ± 0.02 15.7 0.17 ± 0.02 3.23 ± 0.21 3.81 ± 0.22

RMT2_6 C-L4156 4.71 2.88 ± 0.13 10.10 ± 0.50 1.36 ± 0.03 9.9 0.13 ± 0.01 3.19 ± 0.21 3.76 ± 0.22

RMT2_7 C-L4157 4.86 2.72 ± 0.12 9.98 ± 0.49 1.41 ± 0.03 9.7 0.13 ± 0.01 3.19 ± 0.21 3.77 ± 0.22

5.3.2 Integrating age information from different localities for stratigraphic marker beds To obtain an age from a marker horizon, integrating information from several sites, and samples from below and above a specific horizon are useful (cf. Vandergoes et al., 2013). They have shown the potential of such a method using 14C data. In this study, luminescence ages were used in a similar approach. The information of stratigraphic and temporal distance of ages relative to any specific maker is of importance, but the temporal difference is usually of relative nature and hardly quantifiable. In this study, we have assumed that all samples were taken stratigraphically close to the ET, and that no unconformities have occurred close to the ET deposition.

Resampling data is a method of obtaining uncertainty within available information through repeated sampling of data and its (specific) properties. Here we use the mean and 1- sigma uncertainty of published luminescence ages from above and below the ET, and resample these properties multiple times in a Bayesian (selective resampling) approach. We have allowed only results that are consistent with stratigraphy, i.e. all ages above the ET must be younger than all ages below. Then the two datasets are averaged, and finally 1- and 2-σ uncertainties for the datasets above and below the ET have been determined. The applied R code (R Core Team, 2014) is available as supplementary material (S4 of the online version of this article).

STUDY 2: The Eltville Tephra (Western Europe) age revised | 91

5.3.3 Data selection The data consists of 87 published and unpublished luminescence ages bracketing the ET (see Tab. S2, online version). It shows a strong heterogeneity concerning signals, measurement protocols, grain sizes and minerals used. Roberts (2008) mentioned the difficulties to combine data from different publications due to the variation of measurement parameters. Therefore, it is not useful to combine all ages for a calculation, but rather to screen the dataset for the most reliable and robust ages. We have assessed the (i) usage of the single aliquot regenerative measurement protocol and (ii) tests for anomalous fading for feldspars as two major criteria for data selection.

The SAR protocol developed by Murray and Wintle (2000, 2003) was one of the major advantages in luminescence dating originally developed for quartz, and was later adjusted for the feldspar IRSL signal (e.g. Wallinga et al., 2000) and for pIRIR signals of elevated temperatures (e.g. Thomsen et al., 2008; Thiel et al., 2011a; Stevens et al., 2011). It allows for the correction of sensitivity changes occurring during laboratory measurements and significantly improves precision and accuracy of ages compared to the previously used multiple aliquot protocols (cf. Roberts, 2008).

Anomalous fading describes the observation of a signal loss during laboratory measurements which were observed for TL and IRSL signals of feldspars (Wintle, 1973, Spooner, 1992, 1994; Huntley and Lamothe, 2001). The signal may underestimate the age compared to independent age control (e.g. Wintle, 1973; Huntley and Lamothe, 2001; Auclair, et al., 2003). Spooner (1994) suggested that a routine monitoring to proof for the presence of fading is necessary. Several methods were introduced to correct ages if fading occurs (e.g. Huntley and Lamothe, 2001; Auclair, et al., 2003). A signal less affected by fading was observed by Jain and Singhvi (2001), based on higher stimulations temperatures applied after an initial bleaching at lower temperatures leading to the implementation of SAR based protocols for the pIRIR signal of 225°C (Thomsen et al., 2008) and 290°C (Thiel et al., 2011a; Stevens et al., 2011) of feldspars. They yielded good agreement with fading corrected IRSL (Thiel et al., 2011a) and quartz ages (Stevens et al., 2011; Klasen et al., 2015b) and independent age control (e.g. Roberts et al., 2012). However, for the collected pIRIR ages, no fading tests were applied except of the new ages presented here. Therefore, fading cannot be fully excluded and these data were rejected.

Applying the screening criteria (i) measured with the SAR protocol and (ii) test for anomalous fading and correction if necessary, 75 dates have to be rejected. Finally, 5 ages above and 7 ages below the ET remain for the final age calculation (Tab. 3).

92 | STUDY 2: The Eltville Tephra (Western Europe) age revised

Tab. 3: Luminescence ages used for age calculation. A detailed consideration of the stratigraphic relationships provides information on possible unconformities in accordance with the idealized stratigraphies in Fig. 31. SC: stratigraphic context; SAR: Single Aliquot Regenerative Dose protocol. The g-value was calculated according to Huntley and Lamothe (2001). More detailed information is given in the supplementary data (S5_Tab. 1) including all rejected ages.

Sample Age 1-σ Min- SC Signal Protocol Fading Reference Section code [ka] [ka] eral Romont C-L4156 26.0 2.1 E4 - ET pIRIR 290 PM SAR see RMT2_7 This study

Romont C-L4156 25.3 2.1 E4 - ET blue OSL Q SAR - This study Ginseldorf GI26 27.6 4.2 > ET blue OSL Q SAR - Schmidt 2014

Nussloch GI191 22.9 2.2 > ET green OSL Q SAR - Wolpert (2015) Remagen-Schwal- C-L2896 21.3 2.1 > ET blue OSL Q SAR - Klasen et al. 2015a benberg Above ET

Ringen C-L3924 24.3 1.8 ET pIRIR 290 PM SAR g=0.20±0.79% Ringen C-L3924 24.1 1.9 ET blue OSL Q SAR -

below ET

Romont C-L4157 25.1 2.0 E4 - ET pIRIR 290 PM SAR g=0.47±0.28% This study Romont C-L4157 24.5 2.1 E4 - ET blue OSL Q SAR - This study

Ginseldorf GI27 25.9 3.9 < ET blue OSL Q SAR - Schmidt 2014 Nussloch GI190 20.5 2.0 < ET green OSL Q SAR - Wolpert (2015)

Nussloch NUP4-0809 23.1 1.9 ET - E3 blue OSL Q SAR - Tissoux et al. 2010 Nussloch BT1016 27.5 1.8 ET - E3 blue OSL Q SAR - Gocke et al. 2014 Remagen-Schwal- ET - C-L2897 23.0 2.3 blue OSL Q SAR - Klasen et al. 2015a benberg E3/E2

5.4 Results 5.4.1 Luminescence dating of the Eltville Tephra Additionally to the published ages, we have included new luminescence data. The investigated samples show bright luminescence signals. Dose response curves were best fitted to a single saturating exponential function for quartz and polymineral separates (S5-Fig. 1).

Preheat-plateau tests on quartz yielded constant De for temperatures between 200 and 280 °C within 2σ uncertainty (S5-Fig. 2). Dose recovery experiments could successfully reproduce a laboratory irradiated dose for preheat temperatures of 260 and 280 °C (Tab. 4). Therefore, these temperatures where used for the measurement of the burial dose. The De scatter was low and overdispersion did not occur, hence the average mean was used for De calculation (Fig. 32).

First IR stimulation temperature tests on polymineral fine grain separates show constant equivalent doses (De) for temperatures between 50 and 180 °C within 2σ uncertainty. Residual doses after 24h bleaching are below 4 Gy and were subtracted from the De measured for dose STUDY 2: The Eltville Tephra (Western Europe) age revised | 93 recovery tests. Results vary within 10 % of unity (Tab. 4). RGE-4 and RMT2_7 were checked for anomalous fading by determining the g–value (Huntley and Lamothe, 2001; Auclair et al., 2003). The values of g = 0.20 ± 0.35 % (RGE-4) and g = 0.47 ± 1.03 % (RMT2_7) indicate that fading is negligible for the pIRIR290 signal (Tab. 3). We assume that the g-value of sample RMT2_7 is also representative for sample RMT2_6, which was taken from the same sedimentary unit 15 cm above. Low overdispersion was observed for polymineral samples RMT2_6 and RMT2_7, where the Central Age Model (Galbraith et al., 1999) was used (Fig. 32).

Tab. 4: Results of luminescence dating. The dose recovery ratio (DRT ratio) vary within 10 % of unity. More details are given in the DRAC table in the supplementary data S2.

Sample Lab. Sample Residual DRT ratio DRT ratio De PM De Q Age PM Age Q code code position [Gy] [PM] [Q] [Gy] [Gy] [ka] [ka] RGE-4 C-L3924 ET 2.98 ± 0.30 0.93 ± 0.04 0.96 ± 0.02 92.5 ± 4.6 77.8 ± 4.0 24.3 ± 1.8 24.1 ± 1.9

RMT2_6 C-L4156 above ET 2.50 ± 0.17 0.99 ± 0.04 1.01 ± 0.01 101 ± 5.2 80.8 ± 4.1 26.8 ± 2.1 25.3 ± 2.1

RMT2_7 C-L4157 below ET 3.46 ± 0.26 1.00 ± 0.05 1.02 ± 0.01 98.0 ± 5.0 78.2 ± 4.1 26.0 ± 2.0 24.5 ± 2.0

94 | STUDY 2: The Eltville Tephra (Western Europe) age revised

Fig. 32: Albanico plots of the De distribution from the investigated samples. The De scatter is low for all samples. Overdispersion was observed for polymineral separates RMT2_7 and RMT2_6 (2.06±1.2 and 2.37±1.38) where the CAM (Galbraith et al., 1999) was used instead of the average mean for age calculation.

STUDY 2: The Eltville Tephra (Western Europe) age revised | 95

5.4.2 Eltville Tephra age estimates Information from numerous localities (Tab. 3) is used to construct ages with associated uncertainty for the ET. The data are confined by minimum ages below and maximum ages above the ET, and are displayed in Tab. 5. Using 10 times 10,000 successful simulation results in stratigraphic order leads to a standard deviation of maximal 40 years. A comparison of the results of 200,000 resampling runs with those of 10,000 resampling runs indicates that the differences in uncertainty are negligible. As the results of both resampling runs are indistinguishable, we consider calculation uncertainty negligible. The modelling results are in good agreement with the direct ages of the ET from sample RGE-4 (Tab. 4, Fig. 33).

Tab. 5: Results from computing ages for the ET.

Above the Eltville Tephra Below the Eltville Tephra -2σ -1σ median 1σ 2σ -2σ -1σ median 1σ 2σ 200.000 runs 19.81 20.85 21.99 23.17 24.34 24.43 25.59 26.79 27.98 29.18 average mean (n=10) 19.79 20.85 21.98 23.16 24.33 24.43 25.59 26.79 27.99 29.18 standard deviation (n=10) 0.03 0.01 0.01 0.01 0.01 0.03 0.02 0.02 0.02 0.04

5.5 Discussion 5.5.1 Timing of the Eltville Tephra The ET ages including 1- and 2σ uncertainties (Tab. 5, Fig. 33: Probability density functions for 200.000 runs from samples above (grey) and below (white) the ET. Diamonds show the ages generated directly from the ET (sample RGE-4). The combination of statistical parameters for both density functions facing the ET, interlayered between these, lead to depositional periods for the ET with specific uncertainties. Median: 22.0 - 26.8 ka; 1σ: 22.5 - 26.2 ka, 2σ: 24.3 – 24.4 ka. The 1σ uncertainty of the luminescence ages from Ringen are in accordance with the 1σ uncertainty of the modelling results.) are the result of the specific calculation method. The most important assumption is the synchrony of the ET, its correct identification (which is in very most cases supported by the Last Glacial stratigraphy) and the absence of a (long) hiatus between the samples and the ET.

The mean age above and below the ET may be seen as conservative measures of its real age. In an ideal case, the ET was deposited between median values or percentiles of data above and below the ET. However, as not all assumptions made here can be proven in detail suggesting a position between the upper and lower 2σ confidence from below and above the ET may be ambiguous. In our opinion the median values are too conservative as they cover also an interstadial period which do not reflect the environmental conditions during the deposition (cf. 5.2). The 2σ boundaries (24.3-24.4 ka) may be over interpreting data though of the excellent fit with luminescence ages from the ET itself (24.1±1.9 and 24.3±1.8 ka) and the distinct peak of volcanic minerals in the Dehner maar around 24.3 ka (cf. Fig. 34, Römer et al., 95

96 | STUDY 2: The Eltville Tephra (Western Europe) age revised

2016). Therefore, we suggest the ET age lie between 1σ uncertainties of the ages above and below the ET, between 25.6 and 23.2 ka. This age is fully consistent with error margins of luminescence ages from the ET itself and the age model of the Dehner maar core (cf. Sirocko et al., 2016).

All methods require at least some data which are located directly above or below the horizon in question. Generally, age estimates tend to become increasingly unreliable when the distance between the sample and the horizon in question increases. However, random uncertainty poses a further problem. Even the use of dates from samples that have been taken exactly from above and below a stratigraphical marker bed is prone to the phenomenon of random uncertainty. Random uncertainty tends to produce numerous ages. These ages may be inconsistent with the stratigraphic concept of superposition, and may indicate non existing age inversions. Whether the uncertainty represented by 1-or 2σ uncertainty represents more complex probability density functions properly, remains a matter of debate.

Outliers in the input data may influence the results. If input data are systematically over- or underestimated (as some luminescence datasets indicate; cf. Timar-Gabor et al., 2011; Lomax et al., 2012), results of any data compilation will have the same problem. The Bayesian approach applied has a high resolution using the employed data set, and calculation uncertainty is negligible as shown in Tab. 5.

Fig. 33: Probability density functions for 200.000 runs from samples above (grey) and below (white) the ET. Diamonds show the ages generated directly from the ET (sample RGE-4). The combination of statistical parameters for both density functions facing the ET, interlayered between these, lead to depositional periods for the ET with specific uncertainties. Median: 22.0 - 26.8 ka; 1σ: 22.5 - 26.2 ka, 2σ: 24.3 – 24.4 ka. The 1σ uncertainty of the luminescence ages from Ringen are in accordance with the 1σ uncertainty of the modelling results. STUDY 2: The Eltville Tephra (Western Europe) age revised | 97

5.5.2 Chronological, palaeoenvironmental and stratigraphical implications Fig. 34 shows a compilation of different archives which can be linked by the ET. Each archive provides specific information concerning environmental and climatic condition which can be combined and discussed by the revised age of the ET. Starting with the role of the ET in the context of the Quaternary Eifel Volcanic Fields, the discussion will lead over to the importance as chronostratigraphic marker for loess stratigraphies and their correlation to Greenland ice core data and the Eifel Laminated Sediment Archive.

Fig. 34: Comparison and correlation of different archives and proxy data connected to the ET as chronostratigraphic marker. Legend as in Fig. 31, including the Kesselt Layer occurring in the European loess belt from Northern France towards the Lower Rhine Embayment. The E4/NC was correlated to the GI-2 as discussed in the text. The E2 soil was correlated by Antoine et al. (2009) and Moine (2014) to the GI-3 and 4. The median, 1σ and 2σ calculation results are visualized by probability density functions (cf. Fig. 33). Tephra layers found in Eifel maar lakes are mentioned as a tephra chronological framework. UMT: Ulmener maar Tephra 11,000 b2k (Förster and Sirocko, 2016); LST: Laacher See Tephra 12,900 b2k (Bogaard, 1995; Baales et al., 2002); ET: Eltville Tephra (luminescence ages of this study); MM & AV: Tephra found in the Meerfelder maar and barrier lake of the Alf Valley (Velde, 1988 cited in Haverkamp and Beuker, 1993; Pirrung et al., 2007); WBT: Wartgesberg Tephra (Förster and Sirocko, 2016); WBLF: Wartgesberg lava flow (Mertz et al., 2015); UT1: Unknown Tephra 1 (Förster and Sirocko, 2016). The content of volcanic minerals from the Dehner maar (DE3 core) is shown as an indicator for the occurrence of crypto tephra (Römer et al., 2016). The ELSA vegetation (Sirocko et al., 2016) and flood stacks (Brunck 97

98 | STUDY 2: The Eltville Tephra (Western Europe) age revised

et al., 2016) are displayed as important regional proxy data for environmental reconstructions. In addition to Fig. 31, the subdivision of the GS-3 according to sea surface temperatures (SST) for the north-eastern Atlantic (NEA) was added (Austin et al., 2012).

5.5.2.1 The ET in the context of the Quaternary Eifel Volcanic Fields The ELSA tephra stack provides a tephra chronological framework of visible ash layers for the correlation of Eifel maar drill cores. The UPG sediments in the ELSA-tephra stack contain the Unknown Tephra 1 (30.2 ± 2.0 ka) and the Wartgesberg Tephra (27.9 ± 2.0 ka). These tephras have been dated by ice core tuning to NGRIP (Förster and Sirocko, 2016). The ELSA stack lacks any tephra layer corresponding to the previously supposed eruption of the ET (20- 23 ka) and the revised age of this study. However, tephra can also be incorporated in sediments without being visible (cryptotephra). The transparent heavy mineral content of the Dehner maar core show that volcanic minerals, particularly clinopyroxene, are strongly increased from the Wartgesberg Tephra (42 %) upwards to 25.2 ka with a separated strong peak of 40 % around 24.3 ka followed by a sharp decrease towards constant background values (Fig. 34). This may be interpreted as a hint for the presence of a cryptotephra or the incorporation of older tephra deflated from the surroundings. However, the peak is an excellent agreement with the modelled and direct ages of the ET supporting the assumption of a cryptotephra.

These observations are in agreement with several primary and relocated tephra layers clustered in the Meerfelder maar (Negendank et al., 1990) and in the sediments of the barrier lake of the Alf Valley formed after the eruption of the Wartgesberg volcano (Pirrung et al., 2007). Within the barrier lake, several primary and reworked tephras were found 4 m above the closest 14C age of 27.0 ± 0.6 ka cal. BP (Pirrung et al. 2007; Danzeglocke et al., 2007). Pirrung et al. (2007) correlated their tephra to a 40-50 cm thick tephra within the Meerfelder maar at 38.5 m, which is also surrounded by several thin additional reworked and primary tephra layers (Negendank et al., 1990). This tephra was dated by varve chronology to ~35 ka (Negendank et al., 1990, and references therein), 25.7 ka by palaeomagnetism (Haverkamp and Beuker, 1993) and the sediments directly below by TL to ~25 ka (Velde, 1988, citied in Haverkamp and Beuker, 1993, no uncertainty mentioned). Both tephras could represent possible equivalents of the ET.

The peak in the volcanic minerals of the Dehner maar and the presence of tephras in the barrier lake of the Alf valley and Meerfelder maar would be the first evidence for a possible correlation between the ET found in loess sections and tephras found in sediments of the Eifel maars (Fig. 34).

STUDY 2: The Eltville Tephra (Western Europe) age revised | 99

5.5.2.2 Event-based correlations Palaeosols and grain sizes of loess profiles were frequently correlated to Greenland interstadials, especially for the UPG (cf. Antoine et al., 2009; Kadereit et al., 2013; Haesaerts et al., 2016; Schirmer, 2016). The revised age of the ET (modelling and direct dating) found in loess sections is strengthened by the distinct peak of volcanic minerals in the Dehner maar core (Fig. 31). The accordance between both archives promotes the reliability of event-based correlations to Greenland ice core data, where the ELSA stacks were tuned to.

The revised age of the ET (1σ, 23.2-25.6 ka) covers a period of strong aeolian activity in the Northern Hemisphere (dust peaks of the GS-3, Fig. 31). Antoine et al. (2009, 2013) suggested that such phases can be found in loess sections of Europe by correlating fine sand content, median and the pattern of the grain size index (GSI; Rousseau et al., 2007). At Nussloch, they found the ET in a sediment package (unit 34) which is characterised by local maxima in the fine sand fraction and GSI. The same observation were made for the loess record Hecklingen in the forelands of the Harz-Mountains (Krauß et al., 2016). Mollusc data (Moine, 2014) from several loess sections in central Europe and δ13C from Nussloch (Hatté et al., 1998) also indicate strong aridity during the deposition.

Field observations from several loess sections surrounding the Eifel Mountains confirm strong aeolian activity during the time of ET deposition. The thickness of the ET sequence (tephra and loess) can vary between 1 and 20 cm according to the distance to the Eifel mountains and the geomorphological setting (e.g. Löhr and Brunnacker, 1974; Bibus and Semmel, 1977; Meijs et al., 1983; Löhr, 1987). After the eruption, the aeolian activity was still strong which can be seen by the increasing value of the GSI and fine sands from Nussloch and the occurrence of ~ 2.5 m of loess between the ET and Kesselt layer from Vroenhoven East (Meijs et al., 1983). The eruption and deposition of volcanic ashes are, in contrast to (dis)continuous loess deposition, temporary closed events usually lasting days to weeks. Therefore, the ET sequence demonstrates that thick loess accumulation (up to 20 cm) can occur very rapidly, especially if strong wind dynamics such as dust storms predominate. During the ET deposition, a low pressure system coming from the west is the most likely explanation for the spatial distribution and local variation of thicknesses. The observation is in good accordance with the conceptual model for loess deposition in Western Europe which is supposed to be controlled by storm tracks running in W-NW direction from the Atlantic (Antoine et al., 2009; Sima et al., 2009).

The revised ET age lies between the GI-2 and GI-3. Interstadials of the UPG are supposed to lead to cryosol formation in Western and Central Europe (Antoine et al., 2009, 2013). The two-folded, intensively bleached E2 soil was correlated in the past to the GI-3 and 4 (e.g. Antoine et al., 2009, 2013; Moine, 2014). The very weak E3 soil could not be attributed to a Greenland interstadial. Austin et al. (2012) have shown that not every climate warming occurring in Europe must also be recorded in Greenland ice. They studied three marine drill 99

100 | STUDY 2: The Eltville Tephra (Western Europe) age revised

cores from the north-eastern Atlantic and found an additional short-time interstadial period lasting from 24.8 to 25.6 ka according to increased sea surface temperatures. This warming could be responsible for the E3 soil in loess sections, which is situated slightly below the ET (Fig. 31: Simplified and generalized loess stratigraphy for the last glacial cycle in Western and Central Europe with the position of the ET modified according to Schönhals et al. (1964), Bibus (2002) and Haesaerts et al. (2016). The luminescence ages around the ET show wide scattering. LG abbreviates Late Glacial. The NGRIP δ18O and dust content and ice core data (Andersen et al., 2006; Vinther et al., 2006; Rasmussen et al., 2006, 2008, 2014; Svensson et al., 2006, Wolff et al., 2010; Blockley et al., 2012; Seierstad et al., 2014) are plotted as an accurate and independent timescale for the comparison with luminescence ages and represent an additional important climate record of the northern hemisphere during the Last Glacial cycle. GI abbreviates Greenland interstadial and GS Greenland stadial. The Lohne Soil formation has been correlated to the Greenland Interstadials 5 to 8 as a demarcation of the MPG/UPG transition. The precise timing is still under discussion (cf. Antoine et al., 2009; Rousseau et al., 2011; Kadereit et al., 2013, Kadereit and Wagner, 2014; Sauer et al., 2016).).

An intensive erosion event (Eben Unconformity) ends the strong accumulation period from Northern France towards the Lower Rhine Embayment. It is deeply incised into the underlying sediments and preforms the recent topography. At some sections, it shows frost cracks reaching down into the niveo-aeolian loess which indicates dryness and strong temperature amplitudes (cf. Van Vliet Lanoe, 1989, 1998). The frost cracks were later filled with the reworked sediments of the Kesselt layer. The base is marked by laminated sand and coarse silt with wind polished gravels (Schirmer, 2003, 2016). Such phenomena were also reported for imbedded Palaeolithic artefacts from Belgium and the Netherlands (Meijs, 2002) and the opencast lignite mine Garzweiler (Kels and Schirmer, 2010). However, Schirmer (2016) documented that homogenous, calcareous loess was mixed with reworked decalcified loess and soil sediments. Soils with increased clay content are hardly erodible by wind (Pye, 1995). Therefore, an interplay of deflation and run-off processes (e.g. slope wash) could be responsible for the Eben unconformity. The extreme weather events recorded in the ELSA flood stack (Brunck et al., 2016) between 23-24 ka confirm the additional role of fluvial erosion (Fig. 34). The moisture could have been delivered from the Atlantic, where Austin et al. (2012) recorded short time warming events of the SST in marine drill cores during the NEA-GS 3a which could have promoted moisture supply towards Western and central Europe. The basal frost cracks however show that deflation seems to be the initial process.

The E4 soil is situated stratigraphically above the ET and represents the Phase A/B transition. This boundary, at least the loess above, was dated to 20-23 ka (Van den Haute et al., 1998; Antoine et al., 2003; Kreutzer et al., 2012a; Meszner et al., 2013; Moine, 2014) and correlated to the GI-2 (Antoine et al., 2009; Schirmer, 2016). The revised age of the ET confirms this correlation. The E4 soil is the most developed cryosol of the UPG although solar insolation reached a minimum. The strongly solifluidal tongued lower part indicates, that the STUDY 2: The Eltville Tephra (Western Europe) age revised | 101 moisture was still increased. By the end of the GI-2, the loess facies changed from niveo- aeolian in a tundra environment towards homogenous loess in a dry and cold polar desert (Fig. 34).

Due to stratigraphic evidence, the revised ET age strengthened these correlations, if the assumption is accepted that climatic events in Greenland and Europe occur (semi)time- synchronous. In this case, the temporal overlaps between interstadials and calculated deposition time of the ET could be excluded. Through event-based correlations, the deposition could have taken place between the GI-2.2 and NEA-GS 3b or rather the NEA-GS 3a (~23.4-24.8 ka; Fig. 34). This in good agreement with the 2σ age (24.3-24.4 ka), direct ages from the ET (24.3 ± 1.9 and 24.1 ± 1.8 ka) and the peak of volcanic minerals in the Dehner maar core (~24.3 ka). However, due to the uncertainty of the individual chronologies, this refined age range should be treated with caution.

5.6 Conclusions This study uses Bayesian resampling statistics to integrate ages constraining the deposition of the ET from sediment above and below the unit, which is an important marker bed of the Weichselian Upper Pleniglacial in Western and central Europe. Published luminescence ages (n=83) were screened for the most reliable ages which have to fulfil the quality criteria (i) measured with the SAR-protocol and (ii) tests and correction for anomalous fading for polymineral K-feldspar rich samples. The dataset was extended by four new luminescence ages (quartz and pIRIR290) bracketing the ET from the loess section Romont (Belgium). The final dataset of 5 ages above and 7 ages below the ET were combined to an age range from 23.2-25.6 ka. Though of the scattering of individual ages with frequent age inversions, the scatter between every modelling run (n=10,000) is extremely low (standard deviation = 40 yrs), and hence highly reproducible. The revised age range is in perfect agreement with new luminescence ages generated directly from the ET at the loess-palaeosol sequence Ringen yielding ages of 24.3 ± 1.8 ka (pIRIR290) and 24.1 ± 1.9 ka (quartz). They correspond with a separable peak in the volcanic mineral content of the Dehner maar drill core (Eifel Mountains) around 24.3 ka, which can be interpreted as a hint for a cryptotephra. Both results can be correlated to tephras found in the Meerfelder maar and the barrier lake of the Alf Valley (~25- 26 ka). This implies for the first time a possible equivalent of the ET in the sediments of the Eifel maar lakes.

The revised age enable more reliable event-based correlations between loess-palaeosol sequences and other climate proxies such as the Eifel Laminated Sediment Archive and Greenland ice core data for the Weichselian Upper Pleniglacial, a phase of strong environmental dynamics and climatic turnovers. We propose a correlation and a chronological model for the sediments surrounding the ET. The integration of stratigraphic evidences due to event-based correlations may again refine a modelled age. 101

102 | STUDY 2: The Eltville Tephra (Western Europe) age revised

The introduced method of combing luminescence ages from different localities to determine a reliable and reproducible age of a marker bed may be applied to further units of loess sections and other archives. Differences in sedimentation rates dependent on the interplay of topography, exposition and prevalent wind directions hampers the possibility to date a marker bed as precise as possible at a single section (see scattering of dates in Fig. 31Fig. 31: Simplified and generalized loess stratigraphy for the last glacial cycle in Western and Central Europe with the position of the ET modified according to Schönhals et al. (1964), Bibus (2002) and Haesaerts et al. (2016). The luminescence ages around the ET show wide scattering. LG abbreviates Late Glacial. The NGRIP δ18O and dust content and ice core data (Andersen et al., 2006; Vinther et al., 2006; Rasmussen et al., 2006, 2008, 2014; Svensson et al., 2006, Wolff et al., 2010; Blockley et al., 2012; Seierstad et al., 2014) are plotted as an accurate and independent timescale for the comparison with luminescence ages and represent an additional important climate record of the northern hemisphere during the Last Glacial cycle. GI abbreviates Greenland interstadial and GS Greenland stadial. The Lohne Soil formation has been correlated to the Greenland Interstadials 5 to 8 as a demarcation of the MPG/UPG transition. The precise timing is still under discussion (cf. Antoine et al., 2009; Rousseau et al., 2011; Kadereit et al., 2013, Kadereit and Wagner, 2014; Sauer et al., 2016).) However, every dataset has to be screened for the most robust ages for calculations to reduce the potential of systematic age shifts as a function of different measurement setups. Against this background, the attempt to combine ages from different localities is a practical way to reduce scatter in data, which can originate from the methods itself, but also from the geomorphological setting before, during and after the deposition of a marker bed. STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 103

6 OSL chronologies of palaeoenvironmental dynamics recorded by loess-palaeosol sequences from Europe: Case studies from the Rhine-Meuse area and the Neckar Basin

Joerg Zens a, Philipp Schulte a, Nicole Klasenb, Lydia Kraußa, Stéphane Pirsonc, Christoph b b e a a d Burow , Dominik Brill , Eileen Eckmeier , Holger Kels , Christian Zeeden , Paul Spagna , Frank Lehmkuhla a Department of Geography, RWTH Aachen University, Templergraben 55, 52056 Aachen, Germany b Institute of Geography, University of Cologne, Albertus-Magnus-Platz, D-50923 Cologne c Direction de l’archéologie, Service public de Wallonie, Rue des Brigades d'Irlande, 1, B-5100 Jambes, Belgium d Earth and Life History Operational Division, Royal Belgian Institute of Natural Sciences, Vautier Street, 29, B-1000 Brussels, Belgium e Department of Geography, Ludwig-Maximilians-University Munich, Luisenstraße 37, D-80333 Munich

Published 2017 in the special issue “Eurasian Loess records: missing link to a better understanding of Northern hemisphere Pleistocene climate evolution” of Palaeogeography, Palaeoclimatology, Palaeoecology

Abstract

Loess-palaeosol sequences (LPS) represent an important terrestrial archive for the reconstruction of the palaeoenvironmental evolution during the Last Glacial cycle in Europe. In the Rhine-Meuse area and the southwestern Germany, there are only few numerical ages determined with state-of-the-art luminescence methods, which limits the robustness of established chronostratigraphies. This study presents a comparative dating approach using quartz and feldspar post-infrared (pIRIR290) optically stimulated luminescence (OSL) from fine- and medium-grained samples of five loess-palaeosol sequences. Palaeoenvironmental dynamics are reconstructed by high-resolution grain-size analysis.

103

104 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

The OSL ages are evaluated as being robust and consistent with other records. Furthermore, we show that ages for hillslope deposits are sometimes overestimated due to low-frequency high-magnitude erosive processes. The integration of OSL ages, stratigraphy and high-resolution grain-size data contributes to a temporal more complete data record from Western and Central Europe. Secondly, we propose a combined stratigraphic model for LPS of the Last Glacial cycle, which is developed and discussed in the context of other key sites such as Havrincourt, Schwalbenberg II, Tönchesberg, Nussloch and Dolni Vĕstonice. Comparable chronologies and patterns in proxy data between sites with a large spatial distance suggest a possible semi-synchronous response to climatic changes in Europe. By combining our data with the Eifel-Laminated-Sediment-Archive (ELSA) and the NGRIP ice core, a relationship of loess archives and large-scale climatic signals is discussed and a proxydata based event-stratigraphy is developed. This model refine existing chronostratigraphic models and contributes to solve open discussion concerning the timing and demarcation of sedimentary units and sequences from for Western and Central Europe.

6.1. Introduction Loess-palaeosol sequences (LPS) are sensitive archives for palaeoenvironmental reconstructions of the Late Pleistocene in Western and Central Europe. Due to discontinuous loess sedimentation and frequent phases of erosion often found in a periglacial environment, the temporal resolution of LPS is influenced by their geomorphological setting (Lehmkuhl et al., 2016). In an ongoing effort scientists have identified characteristic sedimentary sequences, or marker beds (e.g. palaeosols and tephra layers), that allow for a comprehensive inference of past climate sub stages of the Last Glacial cycle (e.g. Schönhals et al., 1964; Semmel, 1968). Drawing on these observations, idealised regional chrono-, pedo- and lithostratigraphic schemes were developed (e.g. Semmel, 1968; Antoine et al., 2016; Haesaerts et al., 2016; Lehmkuhl et al., 2016; Schirmer, 2016).

The chronologies of these schemes are often based on luminescence dating. It is a method to date the burial age of sedimentary grains (e.g. quartz and feldspar) and has thus been frequently applied to LPS from Western and Central Europe since the 1980s. The majority of ages is based on thermoluminescence (TL) and infrared-stimulated luminescence (IRSL) dating of fine-grained polymineral samples using multiple aliquot protocols without correction for anomalous fading (e.g. Wintle and Brunnacker, 1982; Zöller et al., 1988; Henze, 1998; Van den Haute et al., 1998, 2003; Frechen et al., 2001; Lang et al., 2003; Bibus et al., 2007; Frechen and Schirmer, 2011). Anomalous fading describes an unwanted signal loss during laboratory measurements of feldspars, which lead to an age underestimation of the true burial age (Wintle, 1973) and hence it is a known shortcoming of feldspar dating (Roberts, 2008). Nevertheless, previous stratigraphic models rely on these ages. STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 105

The development of the single aliquot regenerative protocol (SAR, Murray and Wintle, 2000, 2003), correction factors for anomalous fading (Huntley and Lamothe, 2001; Auclair et al., 2003; Kars et al., 2008) and the detection of less/non fading post-infrared feldspar signals measured at elevated temperatures (pIRIR, Thomsen et al., 2008; Stevens et al., 2011; Thiel et al., 2011a) considerably improved the accuracy and precision of luminescence dating. Several studies were conducted applying these state-of-the-art methods (Fig. 35), but only a few of them provided more comprehensive chronologies (e.g. Tönchesberg, Schmidt et al., 2011a; Ostrau, Kreutzer et al., 2012a; Seilitz, Meszner et al., 2013; Dolni Vĕstonice, Fuchs et al., 2013; Havrincourt, Antoine et al., 2014; Gleina, Zech et al., 2017). The majority presented only some single ages (e.g. Nussloch, Tissoux et al., 2010, Gocke et al., 2014; Schwalbenberg II, Frechen and Schirmer, 2011; Gaul/Weilbach, Schmidt et al., 2011b; Ariendorf, Schmidt et al., 2014; Muenzenberg; Steup and Fuchs, 2017) or were focused on specific marker beds and time slices (e.g. Lower Austria, Thiel et al., 2011b; Krems-Wachtberg, Lomax et al., 2012; Grub- Kranawetberg, Zöller et al., 2013; Datthausen, Sauer et al., 2016; Romont and Ringen, Zens et al., 2017). Consequently, the amount of more reliable OSL ages is limited to improve the existing chronostratigraphy and event-stratigraphies integrating other climatic archives (e.g. Greenland ice cores).

In consequence of these shortcomings, this study aims to develop robust OSL chronologies for LPS from the Rhine-Meuse area and southwestern Germany (Fig. 35, Romont, Garzweiler,

Ringen and Frankenbach) by comparative quartz OSL and pIRIR290 dating. Grain-size analysis is used to reconstruct palaeoenvironmental dynamics and to investigate if specific time slices and sedimentary units have characteristic and comparable grain-size signatures. Such signatures are used as a further stratigraphic tool. Geochemical analysis (X-ray fluorescence and CaCO3) is used to investigate sedimentary properties and in combination with portable OSL data helps to investigate problematic samples. Based on results of stratigraphy, OSL dating, grain size and geochemical analysis we develop a comprehensive stratigraphic model, which we link to proxy data derived from the Eifel Laminated Sediment Archive (ELSA, Sirocko, 2016) and Greenland ice cores (e.g. Rasmussen et al., 2014).

105

106 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

Fig. 35: Location of the investigated loess-palaeosol sequences (red dots) in the European loess belt. Black dots show selected loess sections with OSL chronologies based on single-aliquot protocols and if feldspar is used as dosimeter, correction for anomalous fading. The black star shows the Dehner maar (DM), which is an important archive of aeolian dynamics (Seelos et al., 2009; Römer et al., 2016). Loess distribution modified according to Haase et al. (2007). Maximum extent of the Weichselian glaciation according to Ehlers et al. (2004, 2011). Hav: Havrincourt (Antoine et al., 2014); Rom: Romont West and East; Garz: Garzweiler (this study and Fischer et al., 2012); HWB: Hohlweg Butzheim (Fischer, 2010); Rge: Ringen; RS: Remagen-Schwalbenberg II (Frechen and Schirmer, 2011; Klasen et al., 2015); Ari: Ariendorf (Schmidt et al., 2014); Töc: Tönchesberg (Schmidt et al., 2011a); Gau: Gaul/Weilbach (Schmidt et al., 2011b); Mue: Muenzenberg (Steup and Fuchs, 2017); Nus: Nussloch (Tissoux et al., 2010; Gocke et al., 2014); Fb: Frankenbach; Dat: Datthausen (Sauer et al., 2016); Ost: Ostrau (Kreutzer et al., 2012a); Sel: Seilitz (Meszner et al., 2013); Gle: Gleina (Zech et al., 2017); Str: Stratzing (Thiel et al., 2011a); KW: Krems-Wachtberg (Lomax et al., 2012; Zöller et al., 2014); GK: Grub-Kranawetberg (Zöller et al., 2013); DV: Dolni Vĕstonice (Fuchs et al., 2013).

6.2 Stratigraphic and chronological framework of Western and Central European loess Several loess stratigraphies based on palaeosols and specific sedimentary units were developed since the 1950s for the sub areas of the European loess belt. Latest updates for the northwestern part with focus on the Last Glacial cycle were recently introduced for Belgium STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 107 by Haesaerts et al. (2016) and the Lower Rhine Embayment by Schirmer (2016) (Fig. 36). These schemes were compared with loess records and stratigraphies from Northern France (Fig. 36, Antoine et al., 2016), Central Germany and the northern foreland of the Harz Mountains (Lehmkuhl et al., 2016; Krauß et al., 2016). Numerical age information obtained from luminescence and radiocarbon dating were used to established chronological frameworks and to propose event-stratigraphies by correlating sedimentary units to Greenland ice core data (Fig. 36, Rasmussen et al., 2014).

The compiled chronologies are the result of combining various dating techniques. Average ages were calculated by radiocarbon, TL on heated flints, TL, IRSL and quartz OSL dating results from numerous sites from Northern France (cf. Antoine et al., 2016 and references therein). The Havrincourt site provides a reliable high-resolution quartz OSL chronology for the MPG and LPG (Antoine et al., 2014). The numerical chronology of the Belgium and the Lower Rhine Embayment are dominated by radiocarbon, TL and IRSL dating (multiple aliquots, no fading correction) from Harmignies (Haine Basin, Frechen et al., 2001) and Schwalbenberg II (Middle Rhine, Frechen and Schirmer, 2011). From the latter one, a few pIRIR225 and fading corrected feldspar ages exist (Frechen and Schirmer, 2011), but were not considered for the chronostratigraphic framework by Schirmer (2016). The Eemian and Early Glacial chronology was supplemented by some quartz OSL and isothermal thermoluminescence ages from the opencast lignite mining Garzweiler (Fischer et al., 2012). The heterogeneous database of the chronologies results in the disagreement in the correlation of palaeosols and climatic stages to Greenland ice core data between the different schemes (Fig. 36).

Stratigraphically, the Eemian interglacial is represented by a truncated leached Bt horizon of a former Luvisol. After Antoine et al. (2016), the Early Glacial (EG) is divided into two substages of distinct soil formations defined as grey forested soil phase (Bth, grey-forest soil, Greyzem) and steppe soil phase (Ah, Chernozem-like humic soil) (Fig. 36). Both phases reflect a transition from interglacial towards colder and more continental climate conditions (e.g. Semmel, 1998; Haesaerts et al., 2016; Schirmer, 2016). They are traceable from Northern France towards the Ukraine and show a complex genetic history (cf. Haesaerts and Mestdagh, 2000; Antoine et al., 2013; Haesaerts et al., 2016). Due to their wide distribution they form a soil complex that serves as an important marker unit of the Last Glacial cycle. In Belgium, the humic soil complex is further characterized by the incorporated Rocourt Tephra (Juvigné et al., 2008; Pouclet et al., 2008).The deposition was assumed to have taken place during the GI- 21 by correlating pedostratigraphic units to the Grande Pile pollen profile and the GRIP ice core (Juvigné et al., 2013).

The Lower Pleniglacial (LPG) is the first phase of glacial loess deposition during the Weichselian Pleniglacial (Haesaerts and Mestdagh, 2000). The EG/LPG transition is characterized by slope wash erosion and redeposition as heterogeneous, finely laminated

107

108 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

colluvium. It is followed by brownish silts (Havrincourt brown silts) addressed as brown boreal soil (Malplaquet Soil) in Belgium or as Regosol-Cambisol (Jackerath Soil) in the Lower Rhine Embayment, which is developed in loess. The subsequently deposited loess package contains several thin and weakly developed tundra gleys and humic soils (Fig. 36).

The Middle Pleniglacial (MPG) is characterized by the formation of different interstadial soils with varying intensities and pedogenetic features. Loess deposition was strongly diminished (Antoine et al., 2001) and frequent phases of erosion reduced the resolution of MPG sediments in most LPS (Antoine et al., 2001). Consequently, the correlation of palaeosols from different areas concerning this phase is difficult and the precise correlation to Greenland interstadials remains challenging (cf. Antoine et al., 2009; Kadereit et al., 2013; Sauer et al., 2016).

The Upper Pleniglacial (UPG) exhibits the highest loess accumulation rates of the entire Last Glacial cycle and can be divided into two sedimentary facies: the niveo-aeolian (cold- humid) and the homogenous loess (cold-arid). They were termed Hesbaye and Brabant loess in Belgium and the Lower Rhine Embayment (cf. Haesaerts et al., 2016; Schirmer, 2016). Here, the terms UPGa and UPGb according to Zens et al. (2017) and Lehmkuhl et al. (2016) are used. The niveo-aeolian loess is characterized by the highest accumulation rates of the Last Glacial cycle (e.g. Frechen et al., 2003). It contains several tundra gleys and the Eltville Tephra (Pouclet and Juvigne, 2009; Zens et al., 2017). The homogenous UPGb loess starts above an unconformity with the formation of the most developed palaeosol (Nagelbeek Complex/E4 Soil) of the UPG (Schirmer, 2003, 2016; Haesaerts et al., 2016). It is an important marker horizon because it is continuously traceable in the Western and Central European loess province (Pouclet and Juvigne, 2009; Krauß et al., 2016; Zens et al., 2017). The UPGb loess that covers the Rhine-Meuse area has a continuous thickness 2 to 6 m (cf. Henze, 1998; Meijs, 2002; Antoine et al., 2003; Kels, 2007). STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 109

Fig. 36: Compilation of simplified stratigraphic schemes and absolute chronologies from Northern France (Antoine et al., 2016), Belgium (Haesaerts et al., 2016) and the Lower Rhine Embayment (Schirmer, 2016) and their correlation to Greenland interstadials (GI) of the NGRIP ice core (50 yrs average, Rasmussen et al., 2014; Seierstad et al., 2014). The correlation is based on numerical dating (radiocarbon and luminescence) and pedostratigraphy. They are structured by five sub stages according to Zagwijn and Paepe (1968) which are characterized by homogenous large scale climatic conditions. The most important generations of ice wedges are also mentioned for Northern France and Belgium, whereas for the Lower Rhine Embayment comprehensive observations are missing. The grey and white fields show the temporal demarcation of the major stages. The hatching at the NGRIP curve highlights periods where the schemes do not agree. The dotted lines show correlations of single units which are confirmed by the stratigraphic position. NTH: Nagelbeek Tongued Horizons; RHH: Riemst Humic Horizon; M-C: Maisisères-Canal humic horizons; HCR: Humiferous complex of Remicourt; RT: Rocourt Tephra; VSG: Villers-St-Ghislain; NEZ: Niedereschbach zone; H.S.: humus zone; E1-3: Erbenheim Soils. For the legend of units, see see Fig. 37.

109

110 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

6.3 Regional setting and study sites The LPS Romont (Rom), Garzweiler (Garz) and Ringen (Rge) are located in the Rhine- Meuse area (Fig. 35). The topographic setting is dominated by vast plains with incised valleys of Rhine and Meuse and their tributaries (e.g. Rur, Erft). The plains gradually turn into an undulating transition zone towards the low mountain range of the Rhenish Massif. As a part of the European loess belt, loess is extensively distributed and can reach thicknesses of 15-20 m in favourable geomorphological settings (e.g. Schirmer, 2002, 2012; Kels, 2007; Haesaerts et al., 2016). The loess cover decreases towards a transition zone in the North where it gradually changes to sandy loess and cover sands (e.g. Poser, 1951). Aeolian sediments originated from the braided-river system of Rhine and Meuse (Smalley et al., 2009; Lehmkuhl et al., 2016) and the dried out shelves of the Channel and North Sea (Smykatz-Kloss, 2003; Antoine et al., 2009). In addition, the frequent reworking of older loess sediments by deflation (Razi Rad, 1976; Henze, 1998) and the incising tributaries from the Eifel Mountains were further important contributors (Janus, 1988). The oldest sedimentary units where dated to the marine isotopic stage (MIS) 11 based on pedostratigraphy (Meijs, 2002; Schirmer, 2002; Meijs et al., 2013).

The LPS Frankenbach (FB) is situated in the border zone of the eastern Kraichgau region and northwestern Neckar Basin in southwestern Germany (Fig. 35). The undulating landscape is dominated by dry valleys and incised tributaries of the Neckar River. The area is structured by a tectonic depression which is filled with thick packages of Pleistocene gravels and sands of the Neckar and with subsequently deposited loess sediments (Bibus et al., 2008). Eitel (1989) suggested that the braided-river system of the Rhine was the main source for aeolian deposits according to a decreasing grain-size trend towards the Kraichgau. In the previously documented loess records of Böckingen and Frankenbach (e.g. Bibus, 2002; Bibus et al., 2008), up to four fossil interglacial soils were observed indicating a possible temporal resolution back to MIS 11.

6.3.1 Romont West and East The chalk quarry C.B.R. Romont is located between the villages of Bassenge and Eben- Emael 5 km south of Maastricht (Fig. 35). Here, Meuse terraces and Pleistocene loess covers a steep hill that consists of Oligocene marine sands and Cretaceous chalk stone. The hill was excavated during mining activities (Juvigné, 1992). The Romont sequence is the type locality of the Eben-Zone sensu Schirmer (2003) (cf. Fig. 36) and was recently defined as the new loess stratotype in Belgium (Haesaerts et al., 2011). Further studies focused on the Early Glacial Chernozem-like humic soils and the embedded Rocourt Tephra for which Romont also serves as stratotype (Juvigné et al., 2008). First OSL ages were presented for the sediments surrounding the Eltville Tephra by Zens et al. (2017). The samples RMT2_6 and RMT2_7 are integrated in this study. STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 111

The new loess section Romont West (50.791319° N; 5.644245° E, 100 m asl) is situated on a north-western exposed bottom slope. It is composed of four consecutive profiles with an overall thickness of ~11 m (Fig. 37). The base of the section is characterized by Saalian loess with an intercalated tundra gley. The Rocourt pedocomplex is covered by a humic soil complex with two separable units (Humiferous Complex of Remicourt, HCR) and the incorporated Rocourt Tephra (Fig. 38A). The LPG sediments consist of ~ 4 m finely laminated colluvium with intercalated soil pellets interrupted by a phase of aeolian input in which a weak brown boreal soil (Malplaquet Soil, MP) and a greyish humic soil (Kincamp A and/or B Soil, KC A/B) are developed (Fig. 38A and E). In the upper part, crotovinas occur and some penetrate the boundary between the humic soil (filled with light-brownish loess) and the colluvium indicating again erosion in this part of the sequence (Fig. 38F). At the top of the laminated colluvium, reddish-brown sediment with bio galleries and subordinated manganese and iron precipitation may be indicative for a palaeosol (Les Vaux Soil?, LV, Fig. 38E). Bleached and laminated loess follows above with an intercalated bleached tundra gley with manganese and iron precipitation and in which many molluscs were found (Harveng Soil?, HV). The Eben Unconformity (EU) is less pronounced but seems to cut the tundra gley and merges into the strongly cryoturbated Kesselt Layer (KL) and Nagelbeek Complex (NC). UPGb loess covers the complex and provided the source material for the Holocene soil formation.

The new profile Romont East (50.785689° N; 5.657475° E, 108 m asl) is situated on an eastern exposed convex slope. The thickness reaches 7 m (Fig. 37). At the base, two palaeosols are developed and divided by an unconformity. The lower soil has a reddish-brown colour with manganese concretions (ø 1 mm) and a fine platy structure. Clay coatings are visible as well as bleached spots with ferruginous rims. These elements point to an interglacial or early glacial luvisol-like soil, degraded due to an increasing acidification at the end of the climatic cycle. This soil composition is typical for the Rocourt pedocomplex (e.g. Haesaerts et al., 2016). The red-orange upper soil is strongly cryoturbated and mixed with an overlying tundra gley and shows manganese precipitation. At the top of the tundra gley, frost cracks are developed. Another very thin tundra gley follows separated by few centimetres of loess. Above, niveo- aeolian loess of the UPGa follows with the embedded Eltville Tephra (ET). It has an average thickness of 3 mm and is disturbed by cryoturbation. Above the Eben Unconformity, the Kesselt Layer contains some small gravel (< 5 mm) at the base in separated pockets. The overlying Nagelbeek Complex is bipartite and solifluidal mixed with the underlying Kesselt Layer. The lower part is more brownish grey with iron precipitation while the upper part is light greyish with less iron precipitation. The Nagelbeek Complex is covered with homogenous loess of the UPGb. A large ice wedge reaches down from the recent soil into the underlying loess.

111

112 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

6.3.2 Ringen The clay pit Ringen is located close to the villages Ringen and Grafschaft 17 km south of Bonn on the southern slope of the Ringener stream valley (Fig. 35). Oligocene and Miocene clays are dipping to NE with an inclination of 10-15° and are covered by up to 14.5 m of loess (Henze, 1998). Former studies focused on pedostratigraphy (Löhr and Brunnacker, 1974; Henze, 1998), mineralogical composition (Juvigné and Semmel, 1981; Pouclet and Juvigné, 2009) and luminescence dating of the Eltville Tephra (Juvigné and Wintle, 1988; Zens et al., 2017). The OSL sample RGE-4 presented in Zens et al. (2017) is also integrated in this study. Within the loess of the eastern exposed slope, a gyttia was developed, which was correlated to the Middle Pleniglacial based on pollen data by Henze (1998).

The newly documented loess section Ringen (50.570725° N; 7.111127° E, 174 m asl) is situated on a north-east exposed, slightly convex slope at a watershed position north of the gyttia. It is composed of four vertical consecutive profiles with an overall thickness of 9.2 m (Fig. 37). At the base, a former stream bed consisting of alternating gravel layers is incised into a dark greyish humic soil likely corresponding to the Early Glacial (Fig. 38G). An underlying interglacial soil was found in an adjacent profile (Fig. 38H). The humic soil has crotovinas filled with loess and root channels lined with manganese precipitation (Fig. 38D). The LPG sequence is divided through an unconformity that is characterized by a gravel layer (≤ 4 mm). The lower part consists of reworked soil sediments (Niedereschbach Zone, NEZ) with few crotovinas at the base and a weak boreal soil (BS1) on top. The upper part is build- up of slightly bleached loess also containing gravel-filled crotovinas. The base of the MPG sequences starts with slightly brown loess with further crotovinas. Above, the sequence is characterized by interstadial soils (BS2-4) of different intensities and a frost wedge cast reaching down from the base of the BS3. The UPG sediments show a finely laminated niveo- aeolian facies and contain four bleached tundra gleys (G1-4) and one intermediated tundra gley/boreal soil with a prismatic structure (BS5). The soils are accompanied by iron precipitation especially along small and thin root channels but also on aggregate surfaces. The Eltville Tephra is embedded in more homogenous loess and consists of five different bands separated by loess and an overall thickness of 3-5 cm. It is slightly disturbed by bioturbation (worm holes). A large ice wedge cast is developed from the truncated top soil and deeply penetrate the underlying loess.

6.3.3 Garzweiler-Borschemich The opencast lignite mine Garzweiler is located in the Lower Rhine Embayment westwards of the Erft River (Fig. 35). Several studies were conducted focusing on pedostratigraphy, sedimentology and partly on geochemistry (e.g. Henze, 1998; Schirmer, 2002; Kels, 2007; Fischer et al., 2012; Lehmkuhl et al., 2015). Only a few luminescence ages are published in the STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 113 literature that suggest the existence of unconformities often found in studies relying solely on lithostratigraphy (Henze, 1998; Fischer et al., 2012).

The loess section Garzweiler-Borschemich, further termed Garzweiler, (51.087305° N; 6.440433° E, 110 m asl) was located between the villages Holz and Borschemich prior to their excavation during lignite mining activity. It was situated on the top of a flat stretched slope with a southern exposure. The section mainly consists of UPGb loess overlying discordant older deposits of an unknown age (Fig. 37). The Eben-Zone is typically developed starting with the Eben Unconformity and the relocated, highly cryoturbated sediments of the Kesselt Layer. At its base, small gravels (< 1 cm) occurs. The cryoturbated Kesselt Layer was mixed with the overlying Erbenheim-4 Soil (E4) by solifluction. Above, several meters of homogenous loess with the intercalated Leonard Soil (LS) follow. It is surrounded by weak tundra gleys characterized by small frost cracks and cryoturbation. The lower part of the Holocene soil shows a lamination of silty and sandy layers, which indicates a fluctuation of the northern loess/sandy loess/sand boundaries during the Late Glacial (Fig. 35). Note that the OSL samples (GZW) were taken from another profile with the stratigraphic context displayed in Fig. 37.

6.3.4 Frankenbach The nature protection area Frankenbacher Gravel is located 1 km westwards of the city Heilbronn (Fig. 35). Up to 15 m of loess covers fluvial sands and gravels of the Necker River (Bibus et al., 2008). Pedostratigraphic investigations were conducted on several exposures by Bibus (2002) and Bibus et al. (2008) with additional grain-size analysis and micromorphological data. Palaeomagnetic data is available from a drill core extracted from the southeastern corner (Hambach et al., 2008). Detailed geochemical analysis were recently conducted by Krauß et al. (submitted to this volume).

The LPS Frankenbach (49.148839° N; 9.161553° E, 189 m asl) is situated in the northeastern corner of the nature protection area on a northern exposed slope of a dry valley along the eastern side of the Lein valley. The pedostratigraphic situation was previously presented by Bibus et al. (2008). The sequence consists of 6 m of the Last Glacial loess (Fig. 37). The base of the profile is build-up of two dark humic horizons (Mosbacher Humus Zone, MHZ) of the EG steppe soil phase. The upper unit shows loess filled crotovinas which are truncated by erosion (Fig. 38B and C). They are covered by colluvial sediments (Niedereschbach Zone), which are divided in a lower more humic unit and an upper part dominated by reworked Bt material (Fig. 38C). The typical appearance of fine lamination is not visible due to strong bioturbation. In a crotovinas of the lower part, a fine lamination of loess, reworked steppe soil and Bt layers is observed (Fig. 38C). The Niedereschbach Zone is followed by homogenous MPG loess with two interstadial soils. The lower soil has a light-brownish colour with secondary carbonate precipitation. The olive-green upper soil shows the typical features of the Lohne Soil (LoS, cf. 113

114 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

Bibus, 2002) with a fine platy structure and manganese precipitation. The top is also truncated and covered by strongly bleached loess with rusty thin bands (E0). Above, niveo-aeolian loess of the UPGa follows with an intercalated intensive tundra gley (E2). The upper 1.4 m were not accessible due to nature protection requirements.

Fig. 37: Simplified stratigraphies of the investigated LPS and position of luminescence samples. The stratigraphic units were structured according to the climatic stages of the Last Glacial cycle. Ringen and Romont West are composites of four consecutive profiles. The depth of OSL samples in the drawing differ from the sample depth below surface in table 1. OSL samples from Garzweiler were taken from another section which was exposed several years earlier and has already been removed due to mining activity. The sampling position bracketing the Leonard Soil is confirmed. The relative stratigraphic position of samples is plotted in the drawing of the section Garzweiler. Q = quartz, PM = polymineral. Units: NC: Nagelbeek Complex; KL: Kesselt Layer; EU: Eben Unconformity; HV: Harveng Soil; LV: Les Vaux Soil; KC a/b: Kincamp Soils; MP: Malplaquet Soil; HCR: Humiferous complex of Remicourt; WHM: Whitish Horizon of Momalle; VSG-A/B: Villers-St-Ghislain Soil; HaS: Harminigies Soil; ET: Eltville Tephra; LS: Leonard Soil; E0-4: Erbenheim Soils; G1-4: Gleys; BS1-5: Boreal Soils; NEZ: Niedereschbach Zone; MHZ: Mosbacher Humus Zone; LoS: Lohne Soil; BS: Böcking Soil; ES: Erbach Soil. STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 115

Fig. 38: Photos displaying the EG and LPG sediments from the investigated LPS. Photo A shows the EG and LPGa sequences from Romont West with the Humifereous complex of Remicourt at the base covered by laminated colluvium. The Maplaquet and Kincamp A/B Soils are disturbed, probably reasoned by thermocast erosion. Photo E shows the prolongation of laminated colluvium above the Kincamp A/B Soil with crotovinas (photo F) and the probable remnants of the Les Vaux Soil. Photo C shows the EG and LPG sediments from Frankenbach with frequent crotovinas (photo B). One of these show a fine lamination related to slope wash and subsequent deposition of the upper Niedereschbach Zone and give evidence for intense bioturbation after or during the deposition of the lower Niedereschbach Zone. Photo H displays the Eemian-EG-LPG transition in an exposure close by the investigated profile. The EG humic soils shows frequent crotovinas and root channels (photo D) with an incised former river bed (photo G). Photos: J. Zens.

115

116 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

6.4 Methods Detailed methodological descriptions of luminescence dating and grain-size analysis are given in the following sections. Information on fieldwork, sampling strategy and resolution as well as geochemical analysis (X-ray fluorescence and CaCO3 determination) are embedded in the supplementary material S6_1.

6.4.1 Luminescence dating 6.4.1.1 Sample preparation and measurement equipment

OSL samples were extracted under subdued red light and pretreated with HCl (10%), H2O2

(10%) and Na4P2O7 (0.01N) to remove carbonates, organic material, and to disperse soil aggregates. Grain-size separation was conducted by sieving (40-63 µm, GZW1-3) and settling using Stokes law (4-11 µm, remaining samples). Subsamples were etched with hexafluorosilicic acid (H2SiF6, 40 %) to extract pure quartz separates. The samples were sedimented on steel discs with a diameter of 9.8 mm (1-1.2 mg/disc). Continuous wave OSL (CW-OSL) was carried out on automated Risø TL/OSL DA 15/20 readers equipped with a 90Sr/90Y beta irradiation source (~0.089-0.154 Gy/sec). Quartz samples were stimulated with blue LEDs (470 ± 30 nm) for 40 s at 125°C (Murray and Wintle, 2000, 2003). The luminescence signal was detected passing a 7.5 mm Hoya-350 glass filter (330 ± 40 nm). Polymineralic fine grain samples were illuminated with infrared LEDs (880 ± 80 nm) held for 200 s at 290°C (Thiel et al., 2011). The emitting luminescence signal was measured passing an interference filter (410 nm).

6.4.1.2 Dosimetry The environmental dose rate was measured using a high-purity gamma-ray spectrometer with a germanium detector. The gravimetric in-situ water content was corrected with conversion factors presented by Zimmermann (1971). Dose rate conversion factors by Liritzis et al. (2013) and alpha and beta attenuation factors by Bell (1970) and Brennan (2003) were applied. According to Huntley and Baril (1997), a potassium content of 12.5 ± 0.5 % was assumed for the internal beta dose rate of polymineral fine grain samples. Alpha efficiency values of 0.036 ± 0.003 for quartz (Kreutzer et al., 2012a) and 0.086 ± 0.02 for feldspar (Rees- Jones, 1995) were assumed. The cosmic dose rate was calculated according to Prescott and Hutton (1988, 1994) and the total dose rate with the DRAC online tool Version 1.2 (Durcan et al., 2015).

STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 117

6.4.1.3 Luminescence measurement procedure Quartz OSL measurements were conducted using the SAR protocol (Murray and Wintle, 200, 2003). The early background subtraction was applied by subtracting the signal of 0.48-1.6 s from the initial 0.32 s of the shine down curve (Ballarini et al., 2007; Cunningham and Wallinga, 2010). Preheat-plateau tests were carried out for temperatures between 180 and 280 °C held for 10 s and a cut heat 20°C below the chosen preheat temperature. The occurrence of feldspar contamination was tested by determining the IR depletion ratio (Duller, 2003). Dose recovery tests were conducted using laboratory beta doses similar to the expected burial dose and bleaching for 100 s with blue LEDs at room temperature.

Polymineral samples were measured with the pIRIR290 SAR protocol (Thiel et al.,

2011a). The signal of the initial 4 s was used for equivalent dose (De) calculation after subtracting the signal of the final 20 s. First-IR stimulation temperature tests were conducted by varying the temperature of the first IR bleach between 50 and 220°C prior to the stimulation of the pIRIR290 signal (Buylaert et al., 2012). Dose recovery tests were conducted by applying laboratory beta irradiation doses similar to the expected burial dose. The samples were bleached for 24 h with a Hönle SOL2 solar stimulator. The residual doses were measured after applying the same bleaching procedure and were then subtracted from the De determined in dose recovery experiments. Fading tests were carried out for selected samples of each profile (RMT2_7, RMT1_15, RGE-4, RGE-16 and NSG-5) using three aliquots per sample and a laboratory dose close to the equivalent dose. Storage times varied between 30 min and 16 h and were normalized to a delay time of two days (Auclair et al., 2003). The g value as the percentage of signal loss per decade was calculated according to Huntley and Lamothe (2001).

De values were determined for 6-16 aliquots. Data analysis was conducted using the Risø Luminescence Analyst (version 4.31.9) and the R package Luminescence (version, 0.6.1)

(Kreutzer et al., 2012b). The De distribution was checked for outliers by the inter quantile range method (Tukey, 1977) and the final De was calculated using the average mean. The Central Age Model was chosen if overdispersion was observed (Galbraith et al., 1999). All uncertainties are given by the 1σ uncertainty.

6.4.2 Grain size analysis Grains-size distributions (GSD) were determined using a Laser Diffraction Particle Size Analyzer (LS13320, Beckman Coulter). The sample preparation followed the procedure presented in Schulte and Lehmkuhl (2017). The Lorenz-Mie theory was applied to calculate the percentage of grains associated with 117 grain-size classes (Fluid RI: 1.33; Sample RI: 1.55; Imaginary RI: 0.1) (ISO 13320, 2009; Özer et al., 2010; Schulte et al., 2016).

Two grain-size proxies were calculated to obtain palaeoenvironmental information. Schulte and Lehmkuhl (2017) introduced the ΔGSD proxy as an indicator for post-depositional 117

118 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

chemical weathering in LPS. It can be determined by subtracting the GSD calculated with the Lorenz-Mie theory from the GSD calculated with the Fraunhofer approximation. The refraction index is only be considered in the Lorenz-Mie theory and depends on the mineral properties. Hence, the difference between both GSDs (ΔGSD) is sensitive to the mineral composition of the sample and was introduced and interpreted as a suitable indicator of post- depositional chemical weathering in LPS, which is virtually unaffected by cryogenic processes (Schulte and Lehmkuhl, 2017).

The grain-size index (GSI) is defined as an index for wind dynamics and atmospheric dust (Rousseau et al., 2007; Antoine et al., 2009). It was calculated dividing the percentage of the fraction between 26 and 52.6 μm by the percentage of the fraction finer than 26 μm.

6.5 Results 6.5.1 Luminescence dating OSL measurements show comparable luminescence characteristics (preheat plateau, first- IR stimulation tests, dose recovery test; see Fig. 40, S6-2_Fig. 3) for both quartz and polymineral separates. Dose response curves are best fitted by a single saturating exponential fit except for samples NSG-1-Q, RMT1_13-Q and RMT3_10-PM where a single saturating exponential plus linear function results in the best fit (Fig. 39). Dose distributions of all samples are displayed in Figure 2 in the supplementary material S6-2.

Fig. 39: Typical quartz dose response and decay curves for the investigated samples.

Preheat plateau tests on quartz yielded constant De values for temperatures between 240 °C and 280 °C (Fig. 40A, C, G and E). Dose recovery experiments were conducted for preheat- temperatures of 260 °C or 280 °C and could successfully reproduce a laboratory dose similar STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 119

to the De within 10 % of unity (Tab. 7). Therefore, preheat temperatures of 260 °C and 280 °C were chosen for the equivalent dose determination. Feldspar contamination could not be observed as all IR depletion ratios vary around 10% of unity.

First-IR stimulation temperature tests on polymineral fine grain samples exhibit constant

De values for a temperature range from 50 °C to 180 °C (Fig. 40B, D, F and H). At 220 °C, most aliquots failed the recycling ratio criteria and had to be rejected. A first-IR stimulation temperature of 50 °C was chosen for further measurements. The residual doses after artificial bleaching for 24 hours in the solar stimulator vary between 2.21 ± 0.40 Gy (NSG-5) and 8.65 ± 0.44 Gy (NSG-1) and are comparable to residual doses reported from other LPS of Central Europe (e.g. Schmidt et al., 2011). Dose recovery ratios vary between 0.9 and 1.1, which indicate a successful recovery of laboratory doses (Tab. 7). Fading tests yield g-values below

1 % showing that the pIRIR290 signal is not affected by anomalous fading.

The total dose rates are summarized in Table 6. Radioactive disequilibria could not be observed in the decay chains of U, Th and K. The gravimetric in-situ water contents vary from ~10 % to ~25 %. Total dose rates of fine grain samples vary between 2.86 and 3.35 Gy/kyr for quartz and 3.39 and 4.03 Gy/kyr for polymineral separates, which are similar to values from other LPS (e.g. Frechen and Schirmer, 2011; Schmidt et al., 2011; Klasen et al., 2015). Maximum

De values of 1008 ± 51 Gy (RMT3_10) for polymineral and 254 ± 15 Gy (NSG-1) for quartz separates and ages of 293 ± 22 ka and 75.7 ± 6.7 ka are obtained, respectively.

Fig. 40: Results of preheat-plateau and first-IR stimulation temperatures tests for fine-grain quartz and polymineral separates. For every temperature, three to five aliquots were measured. The cutheat temperature was 20°C below the preheat temperature.

119

120 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

Tab. 6: Summary of dosimetry data. WC: water content; DRtot = total dose rate; Q = quartz, PM = polymineral; reworked means reworked palaeosols and loess layers. Detailed information will be included in the DRAC table (S2) of the online version of this article.

Radionuclide concentration

Lab. Sample Sediment Depth U Th K WC DRtot Q DRtot PM code code [m] [ppm] [ppm] [%] [%] [Gy/ka] [Gy/ka] C-L4152 RMT2_2 loess 3.18 2.73 ± 0.12 9.35 ± 0.47 1.43 ± 0.03 12.9 3.06 ± 0.19 0 C-L4154 RMT2_4 tundra gley 3.85 2.63 ± 0.12 9.62 ± 0.47 1.55 ± 0.03 17.5 3.02 ± 0.18 3.55 ± 0.19 C-L4155 RMT2_5 reworked 4.34 2.72 ± 0.12 9.98 ± 0.49 1.41 ± 0.03 9.8 3.18 ± 0.21 - C-L4156 RMT2_6 loess 4.71 2.85 ± 0.13 9.87 ± 0.48 1.38 ± 0.03 9.7 3.19 ± 0.21 3.81 ± 0.22 C-L4157 RMT2_7 loess 4.86 2.88 ± 0.13 10.10 ± 0.49 1.35 ± 0.03 9.9 3.19 ± 0.21 3.82 ± 0.23 C-L4159 RMT3_9 loess 5.65 2.83 ± 0.13 9.82 ± 0.48 1.37 ± 0.03 12.8 3.05 ± 0.20 - C-L4160 RMT3_10 soil 6.28 2.28 ± 0.11 10.25 ± 0.50 1.54 ± 0.03 17.4 - 3.44 ± 0.19 C-L4175 RMT1_15 reworked 4.90 2.89 ± 0.13 10.52 ± 0.48 1.56 ± 0.03 11.9 3.34 ± 0.20 3.96 ± 0.23 C-L4174 RMT1_14 reworked 5.10 2.82 ± 0.12 10.62 ± 0.52 1.56 ± 0.03 16.6 3.17 ± 0.20 3.76 ± 0.21 C-L4165 RMT1_5 reworked 6.30 2.60 ± 0.12 11.10 ± 0.54 1.60 ± 0.03 15 3.22 ± 0.21 3.81 ± 0.21 C-L4163 RMT1_3 Cambisol 6.95 2.39 ± 0.11 10.46 ± 0.51 1.81 ± 0.03 13.8 3.33 ± 0.20 3.88 ± 0.21 C-L4173 RMT1_13 steppe soil 9.40 2.91 ± 0.13 10.71 ± 0.52 1.47 ± 0.03 17.4 3.10 ± 0.20 3.69 ± 0.21 C-L2590 GZW-1 loess 17.0 2.60 ± 0.12 8.24 ± 0.45 1.43 ± 0.04 17.9 2.51 ± 0.12 - C-L2591 GZW-2 tundra gley 12.0 2.40 ± 0.11 8.04 ± 0.45 1.62 ± 0.05 16.2 2.81 ± 0.13 - C-L2592 GZW-3 loess 13.0 2.41 ± 0.11 8.14 ± 0.45 1.40 ± 0.04 15.8 2.58 ± 0.12 - C-L3924 RGE-4 tephra 2.03 3.23 ± 0.13 10.39 ± 0.50 1.43 ± 0.02 15.7 3.23 ± 0.21 3.86 ± 0.22 C-L4150 RGE-16 loess 2.38 2.97 ± 0.13 10.21 ± 0.50 1.38 ± 0.02 10.3 3.27 ± 0.22 3.90 ± 0.23 C-L4149 RGE-15 loess 2.93 2.82 ± 0.12 10.10 ± 0.49 1.42 ± 0.03 11.7 3.19 ± 0.21 3.80 ± 0.22 C-L4148 RGE-14 loess 3.40 2.61 ± 0.11 9.88 ± 0.48 1.41 ± 0.03 18.8 2.88 ± 0.18 3.41 ± 0.19 C-L4147 RGE-13 loess 4.61 2.93 ± 0.13 10.30 ± 0.48 1.46 ± 0.03 24.6 2.86 ± 0.18 3.39 ± 0.19 C-L4146 RGE-12 cambisol 5.68 2.58 ± 0.11 10.73 ± 0.52 1.53 ± 0.03 20.6 2.97 ± 0.18 3.44 ± 0.19 C-L4145 RGE-11 loess 7.02 2.52 ± 0.12 9.97 ± 0.49 1.52 ± 0.03 18.5 2.94 ± 0.18 3.46 ± 0.19 C-L4028 NSG-5 tundra gley 2.78 3.04 ± 0.13 10.29 ± 0.51 1.21 ± 0.02 11.3 3.10 ± 0.21 3.74 ± 0.22 C-L4027 NSG-4 loess 3.30 3.23 ± 0.14 11.34 ± 0.56 1.30 ± 0.02 14.3 3.22 ± 0.22 3.89 ± 0.23 C-L4026 NSG-3 loess 3.85 3.13 ± 0.14 11.29 ± 0.55 1.38 ± 0.03 15.0 3.23 ± 0.21 3.88 ± 0.23 C-L4025 NSG-2 reworked 4.94 3.32 ± 0.14 12.98 ± 0.64 1.52 ± 0.03 21.5 - 3.98 ± 0.23 C-L4024 NSG-1 steppe soil 5.23 3.61 ± 0.15 12.82 ± 0.62 1.49 ± 0.02 21.7 3.35 ± 0.22 4.03 ± 0.23

STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 121

Tab. 7: Summary of dating results from the investigated samples. DRT: Dose recovery Test. Detailed information will be included in the DRAC table (S2) of the online version of this article.

Lab. Sample Depth De PM De Q DRT PM DRT Q Age Q Age PM code code [m] [Gy] [Gy] ratio ratio [ka] [ka] C-L4152 RMT2_2 3.18 - 66.2 ± 3.4 - 0.96 ± 0.02 21.7 ± 1.8 - C-L4154 RMT2_4 3.85 91.6 ± 4.6 70.0 ± 3.6 0.94 ± 0.01 - 23.2 ± 1.8 25.8 ± 1.9 C-L4155 RMT2_5 4.34 - 79.5 ± 4.0 - - 25.0 ± 2.1 - C-L4156 RMT2_6 4.71 100.6 ± 5.2 80.8 ± 4.1 1.01 ± 0.01 0.99 ± 0.04 25.3 ± 2.1 26.4 ± 2.1 C-L4157 RMT2_7 4.86 98.0 ± 5.0 78.2 ± 4.0 1.02 ± 0.01 1.00 ± 0.05 24.5 ± 2.0 25.7 ± 2.0 C-L4159 RMT3_9 5.65 - 76.3 ± 3.9 - 0.98 ± 0.02 25.0 ± 2.1 - C-L4160 RMT3_10 6.28 1008 ± 51 - - - - 293 ± 22 C-L4175 RMT1_15 4.90 169.6 ± 8.6 143.9 ± 7.3 - - 43.1 ± 3.5 42.8 ± 3.3 C-L4174 RMT1_14 5.10 374.7 ± 18.9 202.6 ± 10.2 - 0.95 ± 0.01 63.8 ± 5.1 99.8 ± 7.5 C-L4165 RMT1_5 6.30 272.0 ± 13.9 201.8 ± 10.2 0.95 ± 0.02 - 62.6 ± 5.0 71.4 ± 5.4 C-L4163 RMT1_3 6.95 340.0 ± 17.1 221.2 ± 11.3 0.96 ± 0.03 - 66.5 ± 5.2 87.6 ± 6.4 C-L4173 RMT1_13 9.40 264.4 ± 13.3 193.5 ± 9.7 - - 62.4 ± 5.1 71.7 ± 5.4 C-L2590 GZW-1 3.70 - 45.0 ± 2.7 - - 17.9 ± 1.4 - C-L2591 GZW-2 4.40 - 45.5 ± 2.5 - - 16.2 ± 1.2 - C-L2592 GZW-3 5.20 - 40.7 ± 2.3 - - 15.8 ± 1.6 - C-L3924 RGE-4 2.03 92.5 ± 4.6 77.8 ± 4.0 - 0.93 ± 0.04 24.1 ± 2.0 24.0 ± 1.8 C-L4150 RGE-16 2.38 103.1 ± 5.2 86.9 ± 4.4 0.97 ± 0.02 1.00 ± 0.03 26.6 ± 2.2 26.4 ± 2.0 C-L4149 RGE-15 2.93 103.8 ± 5.3 81.2 ± 4.2 - - 25.4 ± 2.1 27.3 ± 2.1 C-L4148 RGE-14 3.40 94.8 ± 4.8 74.3 ± 3.9 - - 25.8± 2.1 27.8 ± 2.1 C-L4147 RGE-13 4.61 99.6 ± 5.1 83.7 ± 4.4 - - 29.3 ± 2.4 29.3 ± 2.2 C-L4146 RGE-12 5.68 161.2 ± 8.2 127.9 ± 6.6 - - 43.1 ± 3.4 46.9 ± 3.5 C-L4145 RGE-11 7.02 212.0 ± 11.0 179.9 ± 9.1 1.01 ± 0.00 0.93 ± 0.02 61.2 ± 4.8 61.3 ± 4.6 C-L4028 NSG-5 2.78 111.0 ± 5.6 98.9 ± 5.2 - - 31.9 ± 2.7 29.7 ± 2.3 C-L4027 NSG-4 3.30 212.3 ± 10.8 171.8 ± 9.3 1.06 ± 0.01 - 53.3 ± 4.6 54.6 ± 4.3 C-L4026 NSG-3 3.85 272.5 ± 14.0 194.7 ± 9.9 1.03 ± 0.02 0.95 ± 0.01 60.3 ± 5.0 70.8 ± 5.5 C-L4025 NSG-2 4.94 269.8 ± 13.6 - - - - 67.8 ± 5.2 C-L4024 NSG-1 5.23 313.2 ± 15.8 253.7 ± 14.8 0.94 ± 0.02 - 75.7 ± 6.7 77.6 ± 6.0

6.5.2 Sedimentology and geochemistry

Fig. 41 illustrates the results of grain-size analysis and CaCO3 determination. The ΔGSD signal traces the division into substages and the occurrence of sedimentary breaks by remarkable changes in the submicron and cSi/fS ranges (e.g. EG at Romont West, UPGa/b boundary at Romont East, Fig. 41 and 42). Similar patterns of the ΔGSD signal can be observed for the same stages of all sections which is supporting the division into substages.

As a whole, the ΔGSD signals for the submicron grain-size range are weak with values centred around zero in the carbonate containing loess samples. Interstadial palaeosols are indicated by negative values. The UPG have a consistently weak ΔGSD in the submicron range (̶̶̶̶–0.09 to 0.03). The MPG soils show a characteristic signal, which occur in a comparable magnitude for the different sections (up to –0.21). More prominent values (up to –0.35) are reached in the Harminigies Soil (Romont West) or in the rather reworked soil sediments of the LPG (Romont West, Ringen, Frankenbach). In contrast, humic steppe soils of the EG (Romont West, Frankenbach) show comparatively weak ΔGSD signals.

For most of the sequences the contents of the submicron grain-size fraction have higher variability than the ΔGSD within the same range. The prominent ΔGSD signatures for the interglacial and interstadial palaeosols are followed by excursions of the submicron fraction (up to 15 vol%). But the increased values of the submicron fraction for some of the humic 121

122 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

horizons (e.g. up to 8.5 vol% for the NC in Romont West and East) are not reflected by the ΔGSD signal. Interestingly, in case of the Garzweiler sequence the variation of the ΔGSD signal is virtually unaffected by the increase of submicron particles.

The GSI is depicted for all sequences. Especially the sediments which correlate with the UPGa reach continuously high values (up to 1.52) except of Romont West where the UPGa is reduced. The values for the other units vary mainly within a lower range (from 0.47 to 1.06). Remarkably, for Romont East, Ringen and Garzweiler the high values of the GSI are accompanied by a considerable signature of the ΔGSD occurring around the boundary between cSi and fS (Fig. 41). The combination of both signals indicates two distinct phases of aeolian dynamics during the UPGa.

The fine sand fraction (fS, 63 – 200 µm) shows a relatively high variability with depth for all sequences. The contents vary between 6 and 17.8 vol% in Garzweiler, 7.2 and 29.5 vol% in Romont East, 5.7 and 41.6 vol% in Romont West (not shown) and 1.5 and 21.7 vol% in Ringen. The highest values correspond with the hill washed deposits of the LPG (Romont West, Ringen, Frankenbach).

The CaCO3 curve progression at all sites is in most cases similar to the ΔGSD pattern, especially within the UPG sediments. Within these sediments the carbonate content varies between 10 and 20 vol% for Romont West/East and Garzweiler, for Ringen between 5 and 10 vol%, but reaches high values (up to 34 vol%) for Frankenbach. STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 123

Fig. 41: Summary of results from OSL dating, grain size analysis and CaCO3 determination. The ΔGSD signal is visualized by heatmaps and traces the sub division into climatic stages. Every data point of the heatmap visualize the difference between the vol % of grains determined with the Fraunhofer approximation and the Lorenz-Mie theory for each of the 117 grain size classes recorded by laser diffraction.

123

124 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

Fig. 42: Example for the change in the ΔGSD signal at sedimentary breaks for the Eemian, EG and LPG transitions at Romont West. The low values of the ΔGSD signal of the HCR are clearly separated from the underlying EG VSG-A/B. WHM abbreviates Whitish horizon of Momalle (cf. Haesaerts and Mestdagh, 2000).

6.6 Discussion 6.6.1 Luminescence dating OSL ages support the litho-pedostratigraphic interpretation that the LPS mainly cover the Last Glacial cycle with the exception of the lower units of Romont East which are placed to the middle Saalian or even older by a pIRIR290 age of 293 ± 22 ka (RMT3_10). The good accordance between blue OSL and pIRIR290 ages from Romont East, Ringen and Frankenbach confirm the suitability of the measurement setup and serves as a valuable internal control of the dating methods. The age estimates support the lithostratigraphic classification into substages.

However, inconsistent ages have been observed for LPG and EG sediments from Romont West and Frankenbach (see Fig. 37 and Tab. 7, RMT1_14, RMT1_5, RMT1_3, RMT1_13 and NSG-3). The expected age ranges for these phases are assumed to be ~60-78 ka (see Fig. 36, Haesaerts et al., 2016; Schirmer, 2016) or ~59-70 ka (see Fig. 36, Antoine et al., 2016) for the

LPG, and back to ~110 ka for the EG. Whereas quartz ages fit to the expectation, pIRIR290 ages seems to overestimate the burial age.

6.6.1.1 Reliability of quartz ages

The discrepancy between quartz and pIRIR290 ages for the EG and LPG sediments from Romont West may be reasoned by the lower saturation level of quartz. Quartz is known to saturate at much lower doses than feldspar minerals (e.g. Roberts, 2008). The upper limit of equivalent doses of fine-grained loess deposits with dose rates between 3-4 Gy/kyr was recently investigated for Romanian loess (Timar-Gabor and Wintle, 2013; Timar-Gabor et al., 2015). The comparison of natural and laboratory generated dose response curves (DRC) STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 125

revealed diverging shapes starting at De values around 200 Gy (Timar-Gabor et al., 2015). At high doses, laboratory DRCs show an additional growing component (linear or double saturating exponential), whereas natural DRCs were best approximated by an exponential fit and hence saturate at much lower doses. At the dose level where both curves start to diverge, age underestimation was observed. Therefore, De values determined from laboratory DRC different from a single saturating exponential was suggested to be treated with caution (Chapot et al., 2012).

Equivalent doses of samples from the LPG and EG vary between 180 ± 9 Gy (RGE-11) and 254 ± 15 Gy (NSG-1) (Tab. 7) and are best fitted by a single saturating exponential function despite of RMT1_13 where an exponential plus linear fit results in the best approximation (Fig. 39). Age estimates (besides RMT1_13) are in agreement with fine grain quartz chronologies from Havrincourt (Antoine et al., 2014), Tönchesberg (Schmidt et al., 2011), Seilitz (Meszner et al., 2013), Ostrau (Kreutzer et al., 2012a) and Dolni Vĕstonice (Fuchs et al., 2013) (Fig. 45). Although, most DRCs of these studies were best fitted by an exponential plus linear function, age estimates also fit to the stratigraphic expectations for ages up to 80 ka and De values up to ~200-250 Gy. At Tönchesberg and Seilitz, the crosscheck with fading corrected IRSL and pIRIR225 ages additionally confirm the reliability of quartz ages in this dose range. For Dolni Vĕstonice even much higher De values and ages were evaluated as being robust (Fuchs et al., 2013) and consequently quartz from Western and Central European loess seems to be suitable at least up to ~250 Gy.

The quartz OSL age of 62.4 ± 5.1 ka of sample RMT1_13 is clearly lower than a pIRIR290 age of 71.7 ± 5.4 and do not fit to the expected minimum age of the humic steppe soil of > 70 ka according to Antoine et al. (2016). This may be reasoned by different luminescence properties, e.g. a lower saturation limit, which can be interpreted as change in the source material. RMT1_13 has the brightest luminescence signal of all samples investigated here and the lowest De compared to the subsequent samples RMT1_14, RMT1_5 and RMT1_3 (Tab. 7, S6-2_Fig. 3). A clear change in the brightness of the luminescence signal was interpreted by Schmidt et al. (2011) as an indicator for a change in the source material. Further evidence is given by elemental analysis. Fig. 43 displays the aluminium (Al) and silicium (Si) contents for Romont West. The Al/Si ratio is an indicator of pedogenetic clay formation, because Al accumulates in clay minerals as a result of hydrolyse relative to the parent silicate mineral such as quartz (Sheldon and Tabor, 2009). The ratio is centred around 0.2 for the Weichselian deposits and show small peaks in the Les Vaux Soil, EG forested soils and the Eemian Soil which are accompanied by a shift to finer grain sizes (Fig. 41, S6-2_Fig. 1). The strong decrease of Al in the Humifereous Complex of Remicourt from top down corresponds to an increase of particles < 6.3 µm bottom-up. In combination with the maximum values of Si (evidence for increasing aeolian activity/quartz input), further evidence for a provenance change of loess for this period is given. Haesaerts et al. (2016) suggested that the Humifereous Complex of Remicourt was developed in homogeneous loess deflated from local sources. However, the 125

126 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

decreasing grain-size trend at Romont West points to distal sources as suggest for the so- called marker silts at Dolni Vĕstonice (Kukla and Koci, 1972; Antoine et al., 2013) and the Tönchesberg (Schmidt et al., 2011). They were supposed to originate from large scale dust storms and may have been provided the source material for the Humifereous Complex of Remicourt. Heavy mineral analysis could finally solve this open question for sample RMT1_13.

Since no indication of signal saturation for the quartz samples under study is given and the estimates ages are in agreement with other studies and stratigraphic evidence, we assume that the quartz chronologies are reliable and attribute the discrepancy to insufficient bleaching of the pIRIR290 signal (see Section 6.6.1.2).

Fig. 43: Elemental contents and Al/Si ratio for the LPS Romont West. The ratio is an indicator for pedogenetic clay formation as a result of relative enrichment of Al by hydrolyse (Sheldon and Tabor, 2009). STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 127

6.6.1.2 Reliability of pIRIR290 ages Age inconsistencies exist between different luminescence dating methods applied to polymineral fine grains of LPG sediments from the Belgian loess sections Kesselt, Momalle (Van den Haute et al., 1998, 2003) and Harmignies (Frechen et al., 2001) and fine-grained quartz at Havrincourt (France, cf. Figs. 35 and 41) (Antoine et al., 2014). In particular the unique character of the frequently reworked LPG sediments makes the accurate dating challenging (Frechen et al., 2001; Meszner et al., 2013; Antoine et al., 2016; Haesaerts et al., 2016).

Colluvial deposits are known to be prone to partial bleaching due to short transport distances along hillslopes and reduced light exposure as a function of magnitude and frequency of the erosive process (Fuchs and Lang, 2009). However, luminescence signals are known to bleach at different rates (Godfrey-Smith et al., 1988), and can, when combined, provide evidence for partial bleaching (Fuchs et al., 2005; Kadereit et al., 2006; Vandenberghe et al., 2007; Murray et al., 2012). Quartz bleach much faster than feldspar signals (Thomsen et al., 2008; Murray et al., 2012; Buylaert et al., 2012). Murray et al. (2012) observed that after 10 s of bleaching, the quartz signal was reduced to ~5 %, the IRSL signal to ~60 % whereas the pIRIR290 signal showed a residual of ~98 %. Comparable rates were also observed by Colarossi et al. (2015).

The degree of signal resetting in colluvial deposits depends on the character of the transport process (Fuchs and Lang, 2009). High magnitude events hamper signal resetting especially for slowly bleachable signals due to rapid relocation along the slope and subsequent burial. Low magnitude and high frequency processes extend the time of light exposure until the final burial and hence the probability of fully signal resetting is given. The fine sand content of the LPG sediments can be used as an indicator for the transport capacity of the erosive process. For samples RMT1_14 and RMT1_3, local maxima of fS and mS (S6-2_Fig. 1) are indicative for high magnitude low frequency processes where the duration of light exposure was probably not sufficient for complete resetting of the pIRIR290 signal. Even if the quartz ages correspond to the expected ages, residual signals for previous dose-bleaching cycles cannot be fully excluded. In case of RMT1_5, the lower fS values rather indicate a high frequency low magnitude process with an increased storage period on the slope resulting in coinciding ages within error margins (Fig. 41, S6-2_Fig. 1). Hence partial bleaching of the pIRIR290 signal is likely the explanation for the age overestimation. According to grain-size data from the sediments where the remaining pIRIR290 ages were generated from, sufficient bleaching can be assumed strengthened by the good accordance with quartz ages.

In addition, individual grains can be coated by iron oxides, carbonate or organic matter and bound together to aggregates with unbleached grains encased (Bush and Feathers, 2003). If coatings are not removed and aggregates are not fully broken down during fluvial reworking, this can lead to a mixture of well-bleached grains from the outer edge of 127

128 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

aggregates and unbleached grains from the inside of aggregates. Due to the larger surface area of fine-grained feldspars compared to quartz, the probability of aggregation by physical, chemical and biological bonds is elevated. However, the amount, composition and stability of aggregates influencing the fine grain fraction can vary according to the source material and type of soil formation (e.g. Slattery and Burt, 1997; Beuselinck et al., 2000) and hence is difficult to estimate for the heterogeneous LPG sediments.

Portable OSL measurements can serve as a tool to investigate this issue (see S6_2). Due to the measurement of a bulk sample without destroying the sedimentary structure and removing chalk and organic material, additional information can be provided if the quartz and feldspar signals are normalised to a reference value and compared with each other. Fig. 44 displays the pOSL curves where the signal is normalised to the uppermost sample. It originating form homogeneous loess with precise age control. The normalisation enables a better comparability of quartz and polymineral signals and can give information concerning relative changes in the mineral composition and partial bleaching. The bulk pOSL signal originates predominantly from single grains and grains from the outer edge of aggregates with the highest probability of bleaching during transportation. Similar OSL and IR signals for the sediments between samples RMT1_14 and RMT1_5 are unexpected since the overestimation of pIRIR290 ages is attributed to partial bleaching. This might suggest that for this part of the sequence a larger proportion of feldspar grains was encased in aggregates contributing to the overestimation of the pIRIR290 age. Below sample RMT1_5, the pIRIR290 signal is between 24 and 110 % more intense, than the quartz signal indicating a higher contribution of partially bleached grains (Fig. 44).

Consequently, the averaged OSL signal of any fine grained fraction mask the heterogeneity of individual De values resulting from the properties of the source material and the transport processes and can lead - if the percentage of partially bleached grains increases - to age overestimation (e.g. Bateman et al., 2003; Bush and Feathers, 2003; Duller, 2008). In case of the

LPG sediments, partial bleaching of the pIRIR290 signal is interpreted as the major reason for the age overestimation. STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 129

Fig. 44: Portable OSL signals from Romont West and East. Samples were taken every 20 cm and around sedimentary breaks. The pOSL signals are normalized to the uppermost sample originating from homogenous well- bleached loess of the UPGb. Methodology is described in S6- 1.

6.6.2 Chronostratigraphy and palaeoenvironmental implications The studied profiles presented in this study highlight the difficulties associated with loess deposits that have undergone phases of erosion in a periglacial environment. Even where high-resolution records exist (e.g. LPG in Romont West) some units are missing in contrast to the idealized stratigraphic stacks (see Fig. 36). However, here we combine comparative OSL age with grain size to establish reliable chronologies for the profiles under study. Interestingly, when comparing our results with the existing stratigraphic schemes, discrepancies to the Belgium and Lower Rhine Embayment systems become obvious which deserve further discussions (Figs. 36 and 37).

129

130 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

The new results are integrated into a transect of well-dated (e.g. SAR protocol, pIRIR and/or fading correction) LPS from Northern France towards the Czech Republic (Fig. 45). Our study demonstrates that even if no profile yield the entire sequence of the Last Glacial cycle, it is possible to correlate major units, especially palaeosols, by means of reliable age information and stratigraphic evidence. The composite profile displayed in Figure 46 is the result of combining sub sequences of each profile under study by numerical age control and stratigraphic evidence. By integrating the ELSA Stacks and Greenland ice core data, a more reliable event-stratigraphy can be developed enhancing existing stratigraphic models (cf. Fig. 36). STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 131

Fig. 45: Transect of selected LPS from Northern France towards the Czech Republic and their correlation by palaeosols, periglacial features and OSL dating. Havrincourt provides a high-resolution fine-grained quartz chronology for the LPG and MPG and serves as key section for these periods in Northern France (Antoine et al., 2014). The LPS Schwalbenberg II provides the most detailed record of the MPG and is located 9.5 km eastwards of Ringen

(Schirmer, 2012). OSL dating was applied using pIRIR225 and fading corrected IRSL signals of polymineral fine grains (Frechen and Schirmer, 2011). OSL ages of the Tönchesberg section were determined using fine-grained quartz and polymineral samples and a fading correction was applied (Schmidt et al., 2011). The chronology of LPS Dolni Vĕstonice is based on fine-grained quartz ages (Fuchs et al., 2013). TG: tundra gley; BBS: brown boreal soil complex; IHS: isohumic soil; LBS: Lehmbröckelsande. Further abbreviation of units can be found in Fig. 36 and 37.

131

132 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

Fig. 46: Composite profile for the investigated section and correlation of palaeosols to NGRIP (Rasmussen et al., 2014; Seierstad et al., 2014) and the landscape evolutions zone (LEZ) of the ELSA Vegetation stack (Sirocko et al., 2016). The ELSA Flood Stack of the Auel maar provides information about the amount of flood events as indicator for extreme weather events (Brunck et al., 2016). The ELSA Tephra Stack composed tephras found in the Eifel maars (Förster and Sirocko, 2016).

6.6.2.1 Eem and Early Glacial No numerical age information was generated from Eemian and EG forested soil phase sediments. The distinct ΔGSD signal attributed to these units at Romont West and Frankenbach (Fig. 41) is comparable to interglacial soils from the profile Semlac (Romania) ranging between -0.3 and -0.5 (Schulte and Lehmkuhl, 2017) and can be used as reference STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 133 values for high content of secondary clay minerals as a function of post-depositional silicate weathering.

Age estimates between 71.7 ± 5.4 ka and 77.6 ± 6.0 ka from the dark humic horizons of the steppe soil phase (Romont West and Frankenbach) correspond with quartz OSL ages from the uppermost isohumic (Chernozem) soil (IHS3b) of the EG reference section Dolni Vĕstonice (Fig. 45, Fuchs et al., 2013). The ages indicate a deposition of the parent material between the cold stages of GS-21 and/or GS-20 or an ongoing loess sedimentation contemporaneous the pedogenesis during the first strong aeolian input towards Greenland during the GI-20 and GI- 19 (Fig. 46, Rasmussen et al., 2014). The latter hypothesis is strengthened by the decreasing GSI from bottom to top in the Humifereous Complex of Remicourt (Fig. 41, S6-2_Fig. 1) and the change in the chemical composition (Fig. 43), both indicating a transport from distal sources. The correlation of the palaeosol is in agreement with the chronostratigraphy of Northern France (Fig. 36, Antoine et al., 2016).

6.6.2.2 Lower Pleniglacial The onset of the LPG is characterized by a discontinuity as a result of extensive hillslope erosion (see Fig. 38C and G) caused by bare or unvegetated surfaces during a climatic deterioration (Haesaerts and Mestdagh, 2000). The sedimentary sequence shows a bisection into two phases. The first phase (LPGa) is dominated by reworked sediments, which were redeposited as a finely laminated colluvium (Fig. 38A, B, C, E and G). The corresponding submicron ΔGSD signal confirms the field interpretation of a dominance of either reworked Bt/Bth (low values) or humic soil material (close to zero) (Fig. 41). Aeolian dynamics are weak during this time indicated by low GSI values (Fig. 41). The base of the colluvial deposits was dated to 67.8 ± 5.2 ka at Frankenbach, which is in accordance with dating results from Havrincourt, Tönchesberg and Dolni Vĕstonice within the same stratigraphic context (Fig. 45). Considering the OSL ages from the uppermost EG humic soil, the onset of the LPG happened after the GI-19.1 or 19.2 (Fig. 46, Rasmussen et al., 2014), which is in conflict with the schemes from Belgium and the Lower Rhine Embayment (see Fig. 36).

The second phase (LPGb) is characterized by the increasing aeolian activity and the deposition of calcareous loess (Fig. 41). Shortly after a first depositional period, interstadial soil formations (Malplaquet, Knicamp A/B, BS1) document a climatic warming (Fig. 45). The ΔGSD signal indicates that the BS1 underwent more intense pedogenesis than the palaeosols from Romont West (Fig. 41). However, it may also be contaminated by reworked Bt material. The disintegration of the laminated colluvium at Frankenbach and two generations of crotovinas within the Niedereschbach Zone (see Figs. 38B-C and 47) may be interpreted as an evidence for interstadial conditions contemporaneous to the palaeosols from Romont and Ringen. The occurrence of a gravel layer within the superimposed calcareous loess at Ringen also indicates erosion events by slope wash. At Romont West, the colluvium continued above 133

134 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

the Kincamp A/B. Nevertheless, hill-washed deposits were observed for the initial phase of the MPG at several LPS from the area, and hence a correlation to this substages seems also possible.

Fig. 47: Photos of potential thermokast erosion features from Romont West. The first event (A) is incised into the Kincamp A/B and Malplaquet Soils. The upper boundary remains uncertain. The second event disturbed the Les Vaux Soil (B).

Quartz OSL ages from palaeosols at Romont of 62.4 ± 5.1 and 66.5 ± 5.2 ka are in agreement with age estimates of 65.0 ± 3.8 and 67.6 ± 3.9 ka from the Havrincourt Brown Silts of the Havrincourt site (Fig. 45). However, Antoine et al. (2014, 2016) questioned if the Havrincourt Brown Silts reflects a climatic warming, because their pedogenetic proxies do not show a pattern comparable to a typical interstadial soil. The weak submicron ΔGSD signal of the Malplaquet Soil also indicates only weak chemical weathering (Fig. 41). Nevertheless, the humic Kincamp A/B Soil from Romont West clearly shows a climate improvement associated with a dense herb cover (Haesaerts et al., 2016). Consequently, the (multiple) pedogenesis is likely connected to the GI-18 (Rasmussen et al., 2014) according to OSL ages (Fig. 46).

6.6.2.3 Middle Pleniglacial The MPG contains the most challenging sedimentary sequence of the Last Glacial cycle. The reduced aeolian activity and frequent erosional events led to thin MPG sequences, which often consist only of one or two palaeosols (see Fig. 45). In addition, repeated pedogenetic overprinting of sediments challenges the differentiation of distinct palaeosols. Combining numerical ages with stratigraphic information (ice wedge casts, crotovinas) and proxy data is mandatory to develop a reliable stratigraphic model of the environmental evolution (cf. Antoine et al., 2016).

The onset of the MPG is represented by rapid climate warming which becomes evident by a sharp increase of the δ18O at the beginning of the GI-17 in the NGRIP core (cf. Fig. 46, Rasmussen et al., 2014). Antoine et al. (2016) connected a thermokarst erosion event (TK-2) to STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 135 this warming as a result of the rapid degradation of permafrost. Evidence for such a phenomenon was observed at Romont West between the Les Vaux and Kincamp A/B Soils (Fig. 47B). It shows a comparable habitus like thermokarst features from other LPS (e.g. Antoine et al., 2001). However, it was not possible to trace the surface of this event precisely and hence a temporal correlation with the TK-2 event deserves further investigations.

The first sedimentary unit of the MPG is light-brownish loess with secondary carbonate precipitation and crotovinas (Ringen and Frankenbach). This points to increasing temperatures and a denser vegetation cover. The submicron ΔGSD gives no or only weak indication for chemical weathering (Fig. 41). Comparable stratigraphic sequence was observed at Havrincourt and dated to 61.7 ± 4.0 ka, which agree with our results from Ringen and Frankenbach (Fig. 45). The OSL ages implies a deposition of the parent material during the late LPG and a subsequent weak pedogenesis during GI-17 and 16 (Fig. 46). Pollen records from the Eifel maars suggests a spruce forest for this phase (Fig. 46, LEZ 9, Sirocko et al., 2016).

The compiled OSL ages allows us to identify two major pedogenetic phases, which are separated by a phase of climatic fluctuations. All palaeosols are characterized by distinct and similar ΔGSD patterns and an increasing submicron grain-size content. This points to a comparable degree of silicate weathering and pedogenetic clay formation (Fig. 41).The first phase is represented by the Lower Brown Soil, Les Vaux Soil, Boreal Soil 2, Remagen-1 Soil, Böcking Soil and Boreal Brown Soil (Fig. 45). The deposition of the parent material was dated to 57-51 ka. This may be indicative for an ongoing loess sedimentation or reworking of sediments contemporaneous to the pedogenesis during the warm GI-14 and 13 (Fig. 46). However, the ELSA Vegetation Stack reconstructed a spruce-hornbeam forest (LEZ 8) between 55-49 ka which rather indicates landscape stability (Fig. 46, Sirocko et al., 2016).

After the GI-13, a phase of fluctuating climatic conditions is followed by an initial period of erosion. The truncation of the BS2 and the Les Vaux Soil corresponds to frequent flood events recorded in the ELSA Flood Stack between 45-44 ka (Fig. 46, Brunck et al., 2016). They are interpreted as an indicator for a vegetation decrease due to a climatic deterioration (Sirocko et al., 2016). Ice wedge casts penetrating the soils formed under permafrost conditions. Stratigraphically, the ice wedges correspond with the F5 level (44-43 ka) from Northern France and an unspecified level in the Belgian system (Fig. 36, Antoine et al., 2016; Haesaerts et al., 2016). The overlying sediments were dated between to 47-42 ka (Fig. 45). At Ringen the Boreal Soil 2 is developed in these sediments, likely connected to the cluster of GIs (12-9). At Romont West, a second sediment disturbance between the Les Vaux and Harveng Soils (Fig. 46 and 47B) may correspond to the thermocast event 1 (TK-1, Antoine et la., 2016). Wood remains from the base at Nussloch were dated by 14C to ± 40 kyr cal. BP. Consequently, the TK-1 event can be narrowed between 43-40 ka. It is superimposed by loess, which acts as the parent material for the soil formation of the second phase.

135

136 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

The second pedogenetic phase is represented by a boreal soil characterized by a weak negative ΔGSD signal (Fig. 41) and a platy structure as a result of repeated freeze-thawing cycles (cf. Kadereit et al., 2013). OSL ages can be used to parallelize the Upper Brown Soil, Boreal Soil 4 and the Lohne Soil. At the reference site Schwalbenberg II, the Remagen-3 Soil was described as the most developed soil of the MPG (Schirmer et al., 2012). It shows no primary chalk and is the only soil with a platy structure, which is in agreement with the referred palaeosols. Fading corrected pIRIR225 and IRSL ages from above the Remagen-3 Soil (Frechen and Schirmer, 2011) and the stratigraphic situation indicate a correlation of the Remagen-3 Soil to the referred palaeosols (Fig. 45). This would suggest that the Sinzig Soils were formed during the early UPG which contradicts previous 14C ages generated from molluscs of the Sinzig Soils 2-3 (Figs. 36 and 45, Schirmer, 2012). Lang et al. (2003) mentioned that 14C ages from molluscs can be overestimated of up to 2000 years due to the incorporation of fossil carbonates. This may explain the difference to the obtained OSL ages. Unfortunately, other studies dealing with correlations of the Schwalbenberg II profile only focus on 14C ages and do not consider the fading corrected OSL ages (e.g. Schirmer, 2012; Kadereit and Wagner, 2013; Sauer et al., 2016).

The compiled OSL chronologies of the second pedogenetic phase corresponds with the end of the boreal forest (LEZ 7) and the subsequent change towards a steppe environment (Fig. 46, Sirocko et al., 2016). However, there is an ongoing debate, which GIs may correspond with this pedogenetic phase (cf. Kadereit et al., 2013; Antoine et al., 2016; Sauer et al., 2016). The onset of frequent flood layers after the GI-7 (Fig. 46), which is interpreted as a hint for a vegetation retreat and increasing erodibility, hamper the preservation conditions for this highly variable period. As a consequence, the precise timing of the soil formation and its correlation to Greenland interstadials is still a matter of debate whether it corresponds to GI 8-7 or GI 8-6 (Fig. 46, cf. Kadereit et al., 2013; Antoine et al., 2016; Sauer et al., 2016) and hence remains challenging. Especially within the context of the chronostratigraphy of the Lower Rhine Embayment (Fig. 36), our results advise to revise the correlation to GI for the second pedogenetic period and the transition to the UPG.

6.6.2.4 Upper Pleniglacial The transition from the MPG towards the UPG is characterized by the onset of dust accumulation traced by a homogenous ΔGSD signal and increasing grain sizes (Fig. 41, S6- 2_Fig. 1), which allow a separation into three phases. The same structure was also established for Belgium (morpho-sedimentary units D, E and F; Haesaerts et al., 2016) and Saxony (Unit III, IIb and IIa; Meszner et al., 2013). Following the OSL chronology from the LPS Ringen, the stages can be further correlated to the LEZ 6, 5 and 4 of the ELSA Vegetation stack (Fig. 46).

STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 137

6.6.2.4.1 Steppe phase (UPGa1) The first substage corresponds to the steppe environment of the LEZ 6 (Fig. 46). From the studied sites it is only preserved at Ringen. At other sites this stage is likely missing due to frequent hillslope erosion corresponding to a high frequency of flood events (Fig. 46). At Ringen, erosion was probably reduced due to the position close to a watershed and the presence of the moisture-capturing gyttia beyond the watershed. The steppe phase is characterized by the accumulation of well-sorted loess (S6-2_Fig. 1) and a slightly increased GSI (Fig. 41). The intercalated soils (G1, BS5) do not show a clear ΔGSD signal in the submicron range pointing to minimal chemical weathering and clay formation.

The parent material of the first tundra gley (G1, Kripp Layer, E0 Soil) overlying the youngest MPG soil was dated to 32-31 ka and the loess above to 30-29 ka (Fig. 45). Stratigraphic evidence and reliable OSL ages between Ringen and Schwalbenberg II strengthened this correlation (Fig. 46). The ages points to a tundra gley formation during the GI-5 and the subsequent deposition of loess during the cold-arid Heinrich-3 event (Fig. 46) with local maxima in the GSI at Ringen (Fig. 41) and fS at Schwalbenberg II (Schirmer, 2012). The onset of aeolian input corresponds well to the Heinrich-3 event in the Eifel dry maar cores (Sirocko et al., 2016).

The Boreal Soil 5 is the latest unit of the UPGa1 and shows a bisection with a slightly reduced CaCO3 content in the lower unit. Both horizons exhibit thin root channels coated by iron precipitation which points to a dense vegetation cover of herbs and grass. The submicron grains starts to decrease in the upper part accompanied by an increasing GSI and fS content (Fig. 41). This point to increasing aeolian activity simultaneously to the formation of the upper part. OSL ages from Ringen and Schwalbenberg II vary between 30 and 26 ka and allow for a correlation of the Boreal Soil 5 to the Sinzig Soils which contradicts the correlation of Schirmer (2012). A pedogenesis during the GI 4 and 3 is most likely. Comparable stratigraphic situations were documented at Nussloch (Antoine et al., 2001, 2009; Bibus et al., 2007; Gocke et al., 2014). The sequence also consists of a basal tundra gley, loess and a two-folded well expressed tundra gley (e.g. Antoine et al., 2009) or weak Bw horizons (Bibus et al., 2007). The GSI also remains on a low level and strongly increases at the onset of the tundra phase. The palaeosols probably corresponds to the Harveng Soil of the Belgian system. Both soils are characterized by a prismatic structure and large ice wedge cast. These features may have formed under the same climatic conditions as the Santerre cryoturbation horizon from Northern France (see Fig. 36), where the F2 ice wedge cast level reaching down from the top of the soil. OSL ages from Havrincourt clearly support this correlation (Fig. 45). The Datthausen Soil at the LPS Datthausen (Fig. 36, South Germany) dated to 26-28 ka also corresponds with the Boreal Soil 5 (Sauer et al., 2016).

At the top of the lower unit of the Boreal Soil 5, elevated chlorine content was observed by X-ray fluorescence analysis (S6-2_Fig. 4). High chlorine contents corresponds to high 137

138 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

concentrations of volcanic minerals in the heavy mineral assemblage of the Dehner maar core (pers. observation, P. Schulte). This could either point to a cryptotephra located between both units or an input of chlorine rich minerals. However, preliminary results from heavy mineral analysis of the coarse grain fraction do not confirm the presence of volcanic minerals. Further investigation of finer grain sizes are planned. However. the chlorine peak may be connected to the Wartgesberg Tephra dated by ice core tuning in the Eifel maars to 27.9 ± 2.0 ka between the GI-4 and GI-3 (Fig. 46, Förster and Sirocko, 2016).

6.6.2.4.2 Tundra phase (UPGa2) The environmental change from a steppe towards a tundra vegetation (LEZ 5) is accompanied by the maximum extent of Weichselian glaciation in Europe (e.g. Hughes et al. 2016; Böse et al., 2012). The aeolian activity reached its maximum indicated by the highest GSI values. At Ringen, two recognizable peaks are probably connected to the Greenland dust peaks according to OSL ages (Figs. 41 and 46). The decrease in the ΔGSD signal in the cSi/fS range from Romont East and Ringen points to more irregular shaped grains or a change in the parent material. One possible explanation is an increasing contribution from the exposed shelf of the North Sea and Channel (cf. Symkatz-Kloss, 2003; Antoine et al., 2009). The intercalated tundra gleys do not show a decreasing grain sizes as observed for several other LPS from Europe (e.g. Vandenberghe et al., 1998; Vandenberghe and Nugteren, 2001).

Tundra gleys of the UPGa2 cannot be correlated to GIs. However, Austin et al. (2012) have shown, that the period between the GI-3 and GI-2 was interrupted by increasing sea surface temperatures in the North-East Atlantic. Therefore, it was suggested by the authors to refine this period (Fig. 46). The weak tundra gleys from Ringen might correspond to phases of short term increases in NE Atlantic SSTs accompanied by moistening of Western and Central Europe. However, it is not possible to attribute the gley formation to single climate events the tundra gleys with a specific event recorded in other climate archives due to their short duration. In addition, it is a matter of ongoing debate if tundra gley formation is connected to interstadial conditions at all.

The most important marker of the UPG is the Eltville Tephra. The age results of Bayesian age modelling using OSL ages points to a deposition between 23.2 and 25.6 ka (Zens et al., 2017). This is in strong agreement with ages directly generated from the Eltville Tephra at Ringen (Zens et al., 2017) and distinct volcanic mineral peaks in the Dehner Maar core (Römer et al., 2016). The high GSI values (Ringen and Romont East) indicate strong aeolian activity during the eruption allowing the wide distribution over Western and Central Europe.

The UPGa2 terminates with a phase of extensive erosion which can be traced from Northern France towards the Lower Rhine Embayment and potentially into Saxony (Antoine et al., 2003; Schirmer, 2003; Meszner et al., 2013). The reworked sediments of the Kesselt Layer STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 139 were dated at Romont East to 25.0 ± 2.1 ka. Following the correlation of the overlying Nagelbeek Complex to the GI-2 (see Section 6.6.2.4.3), the erosional period corresponds to the biggest flood events recorded in the ELSA Flood Stack around 24.0, 23.6 and 23.5 ka (Brunck et al., 2016; Sirocko et al., 2016). They correspond to increased sea surface temperatures in the North-East Atlantic between 24.8 - 23.4 ka during the Heinrich-2 event (Austin et al., 2012). This promoted higher moisture transport and precipitation in the cold-arid tundra environment of Western and Central Europe.

6.6.2.4.3 Polar desert (UPGb) The UPGb is dominated by the deposition of homogeneous loess in a dry and cold environment (cf. Moine, 2014). The loess shows a finer grain size than the UPGa loess (S6- 2_Fig. 1). The characteristic ΔGSD pattern for the cSi/fS range of the tundra phase is not pronounced, indicating a change in the aeolian dynamics and probably the parent material. At Romont East and Garzweiler, the submicron particle content increases within the palaeosols without an expressed ΔGSD signal. In combination with the grain-size data (S6- 2_Fig. 1), this is an indication for the deposition of finer grains due to more dense vegetation cover in the source areas of deflatable material or cryogenic weathering. The Leonard Soil shows the same trend in the ΔGSD signal as the Nagelbeek Complex/E4 Soil. Römer el al. (2016) found evidence for a period of prevailing easterly winds after the GI-2 by heavy mineral analysis of the Dehner Maar core. This change in wind direction and possibly in source material could be the reason for the weak cSi/fs ΔGSD signal observed at Romont and Ringen. This assumption is strengthened by the same GSI pattern observed for the Dehner maar (Römer et al., 2016) and Garzweiler which allows for a temporal correlation between both records.

The boundary between the niveo-aeolian loess and homogeneous loess facies is characterized by an abrupt shift towards finer grain sizes at Romont East and Garzweiler S6- 2_Fig. 1). OSL ages from Romont East allows a solid correlation of the UPGa/b boundary between the frequent flood events and the onset of the GI-2 (Fig. 46). The Nagelbeek Complex/E4 pedogenesis corresponds to the GI-2. The correlation is confirmed by 14C ages of from the Nagelbeek Complex at Lixhe and Kesselt, and quartz OSL ages from Ostrau (Kreutzer et al., 2012b) and Holzweiler (Fischer, 2010). This allocation challenges the stratigraphic model from Belgium, which suggest a formation during the GI 3-4 (Fig. 36, Haesaerts et al., 2016).

The Leonard Soil was dated to ± 16-18 ka (Figs. 37, 41). There is no corresponding GI which may be connected to the calcaric Cambisol formation. This points to a decoupled climatic oscillation recorded in Greenland ice cores and Europe LPS by different signal patterns. However, in the ELSA Vegetation Stack, the occurrence of grass, moss and fungi between 15- 16 ka may be indicative for a short period of climate warming corresponding to the Leonard

139

140 | STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS

Soil. From Saxony, a Bw horizon is documented for the UPGb dated to 19.4 ± 2.6 ka – 17.5 ± 2.4 ka, which may correspond to the Leonard Soil.

6.7 Conclusions

This study presents quartz and pIRIR290 chronologies for four loess-palaeosol sequences (LPS) from Western and Central Europe. The comparison with OSL dated reference loess sections revealed consistent ages and stratigraphic features for important palaeosols and sedimentary sub sequences. Our dataset improves existing stratigraphic schemes in terms of chronology and synchronization with other geoarchives. The correlation of LPS to the Eifel- Laminated-Sediment-Archive (ELSA) suggests a strong connection between climatic fluctuations, vegetational changes and the genesis of loess records during the past 60 kyrs.

OSL ages from the Early Last Glacial humic horizons show an end of the latest pedogenesis of the Chernozem-like soils after the GI-19.2 or 19.1. The Lower Pleniglacial (LPG) can be divided into two sedimentary phases. The first phase (LPGa) started after the GI-19 (~70-69 ka) and is dominated by reworking of Eemian and Early Glacial soils and by slope erosion likely connected to higher sea surface temperatures in the NE Atlantic. The second phase is dominated by loess deposition and exhibits a weak palaeosol corresponding to the GI-18. The Middle Pleniglacial (MPG) can be structured into four environmental phases by the integrated perspective of stratigraphic evidence, grain size data and OSL ages. The first phase is characterized by abrupt climate warming leading to weak brownish loess with many crotovinas (~60-55 ka, GI-17 to 15, LEZ 9). It is followed by the first well-expressed period of pedogenesis corresponding to a spruce-hornbeam forest (GI-14 and 13, LEZ 8). The return to permafrost conditions is characteristic for the period between the end of GI-13 and the onset of GI-8 (boreal forest, LEZ 7). The timing of the second pedogenetic phase covers the GI-8 and probably GI-7 and 6. The precise demarcation remains challenging due to frequent phases of erosion occurring around the MPG/UPG boundary. The Upper Pleniglacial (UPG) is divided into three sedimentary substages (UPGa1, UPGb1 and UPGa) according to grain-size data and stratigraphic evidence. OSL ages allows to parallelize the stages to the steppe, tundra and polar desert of the LEZs 6, 5 and 4. Grain-size variations (GSI and ΔGSD) are very likely connected to vegetational changes and varying aeolian dynamics and availability of deflatable material.

Finally, the question arises if richly structured sequences such as Schwalbenberg II (MPG) represent the (super-)regional climatic and environmental evolution or if they are caused by a geomorphological setting which is highly sensitive to climatic changes and may only reflect the environmental evolution on a local scale. The common observation in many LPS of less palaeosols suggests that the landscape was more stable like than suggested by highly- structured sections and only major climatic deteriorations led to environmental response on regional and supra-regional scales. STUDY 3: OSL chronologies of palaeoenvironmental dynamics recorded by LPS | 141

141

142 | SYNTHESIS

7 Synthesis

This thesis summaries the result of three years of research on OSL dating, loess stratigraphy, age modelling and palaeoenvironmental reconstruction on five LPS from Western and Central Europe. For this purpose, sites from the Hesbaye, the Lower Rhine Embayment, the Lower/Middle Rhine transition and the Kraichgau were investigated forming a transect of terrestrial archives along a major trajectory of the anatomically modern humans from the Carpathian Basin towards northern Central and Western Europe. To meet the target of an integrated, proxy data based event-stratigraphical model, three consecutive studies were conducted, which are the central part of this thesis.

The inventory of the distribution, stratigraphy and luminescence chronology of LPS compiled in the first study (section 4) illustrates the importance of the geomorphological context and climatic conditions for the preservation of loess, if supra-regional comparisons are conducted.

(1) Loess and loess-like sediments are widely distributed in Western and Central Europe with varying thicknesses depending on the sediment availability (e.g. distance to larger river systems and the ice sheet), geomorphological setting and prevalent wind directions during phases of active aeolian accumulation. The temporal resolution recorded in the LPS can vary notably. Even in regions with an extensive and thick loess cover (e.g. Lower Rhine Embayment), sediments of the Last Glacial cycle can be very sparse (section 4.3.2 and 4.4.2).

(2) These variations are mainly reasoned by the large-scale and local topographic situation (section 4.2 and 4.5), which is controlled by the underlying geology (loose or hard bedrock). Periglacial conditions during glacial periods favoured erosive processes driven by slope wash, solifluction and/or deflation. They were more extensive in areas with a loose bedrock (in particular loess) and a flat topography (e.g. Lower Rhine Embayment), where incision into the underlying sediments is more feasible. An example representative for such conditions is the LPS Garzweiler-Borschemich (section 3.4 and 6.3.3). It shows the prevailing composition in the Lower Rhine Embayment with loess sediments predominantly originating from the UPGb; the youngest loess accumulation phase. In contrast, undulating landscapes provided more variable topographic situations allowing the preservation of well-expressed LPS, e.g. along slopes (Romont West and Frankenbach) or in watershed positions (Ringen). Here, the LPS Ringen exhibits the highest resolution of the sedimentary succession of the Last Glacial cycle due to the special geomorphological setting (section 3.1). Hence, it serves as the key site of this thesis.

(3) The geomorphological context in combination with periglacial processes during glacial periods highlights a major source of uncertainty of loess research in Western and Central Europe; frequent phases of erosion occur likely connected to an abrupt retreat of vegetation during climatic turnovers and fluctuating boundaries of continuous and discontinuous 7 SYNTHESIS | 143 permafrost (section 4.2 and 4.5). This challenges every stratigraphic correlation between LPS, not least because not every unconformity is visible in the field or even in proxy data (cf. missing grain size variation at the Eben Unconformity from Romont and Garzweiler, S6-2_Fig. 1). The usage of marker beds (e.g. palaeosols, volcanic ashes or unconformities) as stratigraphic tools to connect sedimentary units is a well-established scientific practice. However, as Löhr and Brunnacker (1974) already mentioned; the steering environmental factors (e.g. morphometry, moisture supply, geographic position) can result in a variety of sediment/soil properties and preservation conditions on small and large scale. This challenges the development of stratigraphic schemes, without reliable numerical age control.

(4) The chronology of many LPS is based upon luminescence dating (cf. Fig. 5). Despite the availability of data from a growing number of dated sections their quality can be subject to the methodological shortcomings laid out in section 2.1. However, such ages were frequently used to construct chronological frameworks for LPS and to correlate palaeosols to Greenland ice core data (section 2.3 and 6.2). The lack of precision and accuracy hamper the reliability of such correlation. Hence, it would be important to revise the chronologies of the reference sections.

The progress in OSL dating techniques have clearly improved the reliability, precision and accuracy of ages (section 2.1). In comparison with ‘out-of-date’ luminescence ages, the amount of reliable OSL ages and sites with high-resolution chronologies is comparatively low. In this context, marker beds become more important and can serve as chronological markers, if sufficient numerical age control is given. Ash layers are important marker beds for the construction of event-stratigraphies (e.g. Greenland ice core synchronisation, section 2.4.1), because they mark a time-synchronous event and of which occurrence and duration are assumed to be well-known.

The Eltville Tephra is a volcanic ash layer found in LPS from Western and Central Europe and is the target of the second study of this thesis (section 5). Marker beds such as the Eltville Tephra are commonly dated at multiple locations. Published luminescence ages from above and below the ET varies between 13.4-49.6 ka. To narrow the timing of the deposition, Bayesian age modelling was applied to a dataset compiled from reliable OSL ages bracketing the tephra (section 5.3.2). The calculated 1 standard deviation model age of 23.2-25.6 ka or 2 standard deviation model age of 24.3-24.4 ka, and the direct OSL ages from the tephra of 24.3

± 1.8 ka (pIRIR290) and 24.1 ± 1.9 ka (quartz) correspond to a discrete peak of volcanic minerals in the Dehner dry maar core around 24.3 ka. Combining these ages, an eruption of ± 24.2 ka is suggested likely corresponding to the second Greenland dust peak. Strong aeolian dynamics are proven by high values of the GSI at Ringen and Romont West (section 6.6.2). The integration of the ELSA Flood Stack strengthens the hypothesis of a connection between frequent flood layers recorded in the Eifel maar lakes around ~24-23 ka and the Eben Unconformity with its reworked sediments (Kesselt Layer). It is stratigraphically situated slightly above the ET and marks a landscape changing erosion event occurring from Northern

144 | SYNTHESIS

France towards the Lower Rhine Embayment, and possibly extends to the northern foreland of the Harz Mountains (see also section 4). The first attempt of constructing an integrated event-stratigraphy approach proposed in the second study highlights its potential as a reliable palaeoenvironmental model with a robust chronology for the Eben-Zone, which now serves as an entire ‘marker zone’.

The target of an integrated, proxy data based event-stratigraphical model is further extended for the entire Last Glacial cycle in the third study (section 6). Therefore, a total of

40 new quartz OSL and pIRIR290 ages are presented from five LPS from Western and Central Europe. In general, the good accordance between quartz and feldspar ages confirm the reliability of the established chronologies. The LPG sediments from Romont West are an exception. Here, pIRIR290 overestimates the burial age due to the incomplete bleaching during high-magnitude low-frequency slope wash erosion of Eemian and EG palaeosols (section 6.6.2.2). Reworked soil sediment is a common feature of the EG sequence and where subjected to problematic ages in other studies. Therefore, for reworked soil material, quartz should be taken for OSL dating purposes.

The LPS are then correlated by means of OSL ages, stratigraphic evidence and grain size data using the GSI and ΔGSD proxies. The proxy data show very comparable patterns in the different sections for the same time slices, which indicates comparable environmental conditions at the specific sites. Especially the ΔGSD signal is proved to be a suitable tool to distinguish between stratigraphical units (e.g. palaeosols of the MPG or reworked soil sediment of the LPG), but also for entire sequences corresponding to the climatic stages of the Last Glacial cycle (section 6.6.2, Fig. 411). As a next step, the presented LPS were compared with reference loess sections for specific time slices of the Last Glacial cycle (Fig. 45 and section 6.6.2). Comparable patterns in the fields of stratigraphy, OSL ages and proxy data were observed for LPS from Havrincourt (Northern France) until Dolni Vĕstonice (Czech Republic), which indicates similar environmental and climatic conditions on a larger scale. This accordance enables to improve the general chronologies of the climatic stages of the Last Glacial cycle. By further integrating Greenland ice core data and the ELSA stacks, a robust proxy data based event-stratigraphy is established.

The results enable a refinement of the chronostratigraphy for the boundaries of the major climatic stages and palaeosol formations. The EG/LPG boundary could be fixed to the end of the GI-20 or GI-19 between ~74-70 ka. The EG ends with a phase of intensive slope wash eroding the Eemian and EG soils. Within the reworked sediments, two pedogenetic phases are distinguishable and correlate by OSL ages most likely to the GI-18. However, it remains questionable if this short interstadial is responsible for the two well-expressed palaeosols. Here, it seems probable that the climatic conditions responsible for the soil formations in Europe where decoupled from the climatic system influencing the Greenland ice core records. 7 SYNTHESIS | 145

The MPG starts with a rapid thawing of permafrost and a weak pedogenesis characterised by biological activity with frequent crotovinas, probably during the GI-17 to GI-15. The remaining lithostratigraphic structure of the MPG is challenging, because only a few LPS show high-resolution sediment sequences of this phase. Mostly, only one or two pedogenetic phases are found. This may be interpreted as either frequent phases of erosion during climatic deterioration or extended phases of landscape stabilisation, which outlive short time cooling events. More intense multi-proxy analysis on MPG sequences are highly recommended to solve this open questions. However, stratigraphic records enables to distinguish between palaeosols formed before ~ 43 ka and after the Heinrich 4 event (~38 ka). The hiatus in between may be related to flood events recorded in the ELSA Flood Stack between 45-44 ka during a period with a more open vegetation cover.

Especially the revised subdivision of the UPG based on OSL ages, stratigraphic evidence and grain size data into three substages have important implications for the palaeoenvironmental evolution. They correspond to the steppe, tundra and polar desert landscape evolution zones proposed by the ELSA Stacks. The grain size variations indicates a strong connection of the grain sizes to the changing vegetation cover with a finer granularity during the steppe phase and a distinct coarsening in the tundra environment.

The results of this thesis point out both potentials of chronological research conducted on LPS and open challenges that deserve further consideration. The discontinuity of loess records due to erosion in a periglacial environment highlights the influence of the local geomorphological setting for the preservation and resolution of single LPS. Consequently, large scale climatic signals recorded in loess can be masked by local factors, such as topography or vegetation cover. This thesis shows the potential to identify supra-regional patterns by combining multiple LPS with robust OSL chronologies and grain size data. Robust age models are crucial for the inter-site connections as well as the correlation to other reference archives of climatic changes. In this context, marker beds are of major importance. The potential of Bayesian age modelling to narrow their timing is demonstrated for the Eltville Tephra. By the integration of Greenland ice core data into the improved (chrono-) stratigraphic model for LPS enables the identification of phases of coupled (corresponding signals) and decoupled atmospheric circulation patterns (different signals) between Greenland and Europe are identified. For the first time ELSA Stacks are included to a robust chronostratigraphic model of LPS to improve the understanding of the interplay between the vegetation cover and processes in the loess regions (accumulation, preservation and erosion). In summary, this dissertation introduces a new standard chronostratigraphy combining information from different archives and contributes to a better systematic understanding of the palaeoenvironmental evolution in Western and Central Europe.

On a local scale, further research on the LPS Ringen focussing on palaeopedology is highly recommended to extract deeper insights into the environmental evolution of the numerous palaeosols. Beside the high-resolution loess record, the gyttja provides an important archive,

146 | SYNTHESIS

where additional methods e.g. pollen analysis may be conducted. If the suggested timing for the formation of the gyttja during the MPG can be confirmed by OSL dating, the connection to the loess record may provide a very important combined geoarchive for the period of human occupation of the Rhine-Meuse area.

The presented proxy data based event-stratigraphy can be improved by the integration of new OSL ages from LPS investigated in future studies. The Bayesian age modelling approach may be applied to other marker beds if a sufficient number of ages bracketing the layer is available. Furthermore, it is highly recommended to enlarge the amount of palaeoenvironmental information of the stratigraphic model by the broad spectrum of biological and geochemical proxy data that can be extracted from loess sediments. Upper Palaeolithic in-situ findings in loess deposits can be included into the composite stratigraphic model presented here.

DANKSAGUNG | 147

Danksagung / Acknowledgment

In erster Linie gilt ein großer Dank meinem Doktorvater Prof. Dr. Frank Lehmkuhl. Bereits im Studium hat er meine Faszination für die Wissenschaft im Allgemeinen und die Physische Geographie im Speziellen mit seiner leidenschaftlichen Begeisterung entfacht. Bereits als Studentische Hilfskraft hat er mir die Möglichkeit gegeben wissenschaftlich zu arbeiten und meine Arbeit in den SFB806 einzubringen. Während der Promotionszeit hatte er stets ein offenes Ohr für Forschungsfragen und Sorgen, und gab mir darüber hinaus viele Freiheiten mich wissenschaftlich zu entfalten. Daher möchte ich gerade hierfür besonders bedanken, macht es doch den Kern wissenschaftlicher Tätigkeit aus.

Für die Betreuung in allen Belangen der Lumineszenz-Datierung gebührt ein großer Dank Dr. Nicole Klasen. Sie hat mir stets eine Kernkompetenz in der Wissenschaft vor Augen geführt: den kritischen Umgang mit Daten und deren Interpretation. Auf diese Weise hat sie mich stets angespornt nicht inne zu halten und sich mit einem Ergebnis nicht einfach zufrieden zu geben.

Dr. Christian Zeeden möchte ich für die herausragende gemeinsame Zeit im Gelände und auf den vielen Konferenzen danken. Seine konstruktive und positive Art hat einen ganz erheblichen Beitrag geleistet selbstbewusst am Ball zu bleiben.

Ein großer Dank gilt Philipp Schulte, Kollege und sehr guter Freund, der mich bei meiner Reise durch die geographischen Disziplinen schon seit dem ersten Semester begleitet. Immer uneigennützig, immer konstruktiv, immer da, ob für wissenschaftliche Fragen oder Phasen der Zerstreuung.

Ein ganz besonderer Dank gilt der wohl besten und angenehmsten Bürokollegin, die man sich vorstellen kann, Janina Bösken. Wir konnten stundenlang ruhig und konzentriert arbeiten, Musik hören, Kaffee/Tee trinken, lachen und uns motivieren und aufbauen, wenn es mal nicht so lief. Ich beglückwünsche jeden, der sich in Zukunft ein Büro mit ihr teilen darf.

Für viele theoretische und konzeptionelle Diskussionen über die Lumineszenz-Datierung und die Einführung in R gebührt Christoph Burow großer Dank. Jedes Treffen und jede Diskussion war eine große Bereicherung für mich.

Many thanks to Stéphane Pirson for his guidance and introduction in all the challenges of loess research in the field. An important part of this thesis would not have been possible without this cooperative collaboration.

Die vielen Geländearbeiten würde ich nicht zu den schönsten Erfahrungen der Promotionsjahre zählen, wenn ich sie nicht gemeinsam mit meiner Projektpartnerin Lydia Krauß hätte verbringen dürfen. Ob in kleiner Runde in der Stadtvilla am Harz oder mit Studentengruppen, es war mir immer eine Freude.

148 | DANKSAGUNG

Prof. Dr. Wolfgang Römer gebührt mein Dank für die vielen lehrreichen Diskussionen und die Hilfen bei Fragen aller Art von Statistik bis Schwerminerale.

Darüber hinaus möchte ich Dr. Anja Zander für die Hilfestellungen im Labor und die Auswertung der Dosimetrieproben herzlich danken.

Privat-Dozent Dr. Martin Kehl möchte ich herzlich für die Zweitbegutachtung meiner Dissertation danken.

Ohne unsere Anja Knops funktioniert Garnichts und so gebührt ihr mein Dank für alle die Unterstützung im administrativen Bereich mit Formularen, Abrechnungen aber auch stets gewährleisteter bester Kaffeeversorgung. All das ist aber nebensächlich angesichts der vielen schönen amüsanten Situationen an der ‚Theke‘. Vielen lieben Dank dafür!

Darüber hinaus möchte ich allen Kollegen am Lehrstuhl für Physische Geographie und Geoökologie für die stets sehr gute und freundschaftliche Atmosphäre danken. Auch für so manchem Tag auf dem Tivoli oder im „Zuhause“.

Ohne die vielen Studierenden und Hilfskräfte, die mich auf vielen Geländepraktika oder auch im Labor unterstützt haben, hätte diese Dissertation ohne Zweifel länger gedauert. Es waren wirklich tolle Zeiten mit euch in Achenheim, im Kraichgau und Schuld. Das werde ich wirklich vermissen.

All das wäre nicht möglich gewesen ohne Verena, die mir stets Quell der Freude und Halt in stürmischen Zeiten gewesen ist und auch weiter sein wird. Du zeigst mir Tag um Tag wofür es sich zu arbeiten und zu LEBEN lohnt.

Annette, René und Julien gebührt ein großes Dankeschön, dass ihr mich Woche um Woche auf andere Gedanken bringt, in dem wir gemeinsam in anderen, ferne Welten eintauchen. Das ist echte Distanz und Entspannung und möchte ich nicht mehr missen. Ebenso gelten Bennit und Dirk ein Dank, die trotz der Ferne immer für mich da waren und mich stets an die wichtigen Dinge im Leben erinnert haben.

Acknowledgements and contributions of the first study, chapter 4

Most of these studies were carried out in the context of the CRC 806 "Our way to Europe", subproject D1 "Analysis of Migration Processes due to Environmental Conditions between 40,000 and 14,000 a BP in the Rhine-Meuse Area", supported by the DFG (Deutsche Forschungsgemeinschaft). The authors would like to thank E. Eckmeier, P. Fischer, J. Protze, G. Stauch and C. Zeeden for several discussions and valuable contributions to improve the paper. In addition, we are grateful to H.-J. Ehrig, H. Lindner, V. Niedek and J. Walk for their help compiling the figures. In addition, we would like to thank two anonymous reviewers who helped a lot to improve the paper. DANKSAGUNG | 149

The lead author of the study is F. Lehmkuhl. He designed and wrote most parts of the paper. J. Zens was the author of chapter 4.4 and 4.4.1 and mainly contributed in cooperation with F. Lehmkuhl to chapter 4.5. JZ was also responsible for the loess distribution maps (Figs. 18, 22 and 24) and the figure comparing different stratigraphic schemes (Fig. 26). L. Krauß contributed especially for the regional setting of the foreland of the Harz Mountains and the descriptions of the selected LPS. H. Kels helped to compile loess sections including LPS from the Lower Rhine Embayment (see also supplementary material chapter 4). P. Schulte reviewed the article and contributed some new insights into the Grafenberg section. All authors significantly contributed to the interpretation of the data and provided significant input to the manuscript. All authors revised the manuscript.

Acknowledgements and contributions of the second study, chapter 5

We thank Stéphane Pirson for his guidance and helpful discussions during the field work in the chalk quarry Romont. In addition, we thank C.B.R. Romont and the Kettinger Tonwerke for the permission to investigate several loess exposures. We thank Philipp Schulte for helpful comments on an early version of the manuscript. Special thanks to an anonymous reviewer for a detailed and constructive review. This project is affiliated to the CRC 806 „Our way to Europe“, subproject D1. This work was supported by the German Science Foundation (DFG, grant number INST 216/602-2).

J. Zens is the lead author of the study. In cooperation with C. Zeeden, he developed the scientific concept. By the supervision of N. Klasen, J. Zens was responsible for OSL measurements and the data evaluation. C. Zeeden contributed all age calculations and wrote the chapters 5.4.2 and 5.5.1. W. Römer contributed the volcanic mineral content of the Dehner Maar drill core and contributed the statistic calculations of the ET age. Markus Fuchs provided unpublished OSL ages and revised the manuscript together with F. Lehmkuhl.

Acknowledgements and contributions of the third study, chapter 6

This project is affiliated to the CRC 806 „Our way to Europe“, subproject D1. We thank the German Science Foundation (DFG, grant number INST 216/602-2) for funding this project. We thank C.B.R. quarry Romont, Kettiger Thonwerke and RWE Power AG for the permission to investigate the exposed loess sections. Special thank is given to Mr. Riexinger from the ‘Untere Naturschutzbehörde Heilbronn’ for the field excursion and his guidance in the nature protection area Frankenbacher Gravel and the Landesamt für Umwelt, Messungen and Naturschutz for the permission to investigate the loess exposures in the nature protection area Frankenbacher Gravel. Additional thanks to Stephanie Scheffler for measuring the portable OSL samples.

150 | DANKSAGUNG

The lead author of the study is J. Zens. P. Schulte contributed grain-size data and conducted the calculation of the ΔGSD signal and wrote the chapters 6.4.3 and 6.5.2. He additionally provided the heatmaps of Figs. 40 and S6-2_Fig. 1. Most of the OSL measurements were conducted by J. Zens despite of samples from Garzweiler (N. Klasen) and Frankenbach (supported by D. Brill). The OSL data evaluation was jointly undertaken by J. Zens, N. Klasen, D. Brill and C. Burow. In addition, C. Burow contributed to the exploratory data analysis of the entire OSL-dataset and helped to compile Figure S6-2_Fig. 2. S. Pirson and P. Spagna contributed to all text passages related to the Romont loess section and to chapter 6.6.2. L. Krauß did the measurement and data processing of geochemical data. F. Lehmkuhl, E. Eckmeier, H. Kels and C. Zeeden contributed to the interpretation of the data and helped to improve the scientific reasoning. All authors revised the manuscript. REFERENCES | 151

References

Abdul Aziz, H., Di Stefano, A., Foresi, L.M., Hilgen, F.J., Iaccarino, S.M., Kuiper, K.F., Lirer, F., Salvatorini, G., Turco, E., 2008. Integrated stratigraphy and 40Ar/39Ar chronology of early Middle Miocene sediments from DSDP Leg 42A, Site 372 (Western Mediterranean). Palaeogeography, Palaeoclimatology, Palaeoecology 257, 123–138. doi:10.1016/j.palaeo.2007.09.013.

Adamiec, G., Aitken, M., 1998. Dose-rate conversion factors: update. Anc. TL 16, 37–50.

Ahorner, L., 1962. Untersuchungen zur quartären Bruchtektonik der Niederrheinischen Bucht. Eiszeitalter und Gegenwart (Journal of Quaternary Sciences), 13, 24-105.

Aitken, M.J., 1985. Thermoluminescence Dating. Academic, London.

Aitken, M.J., 1998. An Introduction to Optical Dating. Oxford University Press, Oxford.

Andersen, K.K., Svensson, A., Johnsen, S.J., Rasmussen, S.O., Bigler, M., Röthlisberger, R., Ruth, U., Siggaard-Andersen, M.-L., Peder Steffensen, J., Dahl-Jensen, D., Vinther, B.M., Clausen, H.B., 2006. The Greenland Ice Core Chronology 2005, 15–42 ka. Part 1: constructing the time scale. Quaternary Science Reviews, Critical Quaternary Stratigraphy 25, 3246–3257. doi:10.1016/j.quascirev.2006.08.002

Antoine, P., Rousseau, D.-D., Zöller, L., Lang, A., Munaut, A.-V., Hatté, C., Fontugne, M., 2001. High-resolution record of the last interglacial–glacial cycle in the Nussloch loess–palaeosol sequences, Upper Rhine Area, Germany. Quaternary International 76, 211–229.

Antoine, P., Catt, J., Lautridou, J.-P., Sommé, J., 2003. The loess and coversands of northern France and southern England. J. Quaternary Sci. 18, 309–318. doi:10.1002/jqs.750

Antoine, P., Rousseau, D.-D., Moine, O., Kunesch, S., Hatté, C., Lang, A., Tissoux, H., Zöller, L., 2009. Rapid and cyclic aeolian deposition during the Last Glacial in European loess: a high-resolution record from Nussloch, Germany. Quaternary Science Reviews 28, 2955– 2973. doi:10.1016/j.quascirev.2009.08.001

Antoine, P., Rousseau, D.-D., Degeai, J.-P., Moine, O., Lagroix, F., Kreutzer, S., Fuchs, M., Hatté, C., Gauthier, C., Svoboda, J., Lisá, L., 2013. High-resolution record of the environmental response to climatic variations during the Last Interglacial–Glacial cycle in Central Europe: the loess-palaeosol sequence of Dolní Věstonice (Czech Republic). Quaternary Science Reviews 67, 17–38. doi:10.1016/j.quascirev.2013.01.014

Antoine, P., Goval, E., Jamet, G., Coutard, S., Moine, O., Herisson, D., Auguste, P., Guerin, G., Lagroix, F., Schmidt, E., Robert, V., Debenham, N., Meszner, S., Bahain, J.-J., 2014. The Upper Pleistocene Loess Sequences of Havrincourt (pas-De-Calais, France): Stratigraphy, Palaeoenvironments, Geochronology and Human Occupations. Quaternaire 25, 321–368.

152 | REFERENCES

Antoine, P., Coutard, S., Guerin, G., Deschodt, L., Goval, E., Locht, J.-L., Paris, C., 2016. Upper Pleistocene loess-palaeosol records from Northern France in the European context: Environmental background and dating of the Middle Palaeolithic. Quaternary International, Middle Palaeolithic in North-West Europe: Multidisciplinary Approaches 411, Part A, 4–24. doi:10.1016/j.quaint.2015.11.036

Auclair, M., Lamothe, M., Huot, S., 2003. Measurement of anomalous fading for feldspar IRSL using SAR. Radiation Measurements, Proceedings of the 10th international Conference on Luminescence and Electron-Spin Resonance Dating (LED 2002) 37, 487–492. doi:10.1016/S1350-4487(03)00018-0

Austin, W.E.N., Hibbert, F.D., Rasmussen, S.O., Peters, C., Abbott, P.M., Bryant, C.L., 2012. The synchronization of palaeoclimatic events in the North Atlantic region during Greenland Stadial 3 (ca 27.5 to 23.3kyr b2k). Quaternary Science Reviews 36, 154–163. doi:10.1016/j.quascirev.2010.12.014

Austin, W.E.N., Hibbert, F.D., 2012. Tracing time in the ocean: a brief review of chronological constraints (60–8 kyr) on North Atlantic marine event-based stratigraphies. Quat. Sci. Rev., The INTegration of Ice core, Marine and TErrestrial records of the last termination (INTIMATE) 60,000 to 8000 BP 36, 28–37. doi:10.1016/j.quascirev.2012.01.015

Baales, M., Jöris, O., Street, M., Bittmann, F., Weninger, B., Wiethold, J., 2002. Impact of the Late Glacial Eruption of the Laacher See Volcano, Central Rhineland, Germany. Quaternary Research 58, 273–288. doi:10.1006/qres.2002.2379

Ballarini, M., Wallinga, J., Wintle, A.G., Bos, A.J.J., 2007. A modified SAR protocol for optical dating of individual grains from young quartz samples. Radiat. Meas. 42, 360–369. doi:10.1016/j.radmeas.2006.12.016

Bateman, M.D., Frederick, C.D., Jaiswal, M.K., Singhvi, A.K., 2003. Investigations into the potential effects of pedoturbation on luminescence dating. Quat. Sci. Rev., LED 2002 22, 1169–1176. doi:10.1016/S0277-3791(03)00019-2

Bayer, J., 1927. Der Mensch im Eiszeitalter. Franz Deuticke, Leipzig.

Bell, W.T., 1980. Alpha dose attenuation in quartz grains for thermoluminescence dating. Ancient TL 12: 4–8.

Beuselinck, L., Steegen, A., Govers, G., Nachtergaele, J., Takken, I., Poesen, J., 2000. Characteristics of sediment deposits formed by intense rainfall events in small catchments in the Belgian Loam Belt. Geomorphology 32, 69–82. doi:10.1016/S0169-555X(99)00068-9

Bibus, E., 1973. Ausbildung und Lagerungsverhältnisse quartärer Tuffvorkommen in der Wetterau. Notizblatt des Hessischen Landesamtes für Bodenforschung zu Wiesbaden 101, 346–361. REFERENCES | 153

Bibus, E., 1974. Das Quartärprofil im Braunkohlentagebau Heuchelheim (Wetterau) und seine vulkanischen Einschaltungen. Notizblatt des Hessischen Landesamtes für Bodenforschung zu Wiesbaden 102, 159–167.

Bibus , E., 1989. Paläoboden im mittleren Neckarbecken unter besonderer Berücksichtigung von Lößstratigraphie und Paläoboden.- Exkursionsführer, 8 Tagung des Arbeitskreises „Paläoboden“ der Deutschen Bodenkundlichen Gesellschaft, Heilbronn, 1-31.

Bibus, E., 2002. Zum Quartär im mittleren Neckarraum: Reliefentwicklung, Löß/Paläobodensequenzen, Paläoklima. Tübinger Geographische Studien, Reihe D 8, Geographisches Institut der Universität Tübingen.

Bibus, E., Semmel, A., 1977. Stratigraphische Leithorizonte im Würmlöß des Mittelrheingebietes. Geologisches Jahrbuch Hessen 105, 141–147.

Bibus, E., Frechen, M., Kösel, M., Rähle, W., 2007. Das jungpleistozäne Lössprofil von Nussloch (SW-Wand) im Aufschluss der Heidelberger Zement AG. Quaternary Science Journal 56, 227–255. doi:10.3285/eg.56.4.01.

Bibus, E.; Eberle, J., S. Mailänder, 2008. Stratigraphische Untersuchungen in quartären Deckschichten bei Frankenbach. In: Hansch, W. and Rosendahl, R.: 600.000 Jahre Zeitgeschichte am Neckar.- MUSEO 24, 54-67.

Blockley, S.P.E., Lane, C.S., Hardiman, M., Rasmussen, S.O., Seierstad, I.K., Steffensen, J.P., Svensson, A., Lotter, A.F., Turney, C.S.M., Bronk Ramsey, C., 2012. Synchronisation of palaeoenvironmental records over the last 60,000 years, and an extended INTIMATE1 event stratigraphy to 48,000 b2k. Quaternary Science Reviews, The INTegration of Ice core, Marine and TErrestrial records of the last termination (INTIMATE) 60,000 to 8000 BP 36, 2–10. doi:10.1016/j.quascirev.2011.09.017

Boch, R., Cheng, H., Spötl, R., Edwards, L., Wang, X., Häuselmann, Ph, 2011. NALPS: a precisely dated European climate record 120-60 ka. Climate of the Past 7, 1247-1259.

Bode, R., F. Lehmkuhl, V. Reinecke, A. Hilgers, V. Dresely, Radtke, U., 2003. Holozäne fluviale Geomorphodynamik und Besiedlungsgeschichte in einem kleinen Einzugsgebiet am nördlichen Harzrand. Eiszeitalter und Gegenwart (Journal of Quaternary Sciences) 53, 74- 93.

Boenigk, W., Weidenfeller, M., 1994. Die mittel- und oberpleistozäne Deckschichtenfolge im Naturschutzgebiet „Eiszeitliches Lößprofil“ in Koblenz-Metternich. Mainzer geowiss. Mitt., 23, 287-320.

Boenigk, W., Frechen, M., 1995. Lumineszenz-Datierungen an kolluvialen Sedimenten des Elsbachtales. Bonner Jahrbücher 195, 299-312.

154 | REFERENCES

Boenigk, W., Frechen, M., 2001. The loess record in sections at Koblenz–Metternich and Tönchesberg in the Middle Rhine Area. Quaternary International, Loess and Palaeosols: characteristics, stratigraphy, chronology 76–77, 201–209.

Boenigk, W., Frechen, M., 2006. The Pliocene and Quaternary fluvial archives of the Rhine system. Quaternary Science Reviews 25, 550–574.

Bogaard, P. v. d., 1995. 40Ar/39Ar ages of sanidine phenocrysts from Laacher See Tephra (12,900 yr BP): Chronostratigraphic and petrological significance. Earth and Planetary Science Letters 133, 163–174. doi:10.1016/0012-821X(95)00066-L

Bombien, H., 1987. Geologisch-petrographische Untersuchungen zur quartären (früh-Saale- zeitlichen) Flussgeschichte im nördlichen Harzvorland. Mitteilungen aus dem Geologischen Institut Univ. Hannover 26.

Böse, M., Lüthgens, C., Lee, J.R., Rose, J., 2012. Quaternary glaciations of northern Europe. Quat. Sci. Rev., Quaternary Glaciation History of Northern Europe 44, 1–25. doi:10.1016/j.quascirev.2012.04.017

Bøtter-Jensen, L., McKeever, S.W.S., Wintle, A.G., 2003. Optically Stimulated Luminescence Dosimetry. Elsevier, Amsterdam, 374.

Brennan, B.J., 2003. Beta doses to spherical grains. Radiation Measurements 37(4–5): 299–303, DOI 10.1016/S1350-4487(03)00011-8.

Brunck, H., Sirocko, F., Albert, J., 2016. The ELSA-Flood-Stack: A reconstruction from laminated sediments of the Eifel Maar structures during the last 60 000 years. J. of Global and Planetary Change. doi: 10.1016/j.gloplacha. 2015.12.003.

Brunnacker, K., 1967. Grundzüge einer Löß- und Bodenstratigraphie am Niederrhein. Eiszeitalter und Gegenwart, 18, 142-151.

Brunnacker, K., Boenigk, W., Hahn, Tillmanns, W., 1978. Das Jungpleistozän-Profil von Lommersum/Niederrheinische Bucht. Decheniana 131, 274-286.

Brunnacker, K., Hahn, J. 1978. Der jungpleistozäne Löß samt paläolithischer Kulturen in den Rheinlanden als Glied einer zeitlichen und räumlichen Faziesänderung, in: Nagl, H. (Ed.), Beiträge zur Quartär- und Landschaftsforschung. Festschrift zum 60. Geburtstag von Julis Fink, pp. 37-51.

Brunck, H., Sirocko, F., Albert, J., 2016. The ELSA – Flood – Stack: A reconstruction from the laminated sediments of Eifel Maar structures during the last 60 000 years. Global and Planetary Change (2016). doi:10.1016/j.gloplacha.2015.12.003 REFERENCES | 155

Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), IUSS Working Group WRB (Eds.), 2007. World Reference Base for Soil Resources 2006. Ein Rahmen für internationale Klassifikation, Korrelation und Kommunikation. Erstes Update 2007.

Buschbeck, H. M., Chun, H.-U., Dönig, R., Geßler, R., 1992. Thermoluminescence dating of loess horizons in Wiesbaden-Gräselberg and Wallertheim by the quartz-inclusion method. Quaternary Science Reviews 11, 19–23. doi:10.1016/0277-3791(92)90037-9

Bush, D.A., Feathers, J.K., 2003. Application of OSL single-aliquot and single-grain dating to quartz from anthropogenic soil profiles in the SE United States. Quat. Sci. Rev., LED 2002 22, 1153–1159. doi:10.1016/S0277-3791(03)00058-1

Buylaert, J.P., Murray, A.S., Thomsen, K.J., Jain, M., 2009. Testing the potential of an elevated temperature IRSL signal from K-feldspar. Radiat. Meas. 44, 560–565. doi:10.1016/j.radmeas.2009.02.007

Buylaert, J.-P., Jain, M., Murray, A.S., Thomsen, K.J., Thiel, C., Sohbati, R., 2012. A robust feldspar luminescence dating method for Middle and Late Pleistocene sediments. Boreas 41, 435–451. doi:10.1111/j.1502-3885.2012.00248.x

Chapot, M.S., Roberts, H.M., Duller, G.A.T., Lai, Z.P., 2012. A comparison of natural- and laboratory-generated dose response curves for quartz optically stimulated luminescence signals from Chinese Loess. Radiat. Meas. 47, 1045–1052. doi:10.1016/j.radmeas.2012.09.001

Colarossi, D., Duller, G.A.T., Roberts, H.M., Tooth, S., Lyons, R., 2015. Comparison of paired quartz OSL and feldspar post-IR IRSL dose distributions in poorly bleached fluvial sediments from South Africa. Quat. Geochronol., LED14 Proceedings 30, Part B, 233–238. doi:10.1016/j.quageo.2015.02.015

Constantin, D., Cameniţă, A., Panaiotu, C., Necula, C., Codrea, V., Timar-Gabor, A., 2015. Fine and coarse-quartz SAR-OSL dating of Last Glacial loess in Southern Romania. Quaternary International, Correlations of Quaternary Fluvial, Eolian, Deltaic and Marine Sequences: SEQS 2013 357, 33–43. doi:10.1016/j.quaint.2014.07.052

Cunningham, A.C., Wallinga, J., 2010. Selection of integration time intervals for quartz OSL decay curves. Quat. Geochronol. 5, 657–666. doi:10.1016/j.quageo.2010.08.004

Dansgaard, W., Johnsen, S.J., Clausen, H.B., Dahl-Jensen, D., Gundestrup, N.S., Hammer, C.U., Hvidberg, C.S., Steffensen, J.P., Sveinbjörnsdottir, A.E., Jouzel, J., Bond, G., 1993. Evidence for general instability of past climate from a 250-kyr ice-core record. Nature 364, 218–220.

Danzeglocke, U., Jöris, O., Weninger, B., 2007. CalPal-2007online CalPal-2007online, available at.

Davies, S.M., Abbott, P.M., Meara, R.H., Pearce, N.J.G., Austin, W.E.N., Chapman, M.R., Svensson, A., Bigler, M., Rasmussen, T.L., Rasmussen, S.O., Farmer, E.J., 2014. A North

156 | REFERENCES

Atlantic tephrostratigraphical framework for 130–60 ka b2k: new tephra discoveries, marine-based correlations, and future challenges. Quat. Sci. Rev., Dating, Synthesis, and Interpretation of Palaeoclimatic Records and Model-data Integration: Advances of the INTIMATE project (INTegration of Ice core, Marine and TErrestrial records, COST Action ES0907) 106, 101–121. doi:10.1016/j.quascirev.2014.03.024

De Boer, G.B., de Weerd, C., Thoenes, D., Goossens, H.W., 1987. Laser diffraction spectrometry: Fraunhofer diffraction versus Mie scattering. Part. Part. Syst. Charact. 4, 14– 19.

Delvoie, S., Pirson, S., Charlier, R., Collin, F., 2016. Etude da la séquence stratigraphique des loess de la carrière de Romont (Eben-Emael, Belgique) par une campagne géotechnique. Notae Praehistoricae 36, 5–21.

Diercke Weltatlas, 2008. Niederschläge im Jahr. 1. Auflage, Westermann, Braunschweig.

Dietrich, S., Seelos, K., 2010. The reconstruction of easterly wind directions for the Eifel region (Central Europe) during the period 40.3–12.9 ka BP. Clim. Past 6, 145–154. doi:10.5194/cp- 6-145-2010

Duller, G.A.T., 1991. Equivalent dose determination using single aliquots. Nuclear Tracks and Radiation Measurements 18, 371–378.

Duller, G.A.T., 1995. Luminescence dating using single aliquots: methods and applications. Radiation Measurements 24, 217–226.

Duller, G.A.T., 2008. Single-grain optical dating of Quaternary sediments: why aliquot size matters in luminescence dating. Boreas 37, 589–612. doi:10.1111/j.1502-3885.2008.00051.x

Duller, G.A.T., 2014. Luminescence Dating. In: Rink, W.J., Thompson, J. (Eds.), Encyclopedia of Scientific Dating Methods. Springer Netherlands, pp. 1–21. doi:10.1007/978-94-007-6326- 5_125-1

Duphorn, K., 1968. Ist der Oberharz im Pleistozän vergletschert gewesen? Eiszeitalter und Gegenwart (Journal of Quaternary Sciences) 19, 164-174.

Durcan, J.A., King, G.E., Duller, G.A.T., 2015. DRAC: Dose Rate and Age Calculator for trapped charge dating. Quaternary Geochronology 28, 54–61. doi:10.1016/j.quageo.2015.03.012

Ehlers, J., Eissmann L., Lippstreu L., Stephan H.-J., Wansa S., 2004. Pleistocene glaciation of North Germany, in: Ehlers J. and Gibbard P.L. (Eds.), Quaternary Glaciation – Extent and Chronology, Part I: Europe (Developments in Quaternary Sciences, 2). Elsevier, Amsterdam, pp. 135-146.

Ehlers, J., Grube, A., Stephan, H.J., Wansa, S., 2011. Pleistocene glaciation of North Germany – New results, in: Ehlers J., Gibbard P.L. and Hughes P.D. (Eds.), Quarternary Glaciation – REFERENCES | 157

Extent and Chronology. A Closer Look (Developments in Quaternary Sciences, 15). Elsevier, Amsterdam, pp. 149-162.

Eitel, B., 1989. Morphogenese im südlichen Kraichgau unter besonderer Berücksichtigung tertiärer und pleistozäner Decksedimente: ein Beitrag zur Landschaftsgeschichte Südwestdeutschlands. Geographisches Institut der Universität Stuttgart.

Feldmann, L., 1996. Das Quartär im nördlichen Harzvorland. Exkursionsführer. u. Veröff. GGW 197, 12-17.

Feldmann, L., 2002. Das Quartär zwischen Harz und Allertal mit einem Beitrag zur Landschaftsgeschichte im Tertiär. Habilitationsschrift TU Clausthal.

Fink, J., Haase, G., Ruske, R., 1977. Bemerkungen zur Lößkarte von Europe 1:2,5 Mio. Petermanns Geographische Mitteilungen 2 (77), 81–94.

Fischer, P., 2010. Zur mittel- und jungquartären Relief- und Bodenentwicklung der nordwestlichen Kölner Bucht – Detailuntersuchungen der lössbedeckten Mittelterrassenlandschaft. Diss. Univ. Köln. http://kups.ub.uni- koeln.de/volltexte/2010/3030/ (accessed 20.01.2016).

Fischer, P., Hilgers, A., Protze, J., Kels, H., Lehmkuhl, F., Gerlach, R., 2012. Formation and geochronology of Last Interglacial to Lower Weichselian loess/palaeosol sequences – case studies from the Lower Rhine Embayment, Germany. Eiszeitalter und Gegenwart (Quarternary Science Journal) 61, 48-63.

Förster, M.W., Sirocko, F., 2016. The ELSA tephra stack: Volcanic activity in the Eifel during the last 500,000 years. Glob. Planet. Change 142, 100–107. doi:10.1016/j.gloplacha.2015.07.012

158 | REFERENCES

Frechen, J., 1959. Der basaltische “Ausbläser” bei Kärlich (Neuwieder Becken) und die Verbreitung ihrer Tuffe. Fortschr. Geol. Rheinld. u. Westf., 4, 301-312.

Frechen, M., 1992. Systematic thermoluminescence dating of two loess profiles from the Middle Rhine Area (F.R.G.). Quaternary Science Reviews, Proceedings of the 6th International Specialist Seminar on Thermoluminescence and Electron Spin Resonance Dating 11, 93–101. doi:10.1016/0277-3791(92)90048-D.

Frechen, M., 1994. Thermolumineszens-Datierungen an Lössen des Tönchesberges aus der Osteifel. Eiszeitalter und Gegenwart (Quaternary Science Journal) 44, 79–93. doi:10.3285/eg.44.1.08.

Frechen, M., 1999. Upper Pleistocene loess stratigraphy in Southern Germany. Quaternary Science Reviews 18, 243–269. doi:10.1016/S0277-3791(98)00058-4.

Frechen, M., Boenigk, W., Weidenfeller, M. 1995. Chronostratigraphie des „Eiszeitlichen Lößprofils“ in Koblenz-Metternich. Mainzer Geowiss. Mitt. 24, 155-180.

Frechen, M., Preusser, F., 1996. Kombinierte Lumineszenz-Datierungen am Beispiel des Lössprofils Mainz-Weisenau. In A. Semmel, (Ed.). Pleistozäne und holozäne Böden aus Lößsubstraten am Nordrand der Oberrheinischen Tiefebene. Frankfurter geowissenschaftliche Arbeiten, D20, 53-66.

Frechen, M., van Vliet-Lanoë, B., van den Haute, P., 2001. The Upper Pleistocene loess record at Harmignies/Belgium - high resolution terrestrial archive of climate forcing. Palaeogeography, Palaeoclimatology, Palaeoecology 173, 175–195. doi:10.1016/S0031- 0182(01)00319-4.

Frechen, M., Oches, E.A., Kohfeld, K.E., 2003. Loess in Europe - mass accumulation rates during the Last Glacial Period. Quaternary Science Reviews, Loess and the Dust Indicators and Records of Terrestrial and Marine Palaeoenvironments (DIRTMAP) database 22, 1835– 1857. doi:10.1016/S0277-3791(03)00183-5.

Frechen, M., Schirmer, W., 2011. Luminescence Chronology of the Schwalbenberg II Loess in the Middle Rhine Valley. Quaternary Science Journal 60, 78–89. doi:10.3285/eg.60.1.05

French, H.M., 2007. The Periglacial Environment, third ed. John Wiley and Sons, Chichester.

Fuchs, M., Straub, J., Zöller, L., 2005. Residual luminescence signals of recent river flood sediments: a comparison between quartz and feldspar of fine-and coarse-grain sediments. Anc. TL 23, 25–30.

Fuchs, M., Lang, A., 2009. Luminescence dating of hillslope deposits—A review. Geomorphology, Luminescence dating in geomorphology 109, 17–26. doi:10.1016/j.geomorph.2008.08.025 REFERENCES | 159

Fuchs, M., Kreutzer, S., Rousseau, D.-D., Antoine, P., Hatté, C., Lagroix, F., Moine, O., Gauthier, C., Svoboda, J., Lisá, L., 2013. The loess sequence of Dolní Věstonice, Czech Republic: A new OSL-based chronology of the Last Climatic Cycle: Loess sequence of Dolní Věstonice, Czech Republic: OSL chronology. Boreas 42, 664–677. doi:10.1111/j.1502-3885.2012.00299.x

Galbraith, R.F., Roberts, R.G., Laslett, G.M., Yoshida, H., Olley, J.M., 1999. Optical Dating of Single and Multiple Grains of Quartz from Jinmium Rock Shelter, Northern Australia: Part I, Experimental Design and Statistical Models*. Archaeometry 41, 339–364. doi:10.1111/j.1475-4754.1999.tb00987.x

Gehrt, E., 1994. Die äolischen Sedimente im Bereich der nördlichen Lössgrenze zwischen Leine und Oker und deren Einflüsse auf die Bodenentwicklung. Diss. Univ. Göttingen.

Geological Survey of North Rhine-Westphalia, 2013. Geological Map of North Rhine- Westphalia 1:100,000 (GK100). Krefeld.

Gocke, M., Hambach, U., Eckmeier, E., Schwark, L., Zöller, L., Fuchs, M., Löscher, M., Wiesenberg, G.L.B., 2014. Introducing an improved multi-proxy approach for paleoenvironmental reconstruction of loess–paleosol archives applied on the Late Pleistocene Nussloch sequence (SW Germany). Palaeogeography, Palaeoclimatology, Palaeoecology 410, 300–315. doi:10.1016/j.palaeo.2014.06.006

Godfrey-Smith, D.I., Huntley, D.J., Chen, W.-H., 1988. Optical dating studies of quartz and feldspar sediment extracts. Quat. Sci. Rev. 7, 373–380. doi:10.1016/0277-3791(88)90032-7

Grahmann, R., 1932. Der Löss in Europa. Mitteilungen der Gesellschaft für Erkunde Leipzig 51, 5-24.

Guerin, G., Mercier, N., Adamiec, G., 2011. Dose-rate conversion factors: update. Anc. TL 29, 5–8.

Guihou, A., Pichat, S., Nave, S., Govin, A., Labeyrie, L., Michel, E., Waelbroeck, C., 2011. A late slowdown of the Atlantic Meridional overturning circulation during the Last Glacial inception: new constraints from sedimentary (231Pa/230Th). Earth and Planetary Science Letters 289, 520-529.

Gullentops, F., 1954. Contributions à la chronologie du Pléistocène et des forms du relief en Belgique. Mémoires de l’institut Géologiquw de l’Université de Louvain 18, 125-252.

Gullentops, F, Meijs, E.P.M., 2002: Loess sequences in Northern Haspengouw, Belgian Limburg. – In: Ikinger, A. & Schirmer, W. [eds.], Loess units and solcomplexes in the Niederrhein and Maas area. – Terra Nostra, 2002 (1): 80-91.

Haase, G., Lieberoth, I., Ruske, R., 1970. Sedimente und Paläoböden im Lößgebiet, in: Richter, H., Haase, G, Lieberoth, I., Ruske, R. (Eds.), Periglazial – Löß – Paläolithikum im

160 | REFERENCES

Jungpleistozän der Deutschen Demokratischen Republik. Petermanns Geographische Mitteilungen, Ergänzungsheft 274, 99-212.

Haase, D., Fink, J., Haase, G., Ruske, R., Pécsi, M., Richter, H., Altermann, M., Jäger, K.-D., 2007. Loess in Europe—its spatial distribution based on a European Loess Map, scale 1:2,500,000. Quaternary Science Reviews 26, 1301–1312. doi:10.1016/j.quascirev.2007.02.003

Haesaerts, P., 2004. Maisières-Canal (2000-2002): cadre stratigraphique. In: Miller, R., Haesaerts, P., Otte, M. (Eds.): L’atelier de taille aurignacien de Maisières-Canal (Belgique), vol. 110. Etudes et Recherches archéologiques de l’Université de Liège, 13-26.

Haesaerts, P., Juvigné, E., Kuyl, O., Mucher, H., Roebroeks, W., 1981. Compte rendu de l’excursion du 13 juin 1981, en Hesbaye et au Limbourg néerlandais, consacrée à la chronostratigraphie des loess du Pleistocène supérieur. Ann. Société Géologique Belg.

Haesaerts, P., Mestdagh, H., Bosquet, D., 1997. La séquence loessique de Remicourt (Hesbaye, Belgique). Notae Praehistoricae 17, 45-52.

Haesaerts, P., Mestdagh, H., Bosquet, D., 1999. The sequence of Remicourt (Hesbaye, Belgium): new insights on the pedo- and chronostratigraphy of the Rocourt soil. In: Baeteman, C. (Ed.), Quaternary Geology of Belgium: New Perspectives. Geologica Belgica 2 (1-2), 5-27.

Haesaerts, P., Mestdagh, H., 2000. Pedosedimentary evolution of the last interglacial and early glacial sequence in the European loess belt from Belgium to central Russia, Igitur. Geologie en Mijnbouw 79 2/3, 314-324.

Haesaerts, P., Pirson S., Meijs E. 2011a. Revised Lithostratigraphy of the Aeolian Loess Deposits. Addendum to F. Gullentops et al. 2001. ‘Quaternary Lithostratigraphic Units (Belgium)’. Geologica Belgica 4, 153-164.

Haesaerts, P., Pirson, S., Meijs, E., 2011b. Romont Group. In National Commission for Stratigraphy in Belgium (ed.), Quaternary lithostratigraphic units (Belgium). http://ncs.drupalgardens.com/quaternary/41-romont-group-0, accessed 09/05/2016.

Haesaerts, P., Damblon, F., Gerasimenko, N., Spagna, Pirson, S., 2016. The Late Pleistocene loess-palaeosol sequence of Middle Belgium. Quaternary International, 359-360, 25-43. doi: 10.1016/j.quaint.2016.02.012.

Hahn, J., 1972. Eine jungpaläolithische Feuerstelle aus Lommersum, Kreis Euskirchen. Rheinische Ausgrabungen 11, 56-80.

Hambach, U., Markovic S.B., Rolf, C., Zöller, L., 2008. Paläo- und umweltmagnetische Untersuchungen an Sedimenten der Bohrung Frankenbach 1. In: Hansch, W. and Rosendahl, R.: 600.000 Jahre Zeitgeschichte am Neckar.- MUSEO 24, 68-76. REFERENCES | 161

Händel, M., Simon, U., Einwögerer, T., Neugebauer-Maresch, C., 2009. Loess deposits and the conservation of the archaeological record - The Krems-Wachtberg example. Quaternary International, Loess in the Danube Region and Surrounding Loess Provinces: The Marsigli Memorial Volume 198, 46–50. doi:10.1016/j.quaint.2008.07.005.

Hatté, C., Fontugne, M., Rousseau, D.-D., Antoine, P., Zöller, L., Laborde, N.T., Bentaleb, I., 1998. δ13C variations of loess organic matter as a record of the vegetation response to climatic changes during the Weichselian. Geology 26, 583–586. doi:10.1130/0091- 7613(1998)026<0583:CVOLOM>2.3.CO;2

Hatté, C., Pessenda, L.C., Lang, A., Paterne, M., 2001. Development of accurate and reliable (super 14) C chronologies for loess deposits; application to the loess sequence of Nussloch (Rhine Valley, Germany). Radiocarbon 43, 611–618. doi:10.2458/azu_js_rc.43.3892.

Hatté, C., Guiot, J., 2005. Palaeoprecipitation reconstruction by inverse modelling using the isotopic signal of loess organic matter: application to the Nußloch loess sequence (Rhine Valley, Germany). Clim. Dyn. 25, 315–327. doi:10.1007/s00382-005-0034-3

Haverkamp, B., Beuker, Th., 1993. A palaeomagnetic study of maar-lake sediments from the Westeifel. Lect. Notes Earth Sci. 49, 349-365.

Hendl, M, 2002. Klima. In: Liedtke, H. and Marcinek, J. (Ed.). Physische Geographie Deutschlands, 18-126.

Henze, N., 1998. Kennzeichnung des Oberwürmlösses der Niederrheinischen Bucht, Kölner Forum für Geologie und Paläontologie. Geologisches Inst. der Univ. zu Köln, Köln.

Hilgen, F.J., Abdul Aziz, H., Krijgsman, W., Raffi, I., Turco, E., 2003. Integrated stratigraphy and astronomical tuning of the Serravallian and lower Tortonian at Monte dei Corvi (Middle–Upper Miocene, northern Italy). Palaeogeography, Palaeoclimatology, Palaeoecology 199, 229–264. doi:10.1016/S0031-0182(03)00505-4

Hilgen, F.J., Hinnov, L.A., Aziz, H.A., Abels, H.A., Batenburg, S., Bosmans, J.H.C., Boer, B. de, Hüsing, S.K., Kuiper, K.F., Lourens, L.J., Rivera, T., Tuenter, E., Wal, R.S.W.V. de, Wotzlaw, J.-F., Zeeden, C., 2014. Stratigraphic continuity and fragmentary sedimentation: the success of cyclostratigraphy as part of integrated stratigraphy. Geological Society, London, Special Publications 404, SP404.12. doi:10.1144/SP404.12

Hilgers, A., Gehrt, E., Janotta, A., Radtke, U., 2001. A contribution to the dating of the northern boundary of the Weichselian Loess Belt in Northern Germany by luminescence dating and pedological analysis. Quaternary International, Loess and Palaeosols: characteristics, stratigraphy, chronology 76–77, 191–200. doi:10.1016/S1040-6182(00)00102-6.

162 | REFERENCES

Holzkämper, A., 2013. Die älteste Besiedlung der Westfälischen Bucht am Ende der Weichseleiszeit, in: Baales, M., Pollmann, H.-O., Stapel, B. (Eds.), Westfalen in der Alt- und Mittelsteinzeit, pp. 115-117.

Holzkämper, J., Maier, A., 2012a. Neue Ergebnisse zur jungpaläolithischen Besiedlung Nordrhein-Westfalens. Archäologie im Rheinland, Vol. 2012, 52-54.

Holzkämper, J., Maier, A. 2012b. Neue Erkenntnisse zur Besiedlung Westfalens am Ende des späten Jungpaläolithikums. Archäologie in Westfalen-Lippe 2011, 52-54.

Holzkämper, J. M. A., Koch, I. 2014. Ergebnisse einer Suche nach Aurignacien- und Magdalénien-Fundstellen in Nordrhein-Westfalen, Archäologisches Korrespondenzblatt, in: Baales, M., Pollmann, H.-O., Stapel, B. (Eds.), Westfalen in der Alt- und Mittelsteinzeit, pp. 115-117.

Hövermann, J., 1974. Neue Befunde zur Pleistozänen Harz-Vergletscherung. Abhandlungen der Braunschweigischen wissenschaftlichen Gesellschaft 24, 31-52.

Hughes, A.L.C., Gyllencreuz, R., Lohne, Ø.S., Mangerud, J., Svendsen, J.I., 2016. The last Eurasian ice sheets – a chronological database and time-slice reconstruction, DATED-1. Boreas 45, 1-45. doi: 10.1111/bor.12142.

Huijzer, B., Vandenberghe, J., 1998. Climatic reconstruction of the Weichselian Pleniglacial in northwestern and Central Europe. J. Quaternary Sci. 13, 391–417. doi:10.1002/(SICI)1099- 1417(1998090)13:5<391::AID-JQS397>3.0.CO;2-6

Huntley, D.J., Godfrey-Smith, D.I., Thewalt, M.L.W., 1985. Optical dating of sediments. Nature 313, 105–107. doi:10.1038/313105a0

Huntley, D.J., Baril, M.R., 1997. The K content of the K-feldspars being measured in optical dating or in thermoluminescence dating. Ancient TL 15, 11–12.

Huntley, D.J., Lamothe, M., 2001. Ubiquity of anomalous fading in K-feldspars and the measurement and correction for it in optical dating. Can. J. Earth Sci. 38, 1093–1106. doi:10.1139/e01-013

Huot, S., Lamothe, M., 2012. The implication of sodium-rich plagioclase minerals contaminating K-rich feldspars aliquots in luminescence dating. Quat. Geochronol., 13th International Conference on Luminescence and Electron Spin Resonance Dating - LED 2011 Dedicated to J. Prescott and G. Berger 10, 334–339. doi:10.1016/j.quageo.2012.03.003

Hütt, G., Jaek, I., Tchonka, J., 1988. Optical dating: K-feldspars optical response stimulation spectra. Quat. Sci. Rev. 7, 381–385. doi:10.1016/0277-3791(88)90033-9

Ikinger, A., 1996. Bodentypen unter Laacher See-Tephra im Mittelrheinischen Becken und ihre Deutung. Mainzer Geowiss. Mitt. 25, 223-284. REFERENCES | 163

ISO 13320, 2009. Particle size analysis - Laser Diffraction Methods, part 1: general principles, Annex A: theoretical background of laser diffraction.

Jain, M., Singhvi, A.K., 2001. Limits to depletion of blue-green light stimulated luminescence in feldspars: implications for quartz dating. Radiation Measurements 33, 883–892. doi:10.1016/S1350-4487(01)00104-4

Janus, U., 1988. Löss der südlichen Niederrheinischen Bucht. Kölner Geographische Arbeiten 49.

Juvigné. E., 1992. Les formations cénozoïques de la carrière C.B.R. du Romont (Eben/Bassenge, Belgique). Annales de la Société Géologique de Belgique, 115, 159-165.

Juvigné, E., 1999. Téphrostratigraphie du Quaternaire en Belgique. Geologica Belgica 2, 73-87.

Juvigné, E., Semmel, A., 1981. Un tuf volcanique semblable à l’Eltviller Tuff dans les loess de Hesbaye (Belgique) et du Limbourg néerlandais. Quaternary Science Journal 31, 83–90. doi:10.3285/eg.31.1.08

Juvigné, E., Wintle, A.G., 1988. A New Chronostratigraphy of the Late Weichselian Loess Units in Middle Europe based on Thermoluminescence Dating. Quaternary Science Journal 38, 94–105. doi:10.3285/eg.38.1.09

Juvigné, E., Renard, F., 1992. Les terrasses de la Meuse de Liège à Maastricht. Annales de la Société géologique de Belgique 115, 167-186.

Juvigné, E., Tallier, E., Haesaerts, P., Pirson, S., 2008. Un nouveau stratotype du téphra de Rocourt dans la carrière de Romont (Eben/ Bassenge, Belgique). Quat. Rev. Assoc. Fr. Pour Létude Quat. 133–139. doi:10.4000/quaternaire.2742

Kadereit, A., Kind, C.-J., Wagner, G.A., 2013. The chronological position of the Lohne Soil in the Nussloch loess section – re-evaluation for a European loess-marker horizon. Quaternary Science Reviews 59, 67–86. doi:10.1016/j.quascirev.2012.10.026

Kadereit, A., Wagner, G.A., 2014. Geochronological reconsideration of the eastern European key loess section at Stayky in Ukraine. Clim. Past 10, 783–796. doi:10.5194/cp-10-783-2014

Kars, R.H., Wallinga, J., Cohen, K.M., 2008. A new approach towards anomalous fading correction for feldspar IRSL dating — tests on samples in field saturation. Radiat. Meas., Proceedings of the 15th Solid State Dosimetry (SSD15) 43, 786–790. doi:10.1016/j.radmeas.2008.01.021

Kels, H., 2007. Bau und Bilanzierung der Lössdecke am westlichen Niederrhein. Inaug.-Diss. Heinrich-Heine-Universität Düsseldorf, Düsseldorf.

164 | REFERENCES

Kels, H., Schirmer, W., 2010. Relation of loess units and prehistoric find density in the Garzweiler open-cast mine, Lower Rhine. Quaternary Science Journal 59, 59–65. doi:10.3285/eg.59.1-2.05

King, G.E., Sanderson, D.C.W., Robinson, R.A.J., Finch, A.A., 2014. Understanding processes of sediment bleaching in glacial settings using a portable OSL reader. Boreas 43, 955–972. doi:10.1111/bor.12078

Klasen, N., Fischer, P., Lehmkuhl, F., Hilgers, A., 2015a. Luminescence dating of loess deposits from the Remagen-Schwalbenberg site, Western Germany. Geochronometria 42.

Klasen, N., Loibl, C., Rethemeyer, J., Lehmkuhl, F., 2015b. Testing feldspar and quartz luminescence dating of sandy loess sediments from the Doroshivtsy site (Ukraine) against radiocarbon dating. Quaternary International (2015). doi:10.1016/j.quaint.2015.05.036

Klostermann, J., 1992. Das Quartär der Niederrheinischen Bucht. Geologisches Landesamt Nordrhein-Westfalen, Krefeld.

Krauß, L., Schmidt, G., Zierdt, M., Frühauf, M., 2013. Experimental determination of preferential flow paths used by infiltrated precipitation in a Haplic Chernozem and a Calcaric Cambisol from the Querfurter Platte. Hercynia N.F. 46, 21 – 40.

Krauß, L., Zens, J., Zeeden, C., Schulte, P., Eckmeier, E., Lehmkuhl, F. 2016. A Multi Proxy Analysis of two Loess-Palaeosol Sequences in the Northern Harz Foreland, Palaeogeography, Palaeoclimatology, Palaeoecology, doi: 10.1016/j.palaeo.2016.09.001

Krauß, L., Kappenberg, A., Zens, J., Kehl, M., Schulte, P., Zeeden, C., Eckmeier, E., Lehmkuhl, F., submitted. Reconstruction of Late Pleistocene Paleoenvironments in Southern Germany using two high-resolution loess-paleosol records. Submitted to Palaeogeography, Palaeoclimatology, Palaeoecology.

Krauß, L., 2017. Paleoenvironmental reconstruction of the last interglacial-glacial cycle of the Quaternary in Central Europe applying a multi-proxy approach investigating Loess- Paleosol Sequences. PhD thesis, submitted.

Kreutzer, S., Fuchs, M., Meszner, S., Faust, D., 2012a. OSL chronostratigraphy of a loess- palaeosol sequence in Saxony/Germany using quartz of different grain sizes. Quat. Geochronol. 10, 102–109. doi:10.1016/j.quageo.2012.01.004

Kreutzer, S., Schmidt, C., Fuchs, M.C., Dietze, M., Fischer, M., Fuchs, M., 2012b. Introducing an R package for luminescence dating analysis. Anc. TL 30, 1–8.

Kuiper, K.F., Deino, A., Hilgen, F.J., Krijgsman, W., Renne, P.R., Wijbrans, J.R., 2008. Synchronizing Rock Clocks of Earth History. Science 320, 500–504. doi:10.1126/science.1154339 REFERENCES | 165

Kukla, G., An, Z. 1989. Loess stratigraphy in Central China. Palaeogeography, Palaeoclimatology, Palaeoecology 72, 203-225.

Landesamt für Geologie und Bergwesen Sachsen-Anhalt (LAGB) (Ed.), 2006. Bodenbericht Sachsen-Anhalt 2006. Böden und Bodeninformationen in Sachsen-Anhalt. Mitteilungen zu Geologie und Bergwesen Sachsen-Anhalt 11.

Lang, A., Hatté, C., Rousseau, D.-D., Antoine, P., Fontugne, M., Zöller, L., Hambach, U., 2003. High-resolution chronologies for loess: comparing AMS 14C and optical dating results. Quaternary Science Reviews, LED 2002 22, 953–959. doi:10.1016/S0277-3791(03)00035-0

Lehmkuhl, F. 2016. Modern and past periglacial features in Central Asia and their implication for paleoclimate reconstructions. Progress in Physical Geography 40, 369-391.

Lehmkuhl, F., Wirtz, S., Falk, D., Kels, H., 2015. Geowissenschaftliche Untersuchungen zur Landschaftsentwicklung im Tagebau Garzweiler - LANU-Projekt 2012-2014, in: Kunow, J., Trier, M (Eds.), Archäologie im Rheinland 2014, 64-66.

Lehmkuhl, F., Zens, J., Krauß, L., Schulte, P., Kels, H., 2016. Loess-paleosol sequences at the northern European loess belt in Germany: Distribution, geomorphology and stratigraphy. Quaternary Science Reviews 153, 11–30. doi:10.1016/j.quascirev.2016.10.008

Lieberoth, I., 1963. Die jungpleistozänen Lösse Sachsens im Vergleich zu denen anderer Gebiete. Petermans Geographische Mitteilungen 106, 188-198.

Liedtke, H., 2002. Oberflächenformen. In: Liedtke, H. and Marcinek, J. (Ed.). Physische Geographie Deutschlands, 127-156.

Liritzis, I., Stamoulis, K., Papachristodoulou, C., Ioannides, K., 2013. A re-evaluation of radiation dose-rate conversion factors. Mediterr. Archaeol. Archaeom. 13, 1-15.

Löhr, H., 1987. Feldbeobachtungen zu Würmlößstratigraphie und Eltviller Tuff an der Mittelmosel sowie an der Munterley bei Gerolsstein. Trierer Zeitschrift für Geschichte und Kunst des Trierer Landes und seiner Nachbargebiete 50, 9–30.

Löhr, H., Brunnacker, K., 1974. Metternicher und Eltviller Tuff-Horizont im Würm-Löß im Mittel- und Niederrhein. Notizblatt des Hessischen Landesamtes für Bodenforschung zu Wiesbaden 102, 189–190.

Löscher, M., Zöller, L., 2001. Lössforschung im nordwestlichen Kraichgau. Jahresberichte und Mitteilungen des Oberrheinischen Geologischen Vereins, Neue Folge 83, 317-326.

Lomax, J., Fuchs, M., Preusser, F., Fiebig, M., 2012. Luminescence based loess chronostratigraphy of the Upper Palaeolithic site Krems-Wachtberg, Austria. Quaternary International. doi:10.1016/j.quaint.2012.10.037

166 | REFERENCES

Ludwig, P., Schaffernicht, E. J.,. Shao, Y., Pinto, J. G., 2016. Regional atmospheric circulation over Europe during the Last Glacial Maximum and its links to precipitation. J. Geophys. Res. Atmos. 121, 2130–2145. doi: 10.1002/2015JD024444.

Maier, A., Lehmkuhl, F., Ludwig, P., Melles, M., Schmidt, I., Shao, Y., Zeeden, C., Zimmermann, A., 2016. Demographic estimates of hunter–gatherers during the Last Glacial Maximum in Europe against the background of palaeoenvironmental data. Quat. Int. 425, 49–61. doi:10.1016/j.quaint.2016.04.009

Mania, D., 2003. Die Molluskenfauna der mittel- und jungquartären Ablagerungen von Lengefeld/Bad Kösen im Saaletal und ihre Aussage für Klimaentwicklung und Stratigraphie. Praehistoria Thuringica 9, 117-167.

Marković, S.B., Stevens, T., Kukla, G.J., Hambach, U., Fitzsimmons, K.E., Gibbard, P., Buggle, B., Zech, M., Guo, Z., Hao, Q., Wu, H., O’Hara Dhand, K., Smalley, I.J., Újvári, G., Sümegi, P., Timar-Gabor, A., Veres, D., Sirocko, F., Vasiljević, D.A., Jary, Z., Svensson, A., Jović, V., Lehmkuhl, F., Kovács, J., Svirčev, Z., 2015. Danube loess stratigraphy - Towards a pan- European loess stratigraphic model. Earth-Science Reviews 148, 228–258. doi:10.1016/j.earscirev.2015.06.005.

Martrat, B., Grimalt, J.O., Shackleton, N.J., de Abreu, L., Hutterli, M.A., Stocker, T.F., 2007. Four climate cycles of recurring deep and surface water destabilizations on the Iberian Margin. Science 317, 502-507.

Meijs, E.P.M., 2002. Loess stratigraphy in Dutch and Belgian Limburg. Quaternary Science Journal 51, 115–131. doi:10.3285/eg.51.1.08

Meijs, E.P.M., 2011. The Veldwezelt site (province of Limburg, Belgium): environmental and stratigraphical interpretations. Neth. J. Geosci. 90, 73–94. doi:10.1017/S0016774600001037

Meijs, E.P.M., Mücher, H., Ouwerkerk, G., Romein, A., Stoltenberg, H., 1983. Evidence of Presence of the Eltville Tuff Layer in Dutsch and Belgian Limbourg and the Consequences for the Loess Stratigraphy 33.

Meijs, E.P.M., Peer, P. van, Warrimont, J.P.L.M.N. de, 2013. Geomorphologic context and proposed chronostratigraphic position of Lower Palaeolithic artefacts from the Op de Schans pit near Kesselt (Belgium) to the west of Maastricht. Neth. J. Geosci. 91, 137–157. doi:10.1017/S0016774600001554

Mertz, D.F., Löhnertz, W., Nomade, S., Pereira, A., Prelević, D., Renne, P.R., 2015. Temporal– spatial evolution of low-SiO2 volcanism in the Pleistocene West Eifel volcanic field (West Germany) and relationship to upwelling asthenosphere. Journal of Geodynamics 88, 59– 79. doi:10.1016/j.jog.2015.04.002 REFERENCES | 167

Meszner, S., Kreutzer, S., Fuchs, M., Faust, D., 2013. Late Pleistocene landscape dynamics in Saxony, Germany: Paleoenvironmental reconstruction using loess-paleosol sequences. Quaternary International 296, 94–107. doi:10.1016/j.quaint.2012.12.040

Meyer, W., 2013. Geologie der Eifel. Schweizerbart, Stuttgart.

Meyer, B., Rohdenburg, H., 1982. Paläoböden der südniedersächsischen Lößgebiete. Geolog. Jahrb. F 14, 298-309.

Moine, O., 2014. Weichselian Upper Pleniglacial environmental variability in north-western Europe reconstructed from terrestrial mollusc faunas and its relationship with the presence/absence of human settlements. Quaternary International 337, 90–113. doi:10.1016/j.quaint.2014.02.030

Moine, O., Rousseau, D.-D., Antoine, P., 2008. The impact of Dansgaard–Oeschger cycles on the loessic environment and malacofauna of Nussloch (Germany) during the Upper Weichselian. Quaternary Research 70, 91–104. doi:10.1016/j.yqres.2008.02.010

Muhs, D.R., Bettis, A.E., 2003. Quaternary loess-Paleosol sequences as examples of climate- driven sedimentary extremes. Geol. Soc. Am. Spec. Pap. 370, 53–74. doi:10.1130/0-8137- 2370-1.53

Murray, A. S., Roberts, R. G., Wintle, A. G., 1997. Equivalent dose measurement using a single aliquot of quartz. Radiation Measurements 27, 171–184.

Murray, A.S., Wintle, A.G., 2000. Luminescence dating of quartz using an improved single- aliquot regenerative-dose protocol. Radiation Measurements 32, 57–73. doi:10.1016/S1350- 4487(99)00253-

Murray, A.S., Wintle, A.G., 2003. The single aliquot regenerative dose protocol: potential for improvements in reliability. Radiation Measurements, Proceedings of the 10th international Conference on Luminescence and Electron-Spin Resonance Dating (LED 2002) 37, 377–381. doi:10.1016/S1350-4487(03)00053-2

Murray, A.S., Thomsen, K.J., Masuda, N., Buylaert, J.P., Jain, M., 2012. Identifying well- bleached quartz using the different bleaching rates of quartz and feldspar luminescence signals. Radiat. Meas. 47, 688–695. doi:10.1016/j.radmeas.2012.05.006

Negendank, J.F.W., Brauer, A., Zolitschka, B. 1990. Die Eifelmaare als erdgeschichtliche Fallen und Quellen zur Rekonstruktion des Paläoenvironments. Mainzer geowiss. Mitt., 19, 235- 262.

Nigst, P.R., Haesaerts, P., Damblon, F., Frank-Fellner, C., Mallol, C., Viola, B., Götzinger, M., Niven, L., Trnka, G., Hublin, J.-J., 2014. Early modern human settlement of Europe north of the Alps occurred 43,500 years ago in a cold steppe-type environment. PNAS 201412201. doi:10.1073/pnas.1412201111.

168 | REFERENCES

Nilson, E., Köthe, R., Lehmkuhl, F., 2007. Categorising inconsistencies between national GIS data in Central Europe: Case studies from the country triangle of Belgium, the Netherlands and Germany. Applied GIS 3 10, 1-20.

Özer, M., Orhan, M., Işik, N.S., 2010. Effect of particle optical properties on size distribution of soils obtained by laser diffraction. Environ. Eng. Geosci. 16, 163–173.

Paas, W., 1962. Rezente und fossile Böden auf niederrheinischen Terrassen und deren Deckschichten. Eiszeitalter und Gegenwart (Quaternary Science Journal) 12, 165–230. doi:10.3285/eg.12.1.13

Paas, W., 1968a. Gliederung und Altersstellung der Lösse am Niederrhein. Fortschr. Geol. Rheinld. u. Westf. 16, 185-196.

Paas, W., 1968b. Stratigraphische Gliederung des Niederrheinischen Lösses und seiner fossilen Böden. Decheniana 121 (1/2), 9-38.

Paepe, R., Vanhoorne, R., 1967. The stratigraphy and paleobotany of the Late Pleistocene in Belgium (Memoirs of the Geological Survey of Belgium, 8). Aardkundige Dienst van België, Brussel.

Pécsi, M., Richter, G., 1996. Löss. Herkunft - Gliederung - Landschaften. Zeitschrift für Geomorphologie NF, Supplement-Bd. 98.

Pirrung, M., Büchel, G., Köppen, K.-H., 2007. Hochauflösende fluviolakustrine Sedimente des jüngeren Pleistozän aus dem Alfbachtal bei Gillenfeld (Westeifel) – erste Ergebnisse. Mainzer geowiss. Mitt., 35, 51-80.

Pirson, S., Flas, D., Abrams, G., Bonjean, D., Court-Picon, M., Di Modica, K., Draily, C., Damblon, F., Haesaerts, P., Miller, R., Rougier, H., Toussaint, M., Semal, P., 2012. Chronostratigraphic context of the Middle to Upper Palaeolithic transition: Recent data from Belgium. Quat. Int., Middle to Upper Paleolithic biological and cultural shift in Eurasia 259, 78–94. doi:10.1016/j.quaint.2011.03.035

Poser, H., 1948. Boden- und Klimaverhältnisse in Mitteleuropa während der Würmeiszeit. Erdkunde II (1-3), 53-67.

Pouclet, A., Juvigné, E., Pirson, S., 2008. The Rocourt Tephra, a widespread 90–74 ka stratigraphic marker in Belgium. Quaternary Research 70, 105–120. doi:10.1016/j.yqres.2008.03.010.

Pouclet, A., Juvigné, E., 2009. The Eltville Tephra, a Late Pleistocene Widespread Tephra Layer in Germany, Belgium and the Netherlands; Symptomatic Compositions of the Minerals. Geol. Belg. 12, 93–103. REFERENCES | 169

Prescott, J.R., Hutton, J.T., 1988. Cosmic ray and gamma ray dosimetry for TL and ESR. Int. J. Radiat. Appl. Instrum. Part Nucl. Tracks Radiat. Meas. 14, 223–227. doi:10.1016/1359- 0189(88)90069-6

Prescott, J.R., Hutton, J.T., 1994. Cosmic ray contributions to dose rates for luminescence and ESR dating: Large depths and long-term time variations. Radiat. Meas. 23, 497–500. doi:10.1016/1350-4487(94)90086-8

Preusser, F., Frechen, M. 1999. Chronostratigraphie der oberweichselzeitlichen Lößabfolge von Ockenfels (Mittelrhein). In: Becker-Haumann, R., Frechen, M (Eds.), Terrestrische Quartärgeologie, 68-80.

Preusser, F., Degering, D., Fuchs, M., Hilgers, A., Kadereit, A., Klasen, N., Krbetschek, M., Richter, D., Spencer, J.Q.G., 2008. Luminescence dating: basics, methods and applications. Eiszeitalt. Ggw. Sci. J. 57, 95–149. doi:10.3285/eg.57.1-2.5

Profe, J., Zolitschka, B., Schirmer, W., Frechen, M., Ohlendorf, C., 2016. Geochemistry unravels MIS 3/2 paleoenvironmental dynamics at the loess–paleosol sequence Schwalbenberg II, Germany. Palaeogeogr. Palaeoclimatol. Palaeoecol. 459, 537–551. doi:10.1016/j.palaeo.2016.07.022

Protze, J., 2014. Eine „Mensch gemachte Landschaft“ – Diachrone, geochemische und sedimentologische Untersuchungen an anthropogen beeinflussten Sedimenten und Böden der Niederrheinischen Lössbörde. Diss. Fakultät für Georessourcen und Materialtechnik, RWTH Aachen. http://darwin.bth.rwth-aachen.de/opus3/volltexte/2014/4906/ (accessed 10.12.2015).

Pye, K., 1995. The nature, origin and accumulation of loess. Quaternary Science Reviews, Aeolian Sediments in the Quaternary Record 14, 653–667. doi:10.1016/0277-3791(95)00047- X

Radtke, U., Janotta, A., Semmel, A., 1998. Lumineszenzdatierung des Lößprofils „Am Bingert“ (Wiesbaden), in: Radtke (Ed.), Lumineszenzdatierung äolischer Sedimente. Kölner Geographische Arb. 70, 59-64.

Rasmussen, S.O., Andersen, K.K., Svensson, A.M., Steffensen, J.P., Vinther, B.M., Clausen, H.B., Siggaard-Andersen, M.-L., Johnsen, S.J., Larsen, L.B., Dahl-Jensen, D., Bigler, M., Röthlisberger, R., Fischer, H., Goto-Azuma, K., Hansson, M.E., Ruth, U., 2006. A new Greenland ice core chronology for the last glacial termination. J. Geophys. Res. 111, D06102. doi:10.1029/2005JD006079

Rasmussen, S.O., Seierstad, I.K., Andersen, K.K., Bigler, M., Dahl-Jensen, D., Johnsen, S.J., 2008. Synchronization of the NGRIP, GRIP, and GISP2 ice cores across MIS 2 and palaeoclimatic implications. Quaternary Science Reviews 27, 18–28. doi:10.1016/j.quascirev.2007.01.016

170 | REFERENCES

Rasmussen, S.O., Bigler, M., Blockley, S.P., Blunier, T., Buchardt, S.L., Clausen, H.B., Cvijanovic, I., Dahl-Jensen, D., Johnsen, S.J., Fischer, H., Gkinis, V., Guillevic, M., Hoek, W.Z., Lowe, J.J., Pedro, J.B., Popp, T., Seierstad, I.K., Steffensen, J.P., Svensson, A.M., Vallelonga, P., Vinther, B.M., Walker, M.J.C., Wheatley, J.J., Winstrup, M., 2014. A stratigraphic framework for abrupt climatic changes during the Last Glacial period based on three synchronized Greenland ice-core records: refining and extending the INTIMATE event stratigraphy. Quaternary Science Reviews, Dating, Synthesis, and Interpretation of Palaeoclimatic Records and Model-data Integration: Advances of the INTIMATE project(INTegration of Ice core, Marine and TErrestrial records, COST Action ES0907) 106, 14–28. doi:10.1016/j.quascirev.2014.09.007

Razi Rad, M., 1976. Schwermineraluntersuchungen zur Quartär-Stratigraphie am Mittelrhein. Sonderveröffentlichung des Geologischen Instituts der Universität Köln 28.

Rees-Jones, J., 1995. Optical dating of young sediments using fine-grain quartz. Ancient TL 13, 9–14

Reinecke, V., 2006. Untersuchungen zur mittel- und jungpleistozänen Reliefentwicklung und Morphodynamik im nördlichen Harzvorland. Aachener Geographische Arbeiten 43.

Remy, H., 1960. Der Löß am unteren Mittel- und Niederrhein. Quaternary Science Journal 11, 107–120. doi:10.3285/eg.11.1.12.

Renssen, H., Vandenberghe, J., 2003. Investigation of the relationship between permafrost distribution in NW Europe and extensive winter sea-ice cover in the North Atlantic Ocean during the cold phases of the Last Glaciation. Quaternary Science Reviews 22, 209–223. doi:10.1016/S0277-3791(02)00190-7.

Rixhon, G., Braucher, R., Bourlès, D., Siame, L., Bovy, B., Demoulin, A., 2011. Quaternary river incision in NE Ardennes (Belgium)–Insights from 10Be/26Al dating of river terraces. Quat. Geochronol. 6, 273–284. doi:10.1016/j.quageo.2010.11.001

Rivera, T.A., Storey, M., Zeeden, C., Hilgen, F.J., Kuiper, K., 2011. A refined astronomically calibrated 40Ar/39Ar age for Fish Canyon sanidine. Earth and Planetary Science Letters 311, 420–426. doi:10.1016/j.epsl.2011.09.017

Rivera, T.A., Storey, M., Schmitz, M.D., Crowley, J.L., 2013. Age intercalibration of 40Ar/39Ar sanidine and chemically distinct U/Pb zircon populations from the Alder Creek Rhyolite Quaternary geochronology standard. Chemical Geology 345, 87–98. doi:10.1016/j.chemgeo.2013.02.021

Roberts, H.M., 2008. The development and application of luminescence dating to loess deposits: a perspective on the past, present and future. Boreas 37, 483–507. doi:10.1111/j.1502-3885.2008.00057.x REFERENCES | 171

Roberts, H.M., 2012. Testing Post-IR IRSL protocols for minimising fading in feldspars, using Alaskan loess with independent chronological control. Radiation Measurements 47, 716– 724. doi:10.1016/j.radmeas.2012.03.022

Rohdenburg, H., Meyer, B., 1966. Zur Feinstratigraphie und Paläopedologie des Jungpleistozäns nach Untersuchungen an südniedersächsischen und nordhessischen Lößproflen. Mitteilungen deutsche bodenkundliche Gesellschaft 5, 137-170.

Rohdenburg, H., Semmel, A., 1971. Bemerkungen zur Stratigraphie des Würm-Lösses im westlichen Mitteleuropa. Notizblatt des Hessischen Landesamtes für Bodenforschung zu Wiesbaden 99, 246–252.

Römer, W., Lehmkuhl, F., Sirocko, F., 2016. Late Pleistocene aeolian dust provenances and wind direction changes reconstructed by heavy mineral analysis of the sediments of the Dehner dry maar (Eifel, Germany). Global and Planetary Change 147, 25–39. doi:10.1016/j.gloplacha.2016.10.012

Rösner, U., 1990. Die Mainfränkischen Lößprovinz. Sedimentologische, pedologische und morphodynamische Prozesse der Lößbildung während des Pleistozäns in Mainfranken. Erlanger geogr. Arb., 51, Erlangen.

Rousseau, D.D., Antoine, P., Hatté, C., Lang, A., Zöller, L., Fontugne, M., Othman, D.B., Luck, J.M., Moine, O., Labonne, M., Bentaleb, I., Jolly, D., 2002. Abrupt millennial climatic changes from Nussloch (Germany) Upper Weichselian eolian records during the Last Glaciation. Quaternary Science Reviews 21, 1577–1582. doi:10.1016/S0277-3791(02)00034-3.

Rousseau, D.-D., Sima, A., Antoine, P., Hatté, C., Lang, A., Zöller, L., 2007. Link between European and North Atlantic abrupt climate changes over the last glaciation. Geophys. Res. Lett. 34, L22713. doi:10.1029/2007GL031716

Rousseau, D.-D., Antoine, P., Gerasimenko, N., Sima, A., Fuchs, M., Hatté, C., Moine, O., Zoeller, L., 2011. North Atlantic abrupt climatic events of the last glacial period recorded in Ukrainian loess deposits. Clim. Past 7, 221–234. doi:10.5194/cp-7-221-2011

Rousseau, D.-D., Derbyshire, E., Antoine, P., Hatté, C., 2013. Loess records – Europe, in: Mock, S.A.E.J. (Ed.), Encyclopedia of Quaternary Science, second ed. Elsevier, Amsterdam, pp. 606–619.

Royal Netherlands Meteorological Institute, 2013. Klimaattabel Maastricht, langjarige gemiddelden, tijdvak 1981–2010. Downloaded at the 15.2.2017.

172 | REFERENCES

Luminescence and Electron Spin Resonance Dating (LED 2008) 5, 299–305. doi:10.1016/j.quageo.2009.02.001

Sauer, D., Kadereit, A., Kühn, P., Kösel, M., Miller, C.E., Shinonaga, T., Kreutzer, S., Herrmann, L., Fleck, W., Starkovich, B.M., Stahr, K., 2016. The loess-palaeosol sequence of Datthausen, SW Germany: Characteristics, chronology, and implications for the use of the Lohne Soil as a marker soil. CATENA, Dan H. Yaalon Memorial Issue 146, 10–29. doi:10.1016/j.catena.2016.06.024

Scheffer, F., Schachtschabel, P., 1989. Lehrbuch der Bodenkunde. Stuttgart, Ferdinand Enke Verlag.

Schirmer, W., 1990. Schwalbenberg südlich Remagen, in: Schirmer, W. (Ed.), Rheingeschichte zwischen Mosel und Maas. Deuqua-Führer, 1: 105-108.

Schirmer, W., 1999. Kaltzeiten und Warmzeiten im Löß, in: Becker-Haumann, R., Frechen, M. (Eds.), Terrestrische Quartärgeologie, 81-100.

Schirmer, W., 2000. Eine Klimakurve des Oberpleistozäns aus dem rheinischen Löss. Eiszeitalter und Gegenwart (Quaternary Science Journal) 50, 25–49. doi:10.3285/eg.50.1.02.

Schirmer, W., 2002a. Lösse und Böden in Rheindahlen. GeoArchaeoRhein 5.

Schirmer, W., 2002b. Compendium of the Rhein loess sequence, in: Ikinger, A., Schirmer, W. (Eds.), Loess units and solcomplexes in the Niederrhein and Maas area. Terra Nostra, 2002 (1), pp. 8-23.

Schirmer, W., 2002c. Loess localities of the Niederrhein area, in: Ikinger, A., Schirmer, W. (Eds.), Loess units and solcomplexes in the Niederrhein and Maas area. Terra Nostra, 2002 (1), pp. 24-50.

Schirmer, W., 2003. Die Eben-Zone im Oberwürmlöss zwischen Maas und Rhein. In: Schirmer, W. (eds.): Landschaftsgeschichte im Europäischen Rheinland. GeoArchaeoRhein 4, 351– 416.

Schirmer, W., 2010. Interglacial complex and solcomplex. Central European Journal of Geosciences 2 (1), 32-40.

Schirmer, W., 2012. Rhine loess at Schwalbenberg II — MIS 4 and 3. Quaternary Science Journal 61, 32–47. doi:10.3285/eg.61.1.03

Schirmer, W., 2016. Late Pleistocene loess of the Lower Rhine. Quaternary International 411, Part A, 44–61. doi:10.1016/j.quaint.2016.01.034

Schlummer, M., Hoffmann, T., Dikau, R., Eickmeier, M., Fischer, P., Gerlach, R., Holzkämper, J., Kalis, A.J., Kretschmer, I., Lauer, F., Maier, A., Meesenburg, J., Meurers-Balke, J., Münch, U., Pätzold, S., Steininger, F., Stobbe, A., Zimmermann, A., 2014. From point to area: REFERENCES | 173

Upscaling approaches for Late Quaternary archaeological and environmental data. Earth- Science Reviews 131, 22–48. doi:10.1016/j.earscirev.2014.01.004

Schmidt, E.D., Semmel, A., Frechen, M., 2011a. Luminescence dating of the loess/palaeosol sequence at the gravel quarry Gaul/Weilbach, Southern Hesse (Germany). Quaternary Science Journal 60, 116–125. doi:10.3285/eg.60.1.08.

Schmidt, E.D., Frechen, M., Murray, A.S., Tsukamoto, S., Bittmann, F., 2011b. Luminescence chronology of the loess record from the Tönchesberg section: A comparison of using quartz and feldspar as dosimeter to extend the age range beyond the Eemian. Quat. Int., Loess in Eurasia 234, 10–22. doi:10.1016/j.quaint.2010.07.012

Schmidt, E.D., Tsukamoto, S., Frechen, M., Murray, A.S., 2014. Elevated temperature IRSL dating of loess sections in the East Eifel region of Germany. Quat. Int., ED@80: Loess in China and Europe - A Tribute to Edward Derbyshire 334–335, 141–154. doi:10.1016/j.quaint.2014.03.006

Schmidt, C., Sitlivy, V., Anghelinu, M., Chabai, V., Kels, H., Uthmeier, T., Hauck, T., Băltean, I., Hilgers, A., Richter, J., Radtke, U., 2013. First chronometric dates (TL and OSL) for the Aurignacian open-air site of Româneşti-Dumbrăviţa I, Romania. Journal of Archaeological Science 40, 3740–3753. doi:10.1016/j.jas.2013.04.003.

Schmitz, R.W., Thissen, J., 1997. Rheindahlen - ein Fundplatz des Micoquien im Niederrheinischen Tiefland. Archäologie im Rheinland 1997, 17–18.

Schönhals, E., 1959. Klima, äolische Sedimentation und Bodenbildung während der Eiszeit in Hessen. Z. deutsch. Geol. Ges. 111, 251-253.

Schönhals, E., Rohdenburg, H., Semmel, A., 1964. Ergebnisse neuerer Untersuchungen zur Würmlöß-Gliederung in Hessen. Quaternary Science Journal 15, 199–206. doi:10.3285/eg.15.1.15

Schmidt, S., 2014. The continuity of the loess record Ginseldorf - defined through luminescence dating. Unpublishes MSc thesis, Department of Geography, JLU Gießen.

Schulte, P., Lehmkuhl, F., Steininger, F., Loibl, D., Lockot, G., Protze, J., Fischer, P., Stauch, G., 2016. Influence of HCl pretreatment and organo-mineral complexes on laser diffraction measurement of loess-paleosol-sequences. Catena 137, 392–405.

Schulte, P., Lehmkuhl, F., (2017). The difference of two laser diffraction patterns as an indicator for post-depositional grain size reduction in loess-paleosol sequences. Palaeogeography, Palaeoclimatology, Palaeoecology, in press.

Seelos, K., Sirocko, F., 2005. RADIUS—Rapid particle analysis of digital images by ultra-high- resolution scanning of thin sections. Sedimentology 52, 669-681. doi:10.1111/j.1365- 3091.2005.00715.x.

174 | REFERENCES

Seelos, K., Sirocko, F., Dietrich, S., 2009. A continuous high-resolution dust record for the reconstruction of wind systems in central Europe (Eifel, Western Germany) over the past 133 ka. Geophys. Res. Lett. 36, L20712. doi:10.1029/2009GL039716

Seierstad, I.K., Abbott, P.M., Bigler, M., Blunier, T., Bourne, A.J., Brook, E., Buchardt, S.L., Buizert, C., Clausen, H.B., Cook, E., Dahl-Jensen, D., Davies, S.M., Guillevic, M., Johnsen, S.J., Pedersen, D.S., Popp, T.J., Rasmussen, S.O., Severinghaus, J.P., Svensson, A., Vinther, B.M., 2014. Consistently dated records from the Greenland GRIP, GISP2 and NGRIP ice cores for the past 104 ka reveal regional millennial-scale δ18O gradients with possible Heinrich event imprint. Quaternary Science Reviews, Dating, Synthesis, and Interpretation of Palaeoclimatic Records and Model-data Integration: Advances of the INTIMATE project(INTegration of Ice core, Marine and TErrestrial records, COST Action ES0907) 106, 29–46. doi:10.1016/j.quascirev.2014.10.032

Semmel, A., 1967. Neue Fundstellen von vulkanischem Material in hessischen Lössen. Notizblatt des Hessischen Landesamtes für Bodenforschung zu Wiesbaden 95, 104–108.

Semmel, A., 1968. Studien über den Verlauf jungpleistozäner Formung in Hessen. Frankfurter Geographische Hefte 45, 1-133.

Semmel, A., Stäblein, G., 1971. Zur Entwicklung quartärer Hohlformen in Franken 22, 23–34. doi:10.3285/eg.22.1.03

Semmel, A., 1989. The importance of loess in the interpretation of geomorphological processes and for dating in the federal Republic of Germany. Catena Suppl. 15,179-188.

Semmel, A., 1998. Zur paläopedologischen Gliederung des älteren Würmlösses in Mitteleuropa. Mitteilungen Dtsch. Bodenkd. Ges. 449–452.

Semmel, A., 1999. Die paläopedologische Gliederung des älteren Würmlösses in Mitteleuropa - erörtert an Beispielen aus dem Rhein-Main-Gebiet. Zeitschrift für geologische Wissenschaften 27, 121-133.

Semmel, A., Terhorst, B., 2010. The concept of the Pleistocene periglacial cover beds in central Europe: a review. Quaternary International 222, 120–128.

Sima, A., Rousseau, D.-D., Kageyama, M., Ramstein, G., Schulz, M., Balkanski, Y., Antoine, P., Dulac, F., Hatté, C., 2009. Imprint of North-Atlantic abrupt climate changes on western European loess deposits as viewed in a dust emission model. Quaternary Science Reviews 28, 2851–2866. doi:10.1016/j.quascirev.2009.07.016

Sirocko, F., Seelos, K., Schaber, K., Rein, B., Dreher, F., Diehl, M., Léhne, R., Jäger, K., Krbetschek,M., Degering, D., 2005. A Late Eemian aridity pulse in central Europe during the last glacial inception. Nature 436, 833–836. REFERENCES | 175

Sirocko, F., Dietrich, S., Veres, D., Grootes, P.M., Schaber-Mohr, K., Seelos, K., Nadeau, M.-J., Kromer, B., Rothacker, L., Röhner, M., Krbetschek, M., Appleby, P., Hambach, U., Rolf, C., Sudo, M., Grim, S., 2013. Multi-proxy dating of Holocene maar lakes and Pleistocene dry maar sediments in the Eifel, Germany. Quaternary Science Reviews 62, 56–76. doi:10.1016/j.quascirev.2012.09.011

Sirocko, F., 2016. The ELSA - Stacks (Eifel-Laminated-Sediment-Archive): An introduction. Global and Planetary Change 142, 96–99. doi:10.1016/j.gloplacha.2016.03.011

Sirocko, F., Knapp, H., Dreher, F., Förster, M.W., Albert, J., Brunck, H., Veres, D., Dietrich, S., Zech, M., Hambach, U., Röhner, M., Rudert, S., Schwibus, K., Adams, C., Sigl, P., 2016. The ELSA-Vegetation-Stack: Reconstruction of Landscape Evolution Zones (LEZ) from laminated Eifel maar sediments of the last 60,000 years. Global and Planetary Change 142, 108–135. doi:10.1016/j.gloplacha.2016.03.005

Sitlivy, V., Chabai, V., Anghelinu, M., Uthmeier, T., Kels, H., Hilgers, A., Schmidt, C., Niţă, L., Băltean, I., Veselsky, A. Hauck, T., 2012. The earliest Aurignacian in Romania: New investigations at the open air site of Româneşti-Dumbrăviţa I (Banat). Quartär 59, 85-130.

Skinner, L.C., 2008. Revisiting the absolute calibration of the Greenland ice-core age-scales*. Clim Past 4, 295–302. doi:10.5194/cp-4-295-2008

Slattery, M.C., Burt, T.P., 1997. Particle size characteristics of suspended sediment in hillslope runoff and stream flow. Earth Surf. Process. Landf. 22, 705–719. doi:10.1002/(SICI)1096- 9837(199708)22:8<705::AID-ESP739>3.0.CO;2-6

Smalley, I., O’Hara-Dhand, K., Wint, J., Machalett, B., Jary, Z., Jefferson, I., 2009. Rivers and loess: The significance of long river transportation in the complex event-sequence approach to loess deposit formation. Quaternary International 198, 7–18. doi:10.1016/j.quaint.2008.06.009.

Smalley, I., Marković, S.B., Zorica, S., 2011. Loess is [almost totally formed by] the accumulation of dust. Quaternary International 240, 4-11.

Smedley, R.K., Duller, G.A.T., Pearce, N.J.G., Roberts, H.M., 2012. Determining the K-content of single-grains of feldspar for luminescence dating. Radiat. Meas., Proceedings of the 13th International Conference on Luminescence and Electron Spin Resonance Dating, 10–14 July, 2011, Toruń, Poland 47, 790–796. doi:10.1016/j.radmeas.2012.01.014

Smykatz-Kloss, B., 2003. Die Lößvorkommen des Pleiser Hügellandes bei Bonn und von Neustadt, Wied sowie der Picardie: mineralogisch-geochemische und geomorphologische Charakterisierung, Verwitterungs-Beeinflussung und Herkunft der Lösse. Diss. Bonn.

Spooner, N.A., 1992. Optical dating: Preliminary results on the anomalous fading of luminescence from feldspars. Quaternary Science Reviews, Proceedings of the 6th

176 | REFERENCES

International Specialist Seminar on Thermoluminescence and Electron Spin Resonance Dating 11, 139–145. doi:10.1016/0277-3791(92)90055-D

Spooner, N.A., 1994. The anomalous fading of infrared-stimulated luminescence from feldspars. Radiation Measurements 23, 625–632. doi:10.1016/1350-4487(94)90111-2

Sprafke, T., Obreht, I., 2015. Loess: Rock, sediment or soil – What is missing for its definition? Quaternary International 399, 198-207. doi:10.1016/j.quaint.2015.03.033.

Stevens, T., Thomas, D.S.G., Armitage, S.J., Lunn, H.R., Lu, H., 2007. Reinterpreting climate proxy records from late Quaternary Chinese loess: A detailed OSL investigation. Earth- Science Reviews 80, 111-136.

Stevens, T., Marković, S.B., Zech, M., Hambach, U., Sümegi, P., 2011. Dust deposition and climate in the Carpathian Basin over an independently dated last glacial–interglacial cycle. Quaternary Science Reviews 30, 662–681. doi:10.1016/j.quascirev.2010.12.011

Sun, Y., Clemens, S.C., An, Z., Yu, Z., 2006. Astronomical timescale and palaeoclimatic implication of stacked 3.6-Myr monsoon records from the Chinese Loess Plateau. Quaternary Science Reviews 25, 33–48. doi:10.1016/j.quascirev.2005.07.005.

Svensson, A., Andersen, K.K., Bigler, M., Clausen, H.B., Dahl-Jensen, D., Davies, S.M., Johnsen, S.J., Muscheler, R., Rasmussen, S.O., Röthlisberger, R., Peder Steffensen, J., Vinther, B.M., 2006. The Greenland Ice Core Chronology 2005, 15–42 ka. Part 2: comparison to other records. Quaternary Science Reviews, Critical Quaternary Stratigraphy 25, 3258–3267. doi:10.1016/j.quascirev.2006.08.003

Terhorst, B., Sedov, S., Sprafke, T., Peticzka, R., Meyer-Heintze, S., Kühn, P., Solleiro Rebolledo, E., 2015. Austrian MIS 3/2 loess–palaeosol records - Key sites along a west–east transect. Palaeogeography, Palaeoclimatology, Palaeoecology 418, 43–56. doi:10.1016/j.palaeo.2014.10.020

Teschmer, A., Rolf, C., Weidenfeller, M., 2006. Lumineszenz-Chronologie und paläomagnetische Untersuchungen des Lößprofils Alsheim (Mainzer Becken). Mainzer geowiss. Mitt., 34, 113-134.

Thissen, J., 2006. Die paläolithischen Freilandstationen von Rheindahlen im Löss zwischen Maas und Niederrhein. Rheinische Ausgrabungen 59.

Thiel, C., Buylaert, J.-P., Murray, A., Terhorst, B., Hofer, I., Tsukamoto, S., Frechen, M., 2011a. Luminescence dating of the Stratzing loess profile (Austria) - Testing the potential of an elevated temperature post-IR IRSL protocol. Quat. Int. 234, 23–31. doi:10.1016/j.quaint.2010.05.018 REFERENCES | 177

Thiel, C., Buylaert, J.-P., Murray, A.S., Terhorst, B., Tsukamoto, S., Frechen, M., Sprafke, T., 2011b. Investigating the chronostratigraphy of prominent palaeosols in Lower Austria using post-IR IRSL dating. Quat. Sci. J. 60, 137–152. doi:10.3285/eg.60.1.10

Thome, K. N., 1998. Einführung in das Quartär. Springer, Berlin.

Thomsen, K.J., Murray, A.S., Jain, M., Bøtter-Jensen, L., 2008. Laboratory fading rates of various luminescence signals from feldspar-rich sediment extracts. Radiation Measurements 43, 1474–1486. doi:10.1016/j.radmeas.2008.06.002

Timar-Gabor, A., Vandenberghe, D.A.G., Vasiliniuc, S., Panaoitu, C.E., Panaiotu, C.G., Dimofte, D., Cosma, C., 2011. Optical dating of Romanian loess: A comparison between silt-sized and sand-sized quartz. Quaternary International 240, 62–70. doi:10.1016/j.quaint.2010.10.007

Timar-Gabor, A., Wintle, A.G., 2013. On natural and laboratory generated dose response curves for quartz of different grain sizes from Romanian loess. Quat. Geochronol. 18, 34– 40. doi:10.1016/j.quageo.2013.08.001

Timar-Gabor, A., Constantin, D., Buylaert, J.P., Jain, M., Murray, A.S., Wintle, A.G., 2015. Fundamental investigations of natural and laboratory generated SAR dose response curves for quartz OSL in the high dose range. Radiat. Meas. doi:10.1016/j.radmeas.2015.01.013

Tissoux, H., Valladas, H., Voinchet, P., Reyss, J.L., Mercier, N., Falguères, C., Bahain, J.-J., Zöller, L., Antoine, P., 2010. OSL and ESR studies of Aeolian quartz from the Upper Pleistocene loess sequence of Nussloch (Germany). Quaternary Geochronology, 12th International Conference on Luminescence and Electron Spin Resonance Dating (LED 2008) 5, 131–136. doi:10.1016/j.quageo.2009.03.009

Tukey, J.W., 1977. Exploratory data analysis. Addison-Wesely, Bosten.

Uthmeier, T., 2006. Am Ufer lauert der Tod – Jagdplätze des Neandertalers in der niederrheinischen Bucht: Ergebnisse einer archäologischen Prospektion der Abbaukanten im rheinischen Braunkohlerevier, in: Uelsberg, G. (Ed.), Roots/Wurzeln der Menschheit, pp. 269-288.

Uthmeier, T., Kels, H., Schirmer, W., Böhner, U. 2011. Neanderthals in the Cold: Middle Paleolithic Sites from the Open-Cast Mine of Garzweiler, Nordrhein-Westfalen (Germany), in: Conard, N.J., Richter, J. (Eds.), Neanderthal Lifeways, Subsidence and Technology. One Hundred Fifty Years of Neanderthal Study. Vertebrate Paleobiology and Paleoanthrology 19: 25-41.

Vandenberghe, D., Derese, C., Houbrechts, G., 2007. Residual Doses in Recent Alluvial Sediments From the Ardenne (S Belgium). Geochronometria 28, 1–8. doi:10.2478/v10003- 007-0024-z

178 | REFERENCES

Vandenberghe, J., Huijzer, B.S., Mücher, H., Laan, W., 1998. Short climatic oscillations in a western European loess sequence (Kesselt, Belgium). J. Quaternary Sci. 13, 471–485. doi:10.1002/(SICI)1099-1417(1998090)13:5<471::AID-JQS401>3.0.CO;2-T

Vandenberghe, J., Nugteren, G., 2001. Rapid climatic changes recorded in loess successions. Global and Planetary Change, Recognition of abrupt climate changers in clastic environments 28, 1–9. doi:10.1016/S0921-8181(00)00060-6

Vandenberghe, J., Renssen, H., Roche, D.M., Goosse, H., Velichko, A.A., Gorbunov, A., Levavasseur, G., 2012. Eurasian permafrost instability constrained by reduced sea-ice cover. Quaternary Science Reviews 34, 16–23. doi:10.1016/j.quascirev.2011.12.001.

Van Baelen, A., Meijs, E.P.M., Van Peer, P., de Warrimont, J.-P., de Bie, M., 2007. An early Middle Palaeolithic site at Kesselt-Op de Schans (Belgian Limburg): preliminary results. Notae Praehistoricae 27, 19-26.

Van Baelen, A., Vroomans, J.-M., Van Peer, P., 2011. A diachronic perspective on the Palaeolithic occupations at Kesselt-Op de Schans. In: Toussaint, M., Di Modica, K., Pirson, S. (Eds.). Le Paléolithique moyen en Belgique, Mélanges Marguerite Ulrix-Closset, 395–398.

Van den Haute, P., Vancraeynest, L., De Corte, F., 1998. The Late Pleistocene loess deposits and palaeosols of eastern Belgium: new TL age determinations. Journal of Quaternary Science 13, 487–497. doi:10.1002/(SICI)1099-1417(1998090)13:5<487::AID- JQS405>3.0.CO;2-Z

Van den Haute, P., Frechen, M., Buylaert, J.-P., Vandenberghe, D., De Corte, F., 2003. The Last Interglacial palaeosol in the Belgian loess belt: TL age record. Quaternary Science Reviews, LED 2002 22, 985–990. doi:10.1016/S0277-3791(03)00023-4.

Vandergoes, M.J., Hogg, A.G., Lowe, D.J., Newnham, R.M., Denton, G.H., Southon, J., Barrell, D.J.A., Wilson, C.J.N., McGlone, M.S., Allan, A.S.R., Almond, P.C., Petchey, F., Dabell, K., Dieffenbacher-Krall, A.C., Blaauw, M., 2013. A revised age for the Kawakawa/Oruanui tephra, a key marker for the Last Glacial Maximum in New Zealand. Quaternary Science Reviews, Linking Southern Hemisphere records and past circulation patterns: the AUS- INTIMATE project 74, 195–201. doi:10.1016/j.quascirev.2012.11.006

Van Huissteden, J., Kasse, C., 2001. Detection of rapid climate change in Last Glacial fluvial successions in The Netherlands. Global and Planetary Change, Recognition of abrupt climate changes in clastic environments 28, 319–339. doi:10.1016/S0921-8181(00)00082-5

Van Loon, A.J., 2006. Lost loesses. Earth-Science Reviews 74, 309-316.

Van Vliet-Lanoë, B., 1989. Dynamics and extent of the Weichselian permafrost in western Europe (Substage 5E to stage 1). Quaternary International 3–4, 109–113. doi:10.1016/1040- 6182(89)90080-3 REFERENCES | 179

Van Vliet-Lanoë, B., 1998. Frost and soils: implications for paleosols, paleoclimates and stratigraphy. CATENA 34, 157–183. doi:10.1016/S0341-8162(98)00087-3

Vinther, B.M., Clausen, H.B., Johnsen, S.J., Rasmussen, S.O., Andersen, K.K., Buchardt, S.L., Dahl-Jensen, D., Seierstad, I.K., Siggaard-Andersen, M.-L., Steffensen, J.P., Svensson, A., Olsen, J., Heinemeier, J., 2006. A synchronized dating of three Greenland ice cores throughout the Holocene. J. Geophys. Res. 111, D13102. doi:10.1029/2005JD006921

Vreeken, W., 1984. (re) Deposition of Loess in Southern Limbourg, the Netherlands .3. Field Evidence for Conditions of Deposition of the Middle and Upper Silt Loam Complexes, and Landscape Evolution at Nagelbeek. Earth Surf. Process. Landf. 9, 1–18. doi:10.1002/esp.3290090102

Wallinga, J., Murray, A., Wintle, A., 2000. The single-aliquot regenerative-dose (SAR) protocol applied to coarse-grain feldspar. Radiation Measurements 32, 529–533. doi:10.1016/S1350- 4487(00)00091-3

Wagenbreth, O., 2015. Die Geschichte der Geologie in Deutschland. Springer, Berlin, Heidelberg. doi:10.1007/978-3-662-44712-3.

Walter, R., 2007. Geologie von Mitteleuropa. Schweizerbart’sche Verlagsbuchhaltung, Stuttgart.

Washburn, A.L., 1979. Geocryology. Edward Arnold, London.

Weidenfeller, M., Löhr, H., Zöller, L., 1994. Das Lößprofil Issel und seine Bedeutung für die Stratigraphie des jüngeren Quartärs der Mittelmosel. Mainzer Geowiss. Mitt., 23, 139-152.

Wintle, A.G., 1973. Anomalous Fading of Thermo-luminescence in Mineral Samples. Nature 245, 143–144. doi:10.1038/245143a0

Wintle, A. G. 1981: Thermoluminescence dating of Late Devensian loesses in southern England. Nature 289, 479–480.

Wintle, A. G., 1987. Thermoluminescence dating of loess at Rocourt, Belgium. Geologie en Mijnbouw, 66, 35-42.

Wintle, A.G., Brunnacker, K., 1982. Ages of volcanic tuff in Rheinhessen obtained by thermoluminescence dating of loess. Naturwissenschaften 69, 181-183.

Wintle, A.G., Murray, A.S., 2006. A review of quartz optically stimulated luminescence characteristics and their relevance in single-aliquot regeneration dating protocols. Radiation Measurements 41, 369–391. doi:10.1016/j.radmeas.2005.11.001

Wolff, E.W., Chappellaz, J., Blunier, T., Rasmussen, S.O., Svensson, A., 2010. Millennial-scale variability during the last glacial: The ice core record. Quaternary Science Reviews,

180 | REFERENCES

Vegetation Response to Millennial-scale Variability during the Last Glacial 29, 2828–2838. doi:10.1016/j.quascirev.2009.10.013

Wolpert, T. 2015. Chronostratigraphische Einordnung spezifischer Marker-Horizonte des Lössprofils Nussloch / Heidelberg mit der OSL-Datierungsmethode. BSc Thesis. JLU Gießen.

Zagwijn W.H., van Staalduinen C.J. (eds.), 1975. Toelichtingen bij the geologische overzichtskarten van Nederland. Rijks Geologische Dienst, Haarlem.

Zagwijn, W.H., Paepe, R., 1968. Die Stratigraphie der weichselzeitlichen Ablagerungen der Niederlande und Belgiens. Eiszeitalter und Gegenwart 19, 129-146.

Zech, M., Rass, S., Buggle, B., Löscher, M., Zöller, L., 2012. Reconstruction of the late Quaternary paleoenvironments of the Nussloch loess paleosol sequence, Germany, using n-alkane biomarkers. Quaternary Research 78, 226–235. doi:10.1016/j.yqres.2012.05.006.

Zech, M., Krause, T., Meszner, S., Faust, D., 2013. Incorrect when uncorrected: Reconstructing vegetation history using n-alkane biomarkers in loess-paleosol sequences – A case study from the Saxonian loess region, Germany. Quaternary International 296, 108-116. doi: 10.1016/j.quaint.2012.01.023.

Zens, J., Zeeden, C., Römer, W., Fuchs, M., Klasen, N., Lehmkuhl, F., 2017. The Eltville Tephra (Western Europe) age revised: Integrating stratigraphic and dating information from different Last Glacial loess localities. Palaeogeography, Palaeoclimatology, Palaeoecology 466, 240–251. doi:10.1016/j.palaeo.2016.11.033

Zimmermann, D.W., 1971. Thermoluminescence dating using fine grains from pottery. Archaeometry 13, 29-52.

Zöller, L., 1989. Geomorphologische und geologische Interpretation von Thermolumineszenz- Daten. Bayreuther Geowissenschaftliche Arbeiten, 14, 103-112.

Zöller, L., 1995. Würm-und Rißlößstratigraphie und Thermolumineszenz-Datierung in Süddeutschland und angrenzenden Gebieten.-Habil.schrift Fak. f. Geowissenschaften, Univ. Heidelberg (unpublished).

Zöller, L., Stremme, H.E., Wagner, G.A., 1988. Thermolumineszenz-Datierung an Löß- Paläoboden-Sequenzen von Nieder-, Mittel- und Oberrhein. Chemical Geology (Isot. Geosc. Sect.) 73, 39-62.

Zöller, L., Wagner, G.A., 1989. Thermoluminescence dating applied to paleosols. Quaternary International 1, 61–64. doi:10.1016/1040-6182(89)90009-8

Zöller, L., Wagner, G.A., 1990. Thermoluminescence dating of loess—Recent developments. Quaternary International 7–8, 119–128. doi:10.1016/1040-6182(90)90046-7 REFERENCES | 181

Zöller, L., Semmel, A., 2001. 175 years of loess research in Germany – long records and “unconformities“. Earth-Sciences Reviews 54, 19-28.

Zöller, L., Richter, D., Masuth, S., Wunner, L., Fischer, M., Antl-Weiser, W., 2013. Luminescence chronology of the Grub-Kranawetberg site, Austria. EG Quat. Sci. J. 62, 127– 135. doi:0.3285/eg.62.2.04

182 | APPENDIX

Appendix

Supplementary material Chapter 4 S4-1: Supplement with all sections including concept for loess deposition and preservation in relation to geomorphological setting

We defined four different geomorphological positions for the position of loess sections (S4-1_Tab. 1). The development of fossil soils and /or soil sediments is influenced by sedimentation, erosion, and re-deposition. Calcification, decalcification, slope wash, solution and soil processes play crucial roles. For example, plateau situations do not have any slope wash but deflation. Very often lower accumulation rates and erosion discordances can occur. In addition, frost and desiccation cracks can be found (see Lehmkuhl 2016). Sections on plateaus are often incomplete due to deflation. Generally the strongest erosion occurs on slope positions. In periglacial environments slope wash in combination with nivation (snow accumulation and ablation) and gelifluctions appeared (French, 2007). In such environments erosion starts already with a 2° slope gradient (cf. Washburn, 1979; French, 2007). Most LPS are located on slope toe positions and less erosion but stronger accumulation happens. The slope aspect also reveals that loess was mainly deposited on eastern (lee) sites. Very often asymmetric (periglacial) valleys strengthened this process. Especially in depressions but also at slope toes different soil processes occurred since the accumulation.

S4-1_Tab. 1: Processes in loess in relation to the relief (A: Plateau, B: Slope, C: Slope toe, and D: Depression). The impact of different processes according to the position of loess sections from weak (-), to medium (+-), strong (+) and very stong (++).

A: Plateau B: Slope C: Slope toe D: Depressions and Erosional channels 1: Slope wash and hill slope - ++ + - processes 2: Slope aspect (W-E - ++ + - / N-S) 3: Accumulation +- - + ++ 4: Cryogenic features + - - - - ++ + a) frost cracks

b) Ablation and solifluction 5: Decalcification +- + + +- and solution 6: intensity soil +- - + ++ development

APPENDIX | 183

LPS from the Lower Rhine Embayment and adjacent areas

S4-1_Fig. 1: Wegberg (Paas, 1962) (for details see S4-2_Tab. 1).

Parabraunerde = Luvisol, Jüngerer Weichel-Löß = younger Weichselian loess, Braunerde = Cambisol, Bodenbildung = pedogenesis, Älterer Weichsel-Löß = older Weichselian loess, Pseudogley = Pseudogley, braunlehmartiger gelblichroter Boden = brown loamy yellow-reddish soil, Hauptterasse = main terrace.

S4-1_Fig. 2: Rheindahlen (Schirmer, 2002a; Schirmer and Feldmann, 1992) (for details see S4- 2_Tab. 1).

184 | APPENDIX

S4-1_Fig. 3a: Erkelenz (Paas, 1992) (for details see S4-2_Tab. 1).

Weichsel-Kaltzeit = Weichselian Glacial, Saale-Kaltzeit = Saalian Glacial, Elster-Kaltzeit = Elsterien Glacial, Altpleistozän = Lower Pleistocene, Humuszone = humus zone, Erosionsdirkordanz = erosion discordance, Korngrößenverteilung = grain size distribution, Grobsand = coarse sand, Fein- und Mittelsand = fine and medium sand, Großschluff = coarse silt, Mittelschluff = medium silt, Feinschluff = fine silt, Ton = clay, T-Wert = clay value. APPENDIX | 185

S4-1_Fig. 3b: Erkelenz (Schirmer, 2002b) (for details see S4-2_Tab. 1).

S4-1_Fig. 4: Holzweiler (Kels, 2007) (for details see S4-2_Tab. 1).

186 | APPENDIX

S4-1_Fig. 5a: Garweiler I (Kels, 2007) (for details see S4-2_Tab. 1).

S4-1_Fig. 5b: Elsbachtal (Kels, 2007) (for details see S4-2_Tab. 1).

Holozänes Kolluvium = Holocene colluvium (anthoposol), Kesselt-Lage = Kesselt layer, Eben-Zone = Eben zone, Eben-Diskordanz = Eben discordance, Rocourt Solkomplex = Rocourt soils, Hauptterrassenschotter = gravel of the main terrace, eemzeitliche Parabraunerde (Rocourt-Boden) = Eemian Luvisol (Rocourt soil), OSL-Beprobung = OSL samples, Mikromorphologie-Beprobung = samples for micromorphology analyses. APPENDIX | 187

S4-1_Fig. 6: Titz 1 (left) and 2 (right) (Kels, 2007) (for details see S4-2_Tab. 1).

188 | APPENDIX

S4-1_Fig. 7: Inden (Paas, 1968b) (for details see S4-2_Tab. 1).

Hauptterrasse = main terrace. APPENDIX | 189

S4-1_Fig. 8: Beggendorf (Remy, 1960, Schirmer, 2003) (for details see S4-2_Tab. 1).

S4-1_Fig. 9: Birkesdorf (Schalich, 1968) (for details see S4-2_Tab. 1).

Aufgelassener Ziegelei-Aufschluß Gerhards = section of the former brickyard Gerhards, Holozän = Holocene, Pleistozän = Pleistocene, Auenlehm = loamy sediments from floodplains, Abschlammassen = mud masses, Hangschutt = colluvium, Junger Wurmlöß = Upper Weichselian loess, Fließerde = solifluction soils, Niederterrasse = lower terrace, Hauptterrasse = main terrace.

190 | APPENDIX

S4-1_Fig. 10: Lommersum (Brunnacker et al., 1978) (for details see S4-2 Tab. _ 1).

1 = humoser Pflughoriziont = humus rich ploughed horizon, 2 = rotbraune Parabraunerde = Luvisol (red-brown), 3 = gelbsandiger Schluff = yellowish sandy silt, 4 = rostbraune Sand- bzw. Kiesbänder = auburn bands of gravel and sand, 5 = gelblicher Löß = yellowish loess, 6 = rötlicher Sand = reddish sand, 7 = brauner Lehm = brownish loam, 8 = lehmiger Sand = loamy sand, 9 = dunkler graubraungelber Löß = dark grey-brown-yellowish loess, 10 = heller graubraungelber Löß = light grey-brown-yellowish loess, 11 = Manganband = band of mangenese, 12 = Diskordanz = discordance. APPENDIX | 191

S4-1_Fig. 11: Weilerswist (Henze, 1998) (for details see S4-2_Tab. 1).

Profil = section, jHT = jüngere Hauptterrasse = younger main terrace.

S4-1_Fig. 12: Garzen near Brühl (Henze, 1998) (for details see S4-2_Tab. 1).

Profile = sections, Bauschutt = rubble.

192 | APPENDIX

S4-1_Fig. 13: Kreuzweingarten (Janus, 1998) (for details see S4-2_Tab. 1).

Profil = section, Mersbachtal = Mersbach valley, Schwemmlöß = alluvial / reworked loess, Jungwürmlöß = Upper Weichselian loess, Mittelwürmlöß = Middle Weichselian loess, Eem-Boden = Eemian soil, Bodensediment = soil sediment, Schuttschnüre = bands of debris, Humuszone = humus zone, Aufschüttung = accumulation (deposit), Wandschutt = accumulation (deposit).

S4-1_Fig. 14: Bonn- Lengsdorf (Bartels/Hard, 1974) (for details see S4-2_Tab. 1).

1 = Schotter der jüngeren Hauptterrasse = gravel of the younger main terrace, 1‘ = eingeschalteter selbergitisch- basaltischer Mischtuff = mixed tuff, 2 = Löß, nahe der alten Oberfläche stark verwittert (2‘) = loess (weathered 2‘), 3 = Rodderberg-Tuff = Rodderberg tuff, 3‘ = stark verwitterter Rodderberg-Tuff = strongly weathered Rodderberg tuff, 4 = verwitterter Löß = weathered loess, 5 = Schwemmsand = alluvial sand, 6 = lehmsandige Fließerden = loamy and sandy solifluction soils, 7 = Schwemm- und Fließlöß = alluvial loess, 8 = Bt-Material, teilweise autochthon = material from the Bt-horizon, partial autochthonous, 9 = lehmiges rostbraunes Bodensediment mit verlagerten Fahnen von Rodderberg-Tuff = loamy red-brownish soil sediment with bands of reworked Rodderberg tuff, 10 = sandiger Lößlehm = sandy loessic loam, 11 = Humuszone = humus zone, 12 = Fließlöß mit Fließerdebändern und Geröllen = alluvial loess with bands of solifluction soil material and gravel, 13 = untere Verbraunungszone = lower browning zone, 14 = gelblicher Schwemm- und Fließlöß = yellowish alluvial loess, 15 = obere Verbraunungszone = upper browning zone, 16 = gelblich-grauer Löß = yellow-greyish loess. APPENDIX | 193

S4-1_Fig. 15: Schwalbenberg (Frechen and Schirmer, 2011) (for details see S4-2_Tab. 1).

194 | APPENDIX

S4-1_Fig. 16: Vinkenpützer Grund (Fischer, 2010) (for details see S4-2_Tab. 1).

Höhe (m) ü. NN = elevation (m) a.s.l., Störungsbereich durch Rheinische Trinkwasserleitung = disturbance due to the Rhenish drinking water pipe line, Profillänge = lenght of the section. APPENDIX | 195

S4-1_Fig. 17: Hochdahl-Neandertal (Schündeln and Radtke, 1998) (for details see S4-2_Tab. 1).

Source: Schündeln, M., Radtke, U., 1998. Lumineszenzdatierung des Lößprofils „Hochdahl- Neandertal" unter besonderer Berücksichtigung methodischer Aspekte. – In: Radtke, U. [Hrsg.]: Lumineszenzdatierung äolischer Sedimente. - Kölner Geographische Arbeiten, 70, 65- 77.

196 | APPENDIX

S4-1_Fig. 18: Grafenberg (Henze, 1998) (for details see S4-2_Tab. 1).

Lage der Lumineszenz Proben = position of the OSL samples.

APPENDIX | 197

LPS from the foreland of the Harz Mountains

S4-1_Fig. 19: Salzgitter-Drütte (Feldmann, 2002) (for details see S4-3_Tab. 1).

1 = Ap-Horizont = Ap horizon (plough horizon), 2 = Bt-Horizont = Bt horizon (luvisol), 3 = Bv-Horizont = Bv horizon (Cambisol), 4 = Go-Horizont = Go horizon (gley), 5 = Gr-Horizont = Gr horizon (gley), 6 = Sand = sand, 7 = Kies = gravel, Lol = Lößlehm = loamy loess, Loss = Sandstreifenlöß = loess with sandy bands, gf = Glazifluviatil = glacial fluviatile, Lg = Geschiebelehm = boulder clay, periglazial = periglacial, ky = kryoturbat = cryoturbat.

198 | APPENDIX

S4-1_Fig. 20: Bornhausen (Feldmann, 2002) (for details see S4-3_Tab. 1).

Sand = sand, Kies = gravel, Al-Horizont = Al horizon (plough horizon), 2 = Bt-Horizont = Bt horizon (luvisol), 3 = Bv-Horizont = Bv horizon (cambisol), Eisenanreicherung (Go) = iron concretions (gley), Bleichung = bleaching, Manganoxid-Konkretionen = manganese concretions. APPENDIX | 199

S4-1_Fig. 21: Beuchte (Feldmann, 2002) (for details see S4-3_Tab. 1).

Braungrau = brown-greyish material; gelbbraun = yellow-brownish material; braunrot, Pseudogley-Fahnen = brown-reddish material withbands of pseudogley; rötlichbraun, Fe-Konkretionen = red-brownish material with iron concretions; braun = brownish material; gelbbraun, CaCO3-Konkretionen = yellow-brownish material with

CaCO3 concretions; gelbbraun, Mn-Konkretionen = yellow-brownish material with manganese concretions; gelbbraun, hellgelb-marmoriert, Mn-Konkretionen, braune Schluffgerölle = yellow-brownish material, partly yellow marbled, with manganese concretions and brown silty debris; braungelb = brown-yellowish material; hellbraungrau-marmoriert, weiße Flecken = brown-grey marbled material with white spots; hellbraungrau, Rostschlieren = light brown-greyish amterial with rust smears; braun, lagenweise grau-marmoriert, Rosthöfe, lagenweise rostfarbig, CaCO3-Konkretionen = brownish material with some grey marbled layers, rust, some layers rust-colored and CaCO3 concretions; gelbbraun = yellow-brownis material.

200 | APPENDIX

S4-1_Fig. 22: Wülperode (Feldmann, 2002) (for details see S4-3_Tab. 1).

Braungrau = brown-greyish material; rötlichbraun, Wühlgänge = red-brownish material, bioturbation; rötlichbraun = red-brownish material; gelbbraun, durchwühlt = yellow-brownish, bioturbated material; an Basis

Schotterlage, c5, bräunlichgelb, CaCO3-Konkretionen = at the base a gravel layer, c5, brown-yellowish material with CaCO3 concretions; an Basis m-gG-Lage, c5, gelb, Rostflecken= at the base a m-gG-layer, c5, yellowish material with rusty spots; dunkelgelb, c5, vereinzelt Rostflecken = dark yellowish material, c5, with some rusty spots; CaCO3-Konkretionen = CaCO3 concretions; graugelb/rostfarben marmoriert, dunkelbraune Bändchen, Mn-Konkretionen = grey-yellowish/rust-brownish marbled, with dark brownish bands and manganese concretions; bräunlichgelb, vereinzelt Rostbänder, c5, vereinzelt CaCO3-Konkr., Mn-Konkr. = brown-yellowish material withsome rust bands , c5, with some CaCO3 concretions and some manganese concretions; graugelb, Rostbänder, lagenweise braune Bänder und Schluffgerölle, c4, Mn-Konkretionen = grey-yellowish material with rusty bands, brown bands and silt debris, c4, manganese concretions; braungelb, c5, Lößkindl, an Basis braune Schluffgerölle = brown-yellowish material, c5, with loess dolls, and brown silty debris at the base. APPENDIX | 201

S4-1_Fig. 22: Ermsleben (Reinecke, 2006) (for details see S4-3_Tab. 1).

OSL-Alter = OSL age.

202 | APPENDIX

S4-1_Fig. 23: Hecklingen (Reinecke, 2006) (for details see S4-3_Tab. 1).

S4-1_Fig. 24: Schadeleben (Reinecke, 2006) (for details see S4-3_Tab. 1).

OSL-Alter = OSL age.

APPENDIX | 203

S4-1_Fig. 25: Thale (Reinecke, 2006) (for details see S4-3_Tab. 1).

Fotoausschnitt = picture clip.

S4-1_Fig. 26: Lüttgenrode (Reinecke, 2006) (for details see S4-3_Tab. 1). OSL-Alter = OSL age.

204 | APPENDIX

S4-1_Fig. 27: Derenburg (Reinecke, 2006) (for details see S4-3_Tab. 1).

OSL-Alter = OSL age.

S4-1_Fig. 28: Beuchte (Reinecke, 2006) (for details see S4-3_Tab. 1).

OSL-Alter = OSL age.

APPENDIX | 205

S4-1_Fig. 29: Zilly (Reinecke, 2006) (for details see S4-3_Tab. 1).

S4-1_Fig. 30: Langenbogen (Kunert and Altermann, 1965) (for details see S4-3_Tab. 1).

1 = accumulation of humus, 2 = primary loess, 3 = alluvial loess, 4 = mud, 5 = loamy zone, 6 = cryosol, 7 = Buntsandstein.

206 | APPENDIX

S4-2_Tab. 1: Additional Information concerning important LPS in the Lower Rhine Embayment presented in Fig. 22.

section longitude/ references location in elevation thickness time relief position (A, B, C, D) and key message further references latitude Germany [m a.s.l.] span A = plateau, B = slope, C = slope toe, D = depression LOWER RHINELAND 1 - Wegberg Wegberg Ziegelei Simons ca. Paas 1962 Lower 76 ca. 11 m >OIS5 D - Important due to the accordance of a very old Brunnacker 1967 51.129260 N, Rhineland soil directly above the youngests major terrace. 6.283355 E The layers decline to the NE into a small valley 2 - Rheindahlen brickyard pit Dreesen 51.140361 N, Schirmer 2002 a, Schirmer/ Lower 75 ca. 9 m >OIS5 A - Weichselian loesses are completely missing, Brunnacker 1966, near Rheindahlen, 6.365028 E Feldmann 1992 Rhineland one of the best outcrops showing the Erft Kels 2007, between Rheindahlen and solcomplex in detail. Known for archaeological Mennrath excavations and records 3 - Erkelenz brickyard pit Gillrath near 51.075798 N, Paas 1992, Kels 2007, Lower 95 ca. 20 m OIS2, D - The brickyard pit Gillrath in Erkelenz Schirmer/Streit 1990 Erkelenz 6.333885 E Schirmer 2002 b Rhineland OIS5-11 exhibits the most complete loess stack of the bzw. 1967 Niederrhein. Formations of depressions where older, Pre-Eemian loesses could be conserved. 4 -Holzweiler Kiesgrube Schmitz; ca. Kels 2007 Lower 94 ca. 5 m >OIS5 A - known as a section with a alternating gravel Schnütgen 1990 Holzweiler section 1-5 51.046868, Rhineland beds; Holzweiler formation a a result of Maas 6.385865 discharge in northeastern direction in the LRE. 5 - Garzweiler I open pit mine Garzweiler, 51.051740 N, Kels 2007 Lower 96 ca. 14 m OIS2- C - Really long and completed sections, here 120 / 2 km northeast from 6.478109 E Rhineland >6 m length of this section.; Eben Discordance really Jackerath striking, Keldach Formation (OIS4) conserved, Brabant loess (OIS2) conserved 5 - Elsbachtal open pit mine 51.082941 N, Kels 2007 Lower 83 ca. 20 m OIS1-6 D - This section is an example for depressions Fischer et al. 2012, Garzweiler/Elsbachtal 6.501649 E Rhineland which can be filled by anthropogenic activities. Protze 2014 6 - Titz Titz 1-2 ca. 50.998165 N, Kels 2007 Lower 95 4 bzw. 12 m >OIS5 ? - The basel terrace is gleyish. Half of the section / 6.437926 E Rhineland build up uf Brabantian loess with the compelte stratigraphy. 7 - north of the channel from the north of 50.881280 N, Paas 1968b Lower unspecified ca. 11 m >OIS5 / Kels 2007 open cast mine the open cast mine Inden 6.327094 E Rhineland Inden 8 - Beggendorf Beggendorf brickworks Remy 1960, Schirmer 2003 Lower unspecified 10 m >OIS5 ? - Soil formations of the Middle Pleniglacial are / Rosen in the SE of 50.923367 N, Rhineland presved as 'Nassböden'. Eben-Zone typically Geilenkirchen 6.180392 E developed 9 - Birkesdorf margin of the valley of 50.818747 N, Schalich 1968 Lower unspecified ca. 6 m OIS2 B - strong periglacial influence due to Kels 2007 the river Rur near 6.477399 E Rhineland solifluction, only 5 m loess preseved, mostly UPG Birkesdorf loess and reworked loess below 10 - Lommersum western slope of a small 50.706476 N, Brunnacker et al. 1978 Lower unspecified ca. 5 m OIS3 C - known for archaeological excavations and Kels 2007 valley with less channel 6.786175 E Rhineland records; conservation and accumulation of loess flow on a slope toe 11 - Weilerswist gravel pit near 50.767170 N, Henze 1998 Lower unspecified ca. 8 m >OIS5 B - Loess section controlled by Luv -Lee effects. Kels 2007 Weilerswist; on top of a 6.860476 E Rhineland Luv only thin loess cover, Luv up to 7.5 m. No skid of the SE Zulpicher clear soil layer making a stratigraphical position Börde on the western possible.Henze suggested that the sections is slope of the Ville only build up by Weichselian deposits. APPENDIX | 207

12- brickworks at the westwall of the 50.822235 N, Henze 1998 Lower unspecified ca. 7 m >OIS5 B - Strong relocation processes during the Mückenhausen 1954 Garzen near Brühl former brickyard Garzen 6.889872 E Rhineland second phase of the OIS 2 leading to a reduced (Brühl) at the eastern thickness of these sediments. Sandy loess and slope of the Ville pebbles are intercalated in the reworked sediments 13- Kreuzweingarten near section in a Janus 1988 Lower unspecified ca. 5m OIS2- 5 A - Every phase of the Last Glacial Cycle is partly Kels 2007 Kreuzweingarten Euskirchen, wall section building pit, today Rhineland e-a preseved. Possibly one of the few known sections SE-NW, on top of a skid no longer existent with occurence of the Erbenheim Soils in the between Erft and and reproducable Lower Rhine Embayment Mersbach 14 - Bonn- Bonn-Lengsdorf on the 50.702430 N, Bartels/Hard 1974 Lower unspecified ca. 8 m >OIS5 / / Lengsdorf highway near the 7.064464 E Rhineland Hardtberg 15 - Remagen - Schwalbenberg II 50.561070 N, Frechen/Schirmer 2011 Lower 92 13,5 m OIS2-5 A - C - The loess/palaeosol sequence of the Schirmer 1990, 1991, Schwalbenberg 7.244691 E Rhineland Schwalbenberg II loess section shows a 2000b, 2012, Klasen remarkable detailed Weichselian Middle et al. 2015 Pleniglacial (MIS 3) record. A detailed and more reliable chronological framework was set up by luminescence dating methods for the loess record resulting in four major accumulation periods for this last glacial record. The chronological results give further evidence for the litho-pedological correlation of the Hesbaye Formation and the Ahrgau Formation to MIS 2 and MIS 3, respectively. The Keldach Formation is designated to correlate to MIS 4 by means of litho-pedostratigraphy but gives deposition ages between 55 and 45 ka, which does suggest a correlation to MIS 3. 16 - Vinkenpützer section 1, beginning of the 51.024061 N, Fischer 2010 Lower ca. 70 - 80 till max. 22 m >OIS5 A - D - Valley head of the Vinkenpützer Grund; Fischer 2003 Grund valley of the 6.729034 E (1/1) Rhineland several digging hole along a cross section from Vinkenpützer Grund (dry till 51.025587 N, NW to SE exposed slopes, loess mainly pre valleys), 750 m long 6.722217 E (1/10) eemian 17 - Hochdahl- Kalksteinbruch im 51.227236 N, Schündeln/Radtke 1998 Lower 125 ca. 13,5 m OIS4 B - C- Predominantly reworked loess above Gerlach 1992 Neandertal Neadertal 6.942040 E Rhineland above devonian limestone; major loess accumulation during LGM and Late Glacial 18 - Düsseldorf W exposed slope in a 51.256527 N, Henze 1998 Lower unspecified 16 m >OIS5 B - C - Loess of the Last Glacial Cycle, very often Remy 1960 Grafenberg claypit nearby Grafenberg 6.834191 E Rhineland relocated; different units preseved at different position along the slope

208 | APPENDIX

S4-3_Tab. 1: Additional Information concerning important LPS in the northern foreland of the Harz Mountains presented in Fig. 24Fig. 22.

section longitude/ references location in elevation thickness time relief position (A, B, C, D) and key message further references latitude Germany [m a.s.l.] span A = plateau, B = slope, C = slope toe, D = depression NORTHERN FORELAND OF THE HARZ MOUNTAINS 1- section in the north 52.162225 N, Feldmann 2002 Northern 90 3m ≥ OIS6? Loess cover and the Eemian soil are only preserved as / Salzgitter- of the gravel pit 10.461714E foreland of fragments in sink holes. Drütte Salzgitter-Drütte the Harz Mountains 2- section in the gravel 51.923725 N, Feldmann 2002 Northern 165 6m OIS5e? Below the recent soil several interstadial soils made up / Bornhausen pit on the Nordberg 10.152025 E foreland of of different material follow. the bottom builds the near Bornhausen the Harz Eemian soil. Mountains 3- Beuchte Obere Schierksmühle, 51.990057 N, Feldmann 2002 Northern 129 6m OIS2-3 B - Young Pleistocene sequence Reinecke 2006 western slope of the 10.504078 E foreland of Weddebach valley the Harz near Beuchte, former Mountains loess quarry 4- Wülperode western slope of the 51.984656 N, Feldmann 2002 Northern 131 4,5m OIS2-3 B -Young Pleistocene sequence with several loess / Stimmecke valley 10.613580 E foreland of units and tundra gleys alternating. near Wülperode the Harz Mountains 5 - Ermsleben "Hohlweg 51.720547 N, Reinecke 2006 Northern 180 9,5 m OIS2-4 Middle Weichselian loess units which can be / Konradsburg", 1 km 11.343883 E foreland of discovered in the eastern part of the northern foreland south of the Harz of the Harz Mountains. Ermsleben is an exceptional Falkenstein/Harz, 1,5 Mountains geomorphological case for continuing accumulation in km south-east of the Middle Weichselian. Ermsleben 6 - Hecklingen 1 km south of 51.839249 N, Reinecke 2006 Northern 107 7 m OIS2-4 B - Middle Weichselian loess units which can be / Hecklingen, 11.522854 E foreland of discovered in the eastern part of the northern foreland Hecklingen the Harz of the Harz Mountains. Hecklinger Soil „Lehmgrube westl. Mountains Ortsrand“ 7 - Schade- Schadeleben 51.837065 N, Reinecke 2006 Northern 128 7 m OIS2-3 Schadeleben exhibits the most complete sequence of / leben „Hasselgrund“, 1,5 11.383598 E foreland of the Late Weichselian loess and soil units in the study km east of the Harz area of the northern foreland of the Harz Mountains. Schadeleben Mountains 8- Thale Thale, 51.763215 N, Reinecke 2006 Northern 180 2,5 m OIS2 B - Thale is an example of the formation of a / "Preußenstein"; 11.028712 E foreland of depression in upper Weichselian loess. The depression construction pit at the Harz reaches down to the gravel of the Middle terrace. the western edge of Mountains the town Thale 9- Lüttgenrode Lüttgenrode, 51.969566 N, Reinecke 2006 Northern 145 4 m OIS2 B - Older bleached loesses accumulated in the slope / "Westtor" 10.653190 E foreland of situation of Lüttgenrode. Traces of cryoturbation are visible. APPENDIX | 209

the Harz Mountains 10- Derenburg Derenburg, "pit Luvos 51.882546 N, Reinecke 2006 Northern 173 4 m OIS2 B - Only one but strongly developed tundra gley is / Heilerde" 10.902694 E foreland of preseved here. It is covered by a 1.5 m thick layer of the Harz pure loess. Mountains 11- Beuchte Beuchte, "Obere 51.990605 N, Reinecke 2006 Northern 130 5,5 m OIS2 see 3. Feldmann 2002 Schierksmühle" 10.504787 E foreland of the Harz Mountains 12- Zilly Zilly, "Galgenberg" 51.937687 N, Reinecke 2006 Northern 170 4,5 m OIS2 B - Represents the youngest loess cover. Pure loess / 10.841730 E foreland of with no signs of pedogenic processes taken place the Harz during and after accumulation accept the recent soil. Mountains 13- Langen- Langenbogen 51.490092 N, Reinecke 2006 Northern 123 6 m OIS2-5 Naturally formed canyons made of loess with up to 20 Kunert/Altermann bogen "Hammerlöcher" 11.775015 E foreland of m high walls covering the last glacial and parts of the 1965 the Harz last interglacial. Mountains

210 | APPENDIX

Supplementary material Chapter 5 S5_Tab. 1: Collection of luminescence ages surrounding the Eltville Tephra.

Stratigraphic po- Signal / particle size Profile Sample Age [ka] 1-σ Protocol Mineral Fading tests Optical filter reference sition methode [um] Rocourt QTL 89B 13.5 1.2 > E4 TL MARD polymineral 4-11 n/a - Wintle 1987 Rocourt QTL 78B 15.3 1.3 E4 TL MARD polymineral 4-11 n/a UG 11 Juvigné and Wintle 1988 Rocourt QTL 103A 15.9 1.3 E4 - ET TL MARD polymineral 4-11 n/a UG 11 Juvigné and Wintle 1988 Lixhe QTL 77B 15.8 1.3 E4 TL MARD polymineral 4-11 n/a UG 11 Juvigné and Wintle 1988 Ringen QTL 55B 16.4 1.4 ET - E2 TL MARD polymineral 4-11 n/a UG 11 Juvigné and Wintle 1988 Mainz-Weisenau MW1 42.7 8.4 > ET TL MARD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW3 42.9 3.1 > ET TL MAAD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW1 49.6 5.6 > ET TL MAAD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Wallertheim QTL32a 19.0 1.9 E4 - ET TL MA? polymineral ? n/a n/s Wintle & Brunnacker 1982 Mainz-Weisenau MW 3 18.9 1.9 > ET green OSL MARD polymineral 4-11 - - - U-340 Frechen & Preusser 1996 Mainz-Weisenau MW11 20.6 1.9 > ET green OSL MARD polymineral 4-11 - - - U-340 Frechen & Preusser 1996 Mainz-Weisenau MW3 25.4 7.4 > ET TL MARD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW11 27.7 7.8 > ET TL MARD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW11 27.7 3.9 > ET TL MAAD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Ockenfels OCK9 26.1 3.2 E4 - ET TL MARD polymineral 4-11 n/a BG 39 Preusser & Frechen 1999 Ockenfels OCK7 26.3 4.6 E4 - ET TL MARD polymineral 4-11 n/a BG 39 Preusser & Frechen 1999 Ockenfels OCK9 21.1 4.8 E4 - ET TL MAAD polymineral 4-11 n/a BG 39 Preusser & Frechen 1999 Ockenfels OCK7 27.5 7.1 E4 - ET TL MAAD polymineral 4-11 n/a BG 39 Preusser & Frechen 1999 Corning 5-58 and IR re- Wallertheim W10 31.4 3.5 E4 - ET TL MARD + MAAD quartz 45-124 - - - Buschbeck et al. 1992 jection filter Corning 5-58 and IR re- Wallertheim W 14 27.5 3.0 E4 - ET TL MARD + MAAD quartz 45-124 - - - Buschbeck et al. 1992 jection filter Corning 5-58 and IR re- Gräselberg GR135 21.4 2.5 E4 - ET TL MARD + MAAD quartz 63-124 - - - Buschbeck et al. 1992 jection filter Hattenheim HA-4 21.1 2.2 > ET TL MARD quartz 125-200 - - - Corning 5-58 Zöller et al. 1988 Mainz-Weisenau MW 3 19.2 2.0 > ET TL MARD polymineral 4-11 n/a U-340 Frechen & Preusser 1996 Mainz-Weisenau MW11 18.5 2.5 > ET TL MARD polymineral 4-11 n/a U-340 Frechen & Preusser 1996 Issel 1 TL1 16.5 2.0 > ET TL MARD polymineral 4-11 n/a Corning 5-58 Weidenfeller et al.1994 Storage test, 1 week by 75 °C, < Gräselberg Grä-1 20.6 1.7 E4 - ET TL MARD polymineral 4-11 Corning 5-58 Zöller 1989 10 % Mainz-Weisenau MW11 19.4 2.5 > ET IRSL50 MARD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW3 19.5 1.7 > ET IRSL50 MARD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW1 23.9 3.1 > ET IRSL50 MARD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW11 18.5 2.0 > ET IRSL50 MAAD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW3 17.8 2.6 > ET IRSL50 MAAD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW1 23.0 4.1 > ET IRSL50 MAAD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Ockenfels OCK7 20.5 3.5 E4 - ET IRSL50 MAAD polymineral 4-11 n/a BG 39 Preusser & Frechen 1999 Ockenfels OCK7 17.5 1.3 E4 - ET IRSL50 MARD polymineral 4-11 n/a BG 39 Preusser & Frechen 1999 Ockenfels OCK9 18.8 2.4 E4 - ET IRSL50 MAAD polymineral 4-11 n/a BG 39 Preusser & Frechen 1999 Ockenfels OCK9 17.2 1.7 E4 - ET IRSL50 MARD polymineral 4-11 n/a BG 39 Preusser & Frechen 1999 Nussloch HDS237 19.5 2.3 E4 - ET IRSL50 MAAD polymineral 4-11 Storage test, no fading BG39, 2 BG 3, GG400 Lang et al. 2003 Alsheim, Profil VII ALS-VII 5 18.5 1.5 > ET IRSL50 MAAD polymineral 4-11 n/a BG-39 / Corning 7-59 Techmer et al. 2006 Romont RMT2_6 26.8 2.1 E4 - ET pIRIR 290 SAR polymineral 4-11 no inteference filter (410 nm)

Romont RMT2_6 25.3 2.1 E4 - ET blue OSL SAR quartz 4-11 - - - U 340 Semrock HC414/46 nm + Ginseldorf GI26 23.3 3.0 > ET pIRIR 225 SAR polymineral 63-125 no Schmidt 2014 BG3 (3.5 mm) Ginseldorf GI26 27.6 4.2 > ET blue OSL SAR quartz 63-125 - - - Semrock HC377/50 + BG3 Schmidt 2014 Semrock HC414/46 nm + Münzenberg GI155 23.5 1.9 > ET+ET pIRIR225 SAR K-feldpsar 90-125 no unpublished Data by R. Steup BG3 (3.5 mm) Nussloch GI191 22.9 2.2 > ET green OSL SAR quartz 4-11 - - - Semrock HC377/50 + BG3 Wolpert 2015

Agesthe ET above Remagen-Schwalbenberg C-L2896 21.3 2.1 > ET blue OSL SAR quartz 40-63 - - - U 340 Klasen et al. 2015a Ringen RGE-4 24.3 1.8 ET pIRIR290 SAR polymineral 4-11 no inteference filter (410 nm) Ringen RGE-4 24.1 1.9 ET blue OSL SAR quartz 4-11 - - - U 340

Rocourt QTL 89H 17.1 1.4 ET - E2 TL MARD polymineral 4-11 n/a UG 11 Wintle 1987

Ages below the RocourtET QTL 103B 16.6 1.3 ET - E2 TL MARD polymineral 4-11 n/a UG 11 Juvigné and Wintle 1988 APPENDIX | 211

Rocourt QTL 78A 17.2 1.7 ET - E2 TL MARD polymineral 4-11 n/a UG 11 Juvigné and Wintle 1988 Ringen QTL 55A 16.1 1.4 ET - E2 TL MARD polymineral 4-11 n/a UG 11 Juvigné and Wintle 1988 Wallertheim QTL32b 19.0 1.9 ET - E2 TL MAAD polymineral ? n/a n/s Wintle & Brunnacker 1982 Mainz-Weisenau MW10 33.8 5.8 ET - E2 TL MARD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW2 34.2 10.5 ET - E2 TL MARD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Ockenfels OCK8 14.2 1.8 ET - E3 IRSL50 MARD polymineral 4-11 n/a BG-39 Preusser & Frechen 1999 Corning 5-58 and IR re- Wallertheim W13 33.0 3.9 ET - E2 TL MARD + MAAD quartz 45-124 - - - Buschbeck et al. 1992 jection filter Mainz-Weisenau MW 4 19.7 3.4 ET - E2 green OSL MARD polymineral 4-11 - - - U-340 Frechen & Preusser 1996 Mainz-Weisenau MW10 22.0 2.6 ET - E2 green OSL MARD polymineral 4-11 - - - U-340 Frechen & Preusser 1996 Mainz-Weisenau MW4 29.0 5.3 ET - E2 TL MARD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW10 29.4 4.7 ET - E2 TL MAAD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW4 28.2 4.7 ET - E2 TL MAAD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW2 31.8 6.7 ET - E2 TL MAAD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Ockenfels OCK8 19.5 5.0 ET - E3 TL MAAD polymineral 4-11 n/a BG-39 Preusser & Frechen 1999 Ockenfels OCK8 15.6 4.8 ET - E3 TL MARD polymineral 4-11 n/a BG-39 Preusser & Frechen 1999 Corning 5-58 and IR re- Gräselberg GR150 24.0 3.0 ET - E3 TL MARD + MAAD quartz 63-124 - - - Buschbeck et al. 1992 jection filter Corning 5-58 and IR re- Wallertheim W11 31.5 3.6 ET - E2 TL MARD + MAAD quartz 45-124 - - - Buschbeck et al. 1992 jection filter Corning 5-58 and IR re- Wallertheim W9 30.0 3.0 ET - E2 TL MARD + MAAD quartz 45-124 - - - Buschbeck et al. 1992 jection filter Mainz-Weisenau MW 4 20.5 3.5 ET - E2 TL MARD polymineral 4-11 n/a U-340 Frechen & Preusser 1996 Mainz-Weisenau MW10 22.1 2.0 ET - E2 TL MARD polymineral 4-11 n/a U-340 Frechen & Preusser 1996 Mainz-Weisenau MW10 18.9 1.5 ET - E2 IRSL50 MARD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW4 18.5 1.8 ET - E2 IRSL50 MARD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW2 21.0 2.5 ET - E2 IRSL50 MARD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW10 16.3 3.0 ET - E2 IRSL50 MAAD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW4 17.9 1.9 ET - E2 IRSL50 MAAD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Mainz-Weisenau MW2 19.4 1.9 ET - E2 IRSL50 MAAD polymineral 4-11 Storage test, no fading BG-39 Frechen 1999 Ockenfels OCK6 17.3 1.8 ET - E3 IRSL50 MAAD polymineral 4-11 n/a BG-39 Preusser & Frechen 1999 Ockenfels OCK6 18.0 1.9 ET - E3 IRSL50 MARD polymineral 4-11 n/a BG-39 Preusser & Frechen 1999 Ockenfels OCK8 16.5 2.2 ET - E3 IRSL50 MAAD polymineral 4-11 n/a BG-39 Preusser & Frechen 1999 Nussloch HDS238 19.2 1.7 ET - E3 IRSL50 MAAD polymineral 4-11 Storage test, no fading BG39, 2 BG 3, GG400 Lang et al. 2003 Alsheim ALS-VII 4 17.2 1.9 < ET IRSL50 MAAD polymineral 4-11 n/a BG-39 / Corning 7-59 Techmer et al. 2006 Romont RMT2_7 26.0 2.1 E4 - ET pIRIR 290 SAR polymineral 4-11 no inteference filter (410 nm) Romont RMT2_7 24.5 2.1 E4 - ET blue OSL SAR quartz 4-11 - - - U-340 Semrock HC414/46 nm + Ginseldorf GI27 20.0 2.5 < ET pIRIR 225 SAR polymineral 63-125 no Schmidt 2014 BG3 (3.5 mm) Ginseldorf GI27 25.9 3.9 < ET blue OSL SAR quartz 63-125 - - - Semrock HC377/50 + BG3 Schmidt 2014 Semrock HC414/46 nm + Münzenberg GI154 27.9 1.7 < ET pIRIR225 SAR K-feldpsar 90-125 no unpublished Data by R. Steup BG3 (3.5 mm) Nussloch GI190 20.5 2.0 < ET green OSL SAR quartz 4-11 - - - Semrock HC377/50 + BG3 Wolpert 2015 Nussloch NUP4-0809 23.1 1.9 ET - E3 blue OSL SAR quartz 32-40 - - - U 340 Tissoux et al. 2010 Nussloch BT1016 27.5 1.8 ET - E3 blue OSL SAR quartz 4-11 - - - U 340 Gocke et al. 2014 Remagen-Schwalbenberg C-L2897 23.0 2.3 ET - E3/E2 blue OSL SAR quartz 40-63 - - - U-340 Klasen et al. 2015a

212 | APPENDIX

S5_Tab. 2: Final dataset used for age modelling.

Age Stratigraphic Signal / particle Profile Sample [ka] 1-σ position methode Protocol Mineral size [um] Fading tests Optical filter reference Romont C-L4256 26.8 2.1 E4 - ET pIRIR 290 SAR polymineral 4-11 g = 0.47±0.28 % inteference filter (410 nm) this study

Romont C-L4156 25.3 2.1 E4 - ET blue OSL SAR quartz 4-11 - - - U 340 this study

Ginseldorf GI26 27.6 4.2 > ET blue OSL SAR quartz 63-125 - - - Semrock HC377/50 + BG3 Schmidt 2014

Tephra Nussloch GI191 22.9 2.2 > ET green OSL SAR quartz 4-11 - - - Semrock HC377/50 + BG3 Wolpert 2015

Ages the above Eltville Remagen-Schwalbenberg C-L2896 21.3 2.1 > ET blue OSL SAR quartz 40-63 - - - U 340 Klasen et al. 2015a

Ringen C-L3924 ET pIRIR290 SAR polymineral 4-11 inteference filter (410 nm) this study 24.3 1.8

Ringen C-L3924 24.1 1.9 ET blue OSL SAR quartz 4-11 --- U 340 this study

Romont C-L4157 26.0 2.1 < ET pIRIR 290 SAR polymineral 4-11 g = 0.47±0.28 % inteference filter (410 nm) this study

Romont C-L4157 24.5 2.1 < ET blue OSL SAR quartz 4-11 - - - U-340 this study

Ginseldorf GI27 25.9 3.9 < ET blue OSL SAR quartz 63-125 - - - Semrock HC377/50 + BG3 Schmidt 2014

Nussloch GI190 20.5 2 < ET green OSL SAR quartz 4-11 - - - Semrock HC377/50 + BG3 Wolpert 2015 Nussloch NUP4-0809 23.1 1.9 ET - E3 blue OSL SAR quartz 32-40 - - - U 340 Tissoux et al. 2010

Nussloch BT1016 27.5 1.8 ET - E3 blue OSL SAR quartz 4-11 - - - U 340 Gocke et al. 2014

Ages Tephra below the Eltville Remagen-Schwalbenberg C-L2897 23 2.3 ET - E3/E2 blue OSL SAR quartz 40-63 - - - U-340 Klasen et al. 2015a APPENDIX | 213

S5_Fig. 1: Dose response curves (single saturating exponential) and test dose response for selected natural aliquots of investigated samples.

214 | APPENDIX

S5_Fig. 2: Results of luminescence performance tests for samples RMT2_7 (Romont) and RGE-16 (Ringen), left quartz and right polymineral separates. Samples RGE-16 was taken from the same sedimentary unit (UPGa) below the ET. Uncertainties are given as 1-σ. The preheat plateau tests

(a, c) show constant De values for temperatures between 240-280 °C and up to 200°C within 2σ uncertainty. A temperature of 280°C was chosen for RMT3_6 and RMT2_7 and 260°C for samples

RGE-4. First-IR stimulation temperatures between 50-180°C lead to contant De for both samples

(b, d). For all samples, a first-IR stimulation temperature of 50°C was chosen for De measurements. APPENDIX | 215

Supplementary material Chapter 6

S6_1 Additional methods

Fieldwork and sampling strategy

At all sites, we documented the geomorphological setting, since it strongly influences the accumulation, relocation and preservation conditions of LPS (cf. Lehmkuhl et al., 2016). Profiles offering the largest thickness were chosen for sample collection. Luminescence samples were taken with stainless steel tubes from loess, paleosols and soil sediments. Within a 30 cm diameter, bulk samples were taken to determine the total environmental dose rate. Samples GZW from Garzweiler were taken from an LPS which was exposed in 2011 but yielded the same stratigraphic situation. Continuous high-resolution sampling (5-10 cm) was conducted for grain size and geochemical analyses. Samples for quick profiling using a SUERC portable OSL (pOSL) device were taken every 20 cm and at sedimentary boundaries by pushing small opaque film containers into the sediment.

CaCO3

The calcium carbonate (CaCO3) content of every sample was determined by a calcimeter working in accordance to the Scheibler method. By adding a 10% hydrochloric acid solution to the sample material the calcium carbonate converts into carbon dioxide (CO2), which causes changes in pressure conditions within the apparatus. The quantity of this pressure change is used to calculate the CaCO3 content (Schaller, 2000; ISO 10693, 1995).

X-ray florescence

For geochemical analyses, 0.8 g were taken from the dried and sieved down to < 63 µm sample material and mixed with 2 g of the wax binder Fluxana Cereox. The mixture was further homogenized and pressed into a pellet form at 19.2 MPa for 120s. To determine the element concentration of each sample an energy dispersive X-ray fluorescence (ED-XRF) spectrometer (SPECTRO XEPOS, SPECTRO Analytical Instruments GmbH) was used.

Portable OSL measurements

Portable OSL reader measurements were carried out using a SUERC portable OSL reader ce. The sample containers were re-opened in the laboratory under subdued red illumination. The outer ~2 cm of potentially light exposed soil was removed before decanting the samples into a small cup that is inserted into the portable OSL reader. Care was taken that each sample was of similar size and, more importantly, that the surface area of the sample (i.e., the area

216 | APPENDIX

exposed to the stimulation diodes) was even. The samples were not pre-treated and not dried prior to analysis.

The sample measurement sequence used here had 165 s duration comprising a 15 s background measurement (no diodes), followed by 60 s IR stimulation (IRSL). These measurements were immediately followed by another 15 s background measurement, a 60 s stimulation with blue diodes (blueOSL) and a final 15 s background measurement. All measurements were made using continuous-wave stimulation.

Data analysis was done using the analyse_portableOSL() function (Burow, 2016) of the R package Luminescence. When using the absolute signal intensity as an indicator of changes in its determining factors such as postdepositional age, luminescence sensitivity, local dose rate or degree of signal resetting experienced prior to deposition (Sanderson and Murphy, 2010; King et al., 2014), the comparison of bulk signals can be biased when individual signal curves decay at different rates. To account for the variance observed in the shape of the signal decay curves the IRSL and blueOSL signals were derived from the first 10 s of stimulation rather than taking the cumulative sum of the whole stimulation curve. IRSL/blueOSL ratios were calculated by dividing the sum of the signal of the first 10 s of IR stimulation by the signal sum of the first 10 s of blue light stimulation.

References

Burow, C. 2016. analyse_portableOSL(): Analyse portable CW-OSL measurements. Function version 0.0.2. In: Kreutzer, S., Dietze, M., Burow, C., Fuchs, M.C., Schmidt, C., Fischer, M., Friedrich, J. (2016). Luminescence: Comprehensive Luminescence Dating Data Analysis. R package version 0.7.0. https://github.com/R-Lum/Luminescence/tree/dev_0.7.0

Sanderson, D.C.W., Murphy, S., 2010. Using simple portable OSL measurements and laboratory characterisation to help understand complex and heterogeneous sediment sequences for luminescence dating. Quaternary Geochronology, 12th International Conference on Luminescence and Electron Spin Resonance Dating (LED 2008) 5, 299–305. doi:10.1016/j.quageo.2009.02.001

APPENDIX | 217

S6.2 Further results

S6-2_Fig. 1: Grain size distribution calculated with the Lorenz-Mie theory and visualized by heatmaps. For detailed information of grain sizes from the loess-palaeosol sequence Frankenbach, see Krauß et al. (under review). Every data point of the heatmap visualizes the vol % of grains determined with Lorenz-Mie theory for each of the 117 grain size classes recorded by laser diffraction.

218 | APPENDIX

S6-2_Fig. 2: Abanico Plots (Dietze et al., 2016) of quartz and feldspar equivalent dose distributions for all samples from the loess-palaeosoil-sequences Romont (West and East), Ringen and Frankenbach. Dashed lines depict the mean equivalent dose of the corresponding sample.

APPENDIX | 219

S6-2_Fig. 3: Change in signal brightness of quartz samples from all sites. The ratio of counts vs. total dose rate was used according to Schmidt et al. (2011). The early glacial humic soil complexes shows much brighter signals than the remaining sediments. In case of sample

RMT1_13, the De of 193.5 ± 9.7 Gy is lower than for the younger samples RMT1_3 (221.2 ± 11.3 Gy), RMT1_5 (201.8 ± 10.2 Gy) and RMT1_14 (202.6 ± 10.2 Gy).

220 | APPENDIX

S6-2_Fig. 4: Chlorine content in the loess-paleosol sequence Ringen determined by X-ray fluorescence. In the Dehner maar core, increased Chlorine contents corresponds with an increased content of volcanic heavy minerals (pers. observation P. Schulte, cf. Römer et al., 2016). Considering the OSL ages and the stratigraphic position, a correlation to the Wartgesberg Tephra (27,800 b2k, Förster and Sirocko, 2016) is likely.

Reference

Dietze, M., Kreutzer, S., Burow, C., Fuchs, M.C., Fischer, M., Schmidt, C., 2016. The abanico plot: Visualising chronometric data with individual standard errors. Quaternary Geochronology 31, 12–18. doi:10.1016/j.quageo.2015.09.003