FACULTEIT WETENSCHAPPEN Opleiding Master of Science in de geologie

Distinguishing between source areas of lacustrine turbidites triggered by the 1960 and 2010 great Chilean earthquakes

Nick Kiekens

Academiejaar 2015–2016

Scriptie voorgelegd tot het behalen van de graad Van Master of Science in de geologie

Promotors: Dr. M. Van Daele, Prof. Dr. S. Bertrand Leescommissie: Dr. Inka Meyer, Prof. Dr. Jasper Moernaut

Cover picture: View on the Guacho river delta, draining water from the Villarrica Volcano (background) into Lake Calafquén (Photo by Andrés García Prieto).

ACKNOWLEDGEMENTS

To start off, I would like to express my greatest thanks to both my promotors, Prof. Dr. Sébastien Bertrand and Dr. Maarten Van Daele, for giving me the chance to perform my MSc. thesis on such a fascinating subject. Furthermore, I would like to thank them for their amazing guidance throughout the whole project and their major effort on reading, correcting and rereading the manuscript, even when they were out of office.

I would also like to thank Elke Vandekerkhove for providing me with numerous papers on types and characteristics of lacustrine turbidites, and together with Zakaria Ghazoui for the tips and tricks on preparing the samples for carbon and nitrogen analysis.

I would also like to express my gratitude to the whole staff of the Renard Centre of Marine Geology for the usage of the equipment at their sedimentology lab (Dep. of Geology, Ghent University) and for their introductory software classes on Grapher, Strater and CorelDraw, saving me a lot of time figuring out how each program works. Thanks also go out to the staff of the marine biology lab (Dep. of Geology, Ghent University), who let me use their equipment during sample preparation.

Special thanks to the Stable Isotope Facility of the University of California, Davis for carrying out the carbon and nitrogen analyses as soon as possible and reducing the turnaround times for both sample series.

Last but not least, I would like to thank my family and friends for their endless support and patience during the more stressful times I encountered while finishing up this thesis.

Thank you all and enjoy reading!

TABLE OF CONTENTS

1. Introduction ...... 1 2. Setting ...... 3 2.1 Geomorphological setting ...... 3 2.2 Seismotectonic context ...... 3 2.3 Climatic context ...... 5 2.4 Lake setting ...... 5 2.4.1 Lake Villarrica ...... 6 2.4.2 Lake Calafquén ...... 7 2.4.3 Lake Riñihue ...... 7 2.4.4 Lake Rupanco ...... 8 2.4.5 Sedimentation ...... 8 3. Lacustrine turbidites ...... 11 3.1 Discriminating source areas ...... 11 3.1.1 Bulk organic geochemistry ...... 11 3.1.2 Sediment grain size ...... 14 3.2 Deposit types ...... 16 3.3 Reports and turbidite descriptions ...... 17 3.3.1 Lake Villarrica: VI4, VI8, VI18 ...... 17 3.3.2 Lake Calafquén: CGC1, CB4, CB9, CALA05, CALA08 ...... 18 3.3.3 Lake Riñihue: RI5, RI7, RI8 ...... 19 3.3.4 Lake Rupanco: RUP02BIS, RUP03TRIS, RUP04...... 21 4. Material and Methods ...... 22 4.1 Sediment cores and sampling ...... 22 4.2 Sample preparation ...... 23 4.3 Loss on ignition ...... 23 4.4 Carbon and nitrogen elemental and isotopic analysis ...... 23 4.7.1 Sample preparation ...... 23 4.7.2 Analysis at UC Davis Stable Isotope Facility ...... 24 4.8 Grain size analysis ...... 25 4.8.1 Sample preparation ...... 25 4.8.2 Analysis with Malvern Mastersizer ...... 25 5. Results ...... 27 5.1 Lake Villarrica ...... 27 5.1.1 VI4...... 27 5.1.2 VI8...... 27

5.1.3 VI18...... 28 5.2 Lake Calafquén ...... 30 5.2.1 CGC1 ...... 30 5.2.2 CB4 ...... 31 5.2.3 CB9 ...... 31 5.2.4 CALA05 ...... 32 5.2.5 CALA08 ...... 33 5.3 Lake Riñihue ...... 35 5.3.1 RI5 ...... 35 5.3.2 RI7 ...... 36 5.3.3 RI8 ...... 37 5.4 Lake Rupanco ...... 38 5.4.1 RUP02BIS ...... 38 5.4.2 RUP03TRIS ...... 39 5.4.3 RUP04 ...... 40 6. Discussion ...... 43

6.1 Correlation between LOI550 and TOC ...... 43 6.2 Relation between C/N atomic ratio and grain size ...... 45 6.3 Interpretation C/N atomic ratio and grain size ...... 47 6.3.1 Lake Villarrica ...... 47 6.3.2 Lake Calafquén ...... 50 6.3.3 Lake Riñihue ...... 52 6.3.4 Lake Rupanco ...... 54 6.4 Potential of C/N ...... 55 7. Conclusions ...... 56 8. References ...... 57 9. Nederlandstalige samenvatting ...... 65 10. Appendix ...... 69

1. INTRODUCTION

Understanding the source area of turbidites in lacustrine settings can improve interpretation of sediment cores and may aid in reconstructing slope failure processes or in comprehending the events responsible for the sediment deformation, such as earthquakes and floods. Many studies have already shown the potential, where records of turbidites and subaquatic landslides were used as an archive for reconstructing the paleo-earthquake history in different tectonic settings (e.g., Schnellmann et al., 2002; Migowski et al., 2004; Moernaut et al., 2007; Beck, 2009; Waldmann et al., 2011; Smith et al., 2013) and for modelling historical flood events during periods of high fluvial discharge (e.g., Czymzik et al., 2010; Wilhelm et al., 2012; Saitoh and Masuda et al 2013; Simonneau et al., 2013; Wilhelm et al., 2013).

In this thesis, the carbon-to-nitrogen (C/N) ratio is used as an alternative parameter to distinguish between the source areas of a series of turbidites from four different lakes in the Chilean Lake District (39°S-41°S), located in similar climate zones and with comparable morphological and limnological characteristics (Campos, 1984). These turbidites were simultaneously triggered by the 1960 Valdivia and 2010 Maule megathrust earthquakes along the Nazca-South American plate boundary. Well recorded eyewitness reports of the seismically-induced events (e.g., onshore landslides, mudflows, small-scale lake tsunamis, seiches, subsidence, absence of events) in and around the lake were used to compare core data and improve interpretation.

The C/N ratio represents the atomic ratio of organic carbon to that of nitrogen in a sample. It is widely and often used as a parameter in the analysis of sediment cores, and its most well-known application may be as a proxy in paleoclimate research. It is mainly utilised in lacustrine sediment cores, since organic material found in marine sediments holds information about the source before reaching the floor as well as after burial, next to the processes it was subjected to (Jasper and Gagosian, 1990; Meyers, 1994; Prahl et al., 1994). Algae in general have a C/N ratio of about 4 to 8, while higher land plants (phylum Tracheophyta) have C/N ratios of ≥ 20 (Premuzic et al., 1982; Jasper and Gagosian, 1990; Meyers, 1994; Prahl et al., 1994). In the Ocean, Emerson and Hedges (2003) observed that about 90 % of the organic matter produced at the surface is being degraded by bacteria while moving down the water column. After burial, sediment diagenesis degrades another 9 % of the organic carbon that sinks to the deep ocean floor, so that eventually only 1 % is permanently buried in the sediment. For lacustrine sediments on the other hand, sediment diagenesis does not have such an impact on the organic matter. Organic carbon isotope ratios do not seem to display significant diagenetic shifts. In a study by Rea et al. (1980) in Lake Michigan for example, δ13C values remained at 26‰ from modern to 3500-year old sediments in which organic carbon concentrations varied between 1 and 3%. Diagenesis also doesn’t have an impact on the integrity of the C/N ratio (Meyers and Ishiwatari, 1993). The change in elemental composition upon burial is not large enough to remove the vascular/non-vascular plant signals and this due to the refractory nature of terrestrial organic matter (Meyers and Ishiwatari, 1993; Meyers, 1994). Therefore shifts in the C/N ratio in a lacustrine sediment core can be interpreted as shifts in the organic source material, whether the organic carbon found in the sediment comes from land-based plants or rather has an algal origin (Ishiwatari and Uzaki, 1987). Furthermore, this ratio can be used to differentiate between certain groups of land-based plants, depending on the kind of carbon fixation pathway they follow (e.g., C3

1 and C4 plants). This makes it a useful tool for determining the source areas of organic matter in sediments. A more elaborated explanation can be found in section 3.1.1.

With this in mind, the goal of this thesis is to study to which extent the C/N ratio can be used to differentiate between source areas of lacustrine turbidites, such as hemipelagic slope failures, river- delta failure, onshore landslides surging directly into the lake, flood related events, mud flows, etc. A next step is to assess if there is any relation to the grain size distribution, as often the C/N ratio is closely related to the grain size of the clastic component of the sediment (Howarth et al., 2014). Eventually, if sediment-based data and historical reports show a consistent degree of correlation, it can be used as a proxy for long cores in future lacustrine paleo-seismic/-climate research.

In order to find an answer to these questions, 18 turbidites of known origin were sampled from a series of cores taken in different sedimentary environments in the lakes, which were collected during two separate field expeditions in 2009 and 2010. Samples were first prepared for the loss on ignition method, so the total organic carbon content could be estimated for subsequent carbon and nitrogen elemental and isotopic analysis preparation. In parallel, another identical series of samples were pre- treated for grain size analysis. Finally, the carbon-to-nitrogen ratios of all samples were compared to the delta values of 13C and to the mean grain size distributions, to determine the source of the sedimentary organic matter and to find a correlation between both, respectively.

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2. SETTING

2.1 GEOMORPHOLOGICAL SETTING

The study area is situated in south-central Chile and is focused on four large lakes in the Chilean Lake District. From north to south (Fig 1) there is Lake Villarrica (39.25°S), located about 700 km south of the capital Santiago in the Araucanía Region, followed by Lake Calafquén (39.52°S), Lake Riñihue (39.80°S) and Lake Rupanco (40.82°S). The latter is located about 175 km south of Lake Villarrica and 80 km north of the port city Puerto Montt in the Los Lagos Region. Four basic geomorphological zones can be distinguished from west to east: the Coastal Range (Cordillera de la Costa), the Intermediate Depression (Central Valley), the Precordillera and the Andean Cordillera (Fig. 1). All four studied lakes are positioned along a narrow band at the foot of the Andes, as a part of the Precordillera. The Intermediate Depression is separated from the Coastal Range and the Andean Cordillera due to a series of faults running north to south and shows a trend of decreasing altitude towards the south. Around the latitude of Lonconche (39.37°S), the Intermediate Depression is locally absent due to the eastward extension of the Coastal Range by the Bahía Mansa Metamorphic Complex, making up a terrain of harder pelitic schists, metagreywackes and oceanic type mafic metavolcanics (Duhart et al., 2001). The geomorphological units are oriented parallel to the coast and the subduction zone.

2.2 SEISMOTECTONIC CONTEXT

Tectonic processes in this region are a consequence of the ongoing oblique subduction of the Nazca Plate underneath the South American Plate along the Peru-Chile Trench. The Nazca Plate is bounded on the west by the Pacific Plate and to the south by the Antarctic Plate through the East Pacific Rise and the Chile Rise, respectively. The Nazca plate moves slightly east-northeast, relative to a stationary South American Plate, at a convergence rate varying from approximately 80 mm/yr in the south to approximately 70 mm/yr in the north with an average rate between these two plates estimated at 73.7 mm/yr (DeMets et al., 2010), which is among the highest worldwide. This subduction zone is geologically complex and generates a large number of earthquakes due to a variety of tectonic processes. Shallow earthquakes are a result of crustal deformation and subsequent mountain building in the overriding South American Plate, while the large interplate earthquakes are produced by a slip along the dipping interface of the subducting plate at depths up to 60 km (Comte and Suárez, 1995). A part of the stress from the oblique subduction is relieved along the 1000 km long Liquiñe-Ofqui Fault Zone, running along the Andean Cordillera in proximity of the studied lakes. It is dextral strike-slip lineament, separating the north-moving Chiloé sliver (6.5 mm/yr south of Puerto Montt) from the rest of the South American Plate (Cembrano et al., 2000; Wang et al., 2007; Melnick et al., 2009).

Since the 20th century, numerous magnitude 8 or greater earthquakes have occurred on the interface between the Nazca and South American plates. On May 22nd 1960, the great Chilean earthquake with a Mw 9.5 took place in southern Chile along the Valdivia seismotectonic segment (Métois et al., 2012). This earthquake is currently the largest instrumentally recorded earthquake in the world, with

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Fig. 1. Setting study area in South-Central Chile with map detail of the studied lakes. Epicentres, magnitudes and local seismic intensities for the 1960 and 2010 main events are marked in red and blue, respectively. 1960a: 21 May foreshock; 1960b: 22 May main event. Coseismic slip area (> 5 m) for the main 1960 and 2010 events after Moreno et al. (2009, 2012). Geomorphology and tectonic structures: CR, Coastal Range; ID, Intermediate Depression; AC, Andean Cordillera; A-N, Arauco Peninsula-Nahuelbuta Range; MS, Maule segment; VS, Valdivia segment; LOFZ, Liquiñe-Ofqui Fault Zone. Volcanoes part of the sediment catchment of the respective lakes are marked on the map detail. Adapted from Van Daele et al. (2015) a rupture length from Lebu to Puerto Aisen of around 1000 km (Cifuentes, 1989). On the Modified Mercalli (MM) Intensity Scale, Lake Calafquén reached the highest intensities of the studied lakes

4 with an intensity VIII (‘Severe’), while the other studied lakes were estimated at VII½ (‘Very strong’; Lazo, 2008; Van Daele et al., 2015). However, macroseismic intensities in different areas of the affected region can vary greatly depending on the type of soil, where tectonically depressed areas suffered heavier damage (Weishet, 1963). Hence, estimations that are made based on observed infrastructural damage should be looked at carefully. Numerous landslides were triggered, mainly on the steeper valley flanks of the Andes (Tazieff, 1960; Wright and Mella, 1963; Weishet, 1963), some resulting as turbidites in lakes downstream/-slope of the landslides (Van Daele et al., 2015). Especially the area of the studied lakes was hit by many onshore landslides. A probable cause for this local concentration of landslides may be due to the proximity to the Liquiñe-Ofqui Fault Zone. The fractured substrate in this area together with the presence of active volcanoes, which have formed thick and unconsolidated pyroclastic deposits, makes it prone to landslides (Weishet, 1963). A potential disaster was narrowly avoided as a landslide near the Tralcan Mount dammed the outflow of Lake Riñihue, resulting in a water level rise of 26 m, dangerously increasing pressure on the river dam downstream (Weishet, 1963). Other phenomena such as lake tsunamis and related seiches, were also observed in neighbouring lakes, e.g. Lake Rupanco (Weishet, 1963; Wright and Mella, 1963).

th On February 27 2010, another large megathrust earthquake occurred with a Mw 8.8 and a rupture length of 500-600 km, closing a seismic gap on the Maule segment that had not experienced a large megathrust earthquake since 1835 (Métois et al., 2012), just north of the Valdivia segment (Moreno et al., 2012). Macroseismic intensities for lakes Villarrica, Calafquén, Riñihue and Rupanco are estimated VI (‘strong’), V½, V (‘moderate’) and IV½ (light) respectively on the MM Intensity Scale, according to U.S. Geological Survey (2016) ShakeMaps. The 1960 and 2010 events are the most significant, but numerous other earthquakes struck the study area during the past century. These involve major foreshocks and aftershocks of the 1960 and 2010 main events, as well as dozens of other interplate earthquakes (Van Daele et al., 2015), but in this study the focus lies on the deposits of the 1960 and 2010 megathrust earthquakes.

2.3 CLIMATIC CONTEXT

The climate in this region is humid-temperate with mainly heavy rainfall during austral winter. Summers are cool due to cool ocean currents, while winters are milder than other climates in similar latitudes. Precipitation is driven by strong southern Westerlies, known colloquially as the “roaring forties”, and is slightly reduced during El Niño years (Heusser, 2003). Vegetation is heavily influenced by the Westerlies. The polar Pacific air becomes unstable as it cools and condenses on crossing the Cordillera de la Costa and on rising up the west slope of the Andean Cordillera, providing a lot of rain along these regions (Heusser, 1974).

2.4 LAKE SETTING

Lakes Villarrica, Calafquén, Riñihue and Rupanco (Fig. 1) are located in the northern half of the Valdivia segment between 39°S and 41°S. They fall within a similar temperate rainy climate zone, with or without a dry season. Vegetation’s carbon fixation type in this region is dominated by C3 carbon fixation, rather than C4. The reasoning behind this statement is that C4 plants (e.g. Cyperus rotundus, Cynodon dactylon, Eleusine indica) are more efficient in photosynthesis under hot, sunny,

5 dry conditions, but not under more temperate, moist conditions (Heusser, 1974; Sage et al., 1999b).

Therefore C3 plants are far more abundant in wetter, more temperate environments, as is the case for the study area. The type of carbon fixation utilised by the lake’s surrounding vegetation is an important parameter in the interpretation of C/N results, but more on this subject can be found in the methods section (section 3.3.1).

All four studied lakes show comparable morphological and limnological characteristics (Campos, 1984). The lake basins originate from glacial valley overdeepening during the Late Quaternary glaciations (Laugenie, 1982). They are all positioned at the western foot of the Andean Cordillera and dammed by a series of frontal moraines (Laugenie, 1982; Bentley, 1997). The overall bottom morphologies are characterized by a central deep basin and shallower areas in the western parts where several sub-basins, bedrock mounds, and moraine ridges are located (Moernaut, 2010; Van Daele et al., 2014b). The major river inflows are situated on their eastern boundary, where the coarsest fraction of their sedimentary load is deposited in the associated deltaic fans and in the proximal, deep basins through underflows (Moernaut et al., 2014). Their outflow is located at their western limits with the exception of Lake Calafquén, where the main outflow is situated east of its center. Important to note is that the lakes Calafquén and Riñihue are indirectly connected with each other through riverine systems and several other lakes. This has an impact on the sediment catchment area of each lake since they work as a sediment trap and thus reduce the sediment supply for the lakes downstream. A more detailed description of each lake’s characteristics can be found in the next paragraphs.

2.4.1 LAKE VILLARRICA

Lake Villarrica is located 215 m a.s.l. and stretches over a surface area of 174 km² (Table 1). It consists of a single central basin with a maximum depth of 167 m, with some shallower areas with more morphological variability in the southwestern part of the lake (SHOA, 1987). Vegetation in the lake’s surrounding area is dominated by a deciduous forest, with a transition to a more temperate evergreen macrobioclimate (Moreira-Muñoz, 2011). Deciduous broadleaved species such as of the Nothofagus (e.g. N. alessandrii, N. glauca) and Eucalyptus are abundant, mixed with evergreen coniferous trees such as those of the genera Araucaria, Laurelia, and Eucryphia (San Martín and Donoso, 1996). Undergrowth mostly exists of myrtaceous shrubs (e.g. Myrceugenella and Myrceugenia), along with genera like Rhaphithamnus, and Azara, and a variety of epiphytes (e.g. Luzuriaga radicans, Sarmienta repens, Hydrangea; Heusser, 1974). This rather dense vegetation together with the high amount of precipitation during austral winter suggests that the availability of easily erodible material in the sediment catchment is the controlling factor in sediment transport to the lakes (Van Daele et al., 2014). Lake Villarrica has a sediment catchment area of 2650 km² (Moernaut et al., 2009), which is by far the largest of the four studied lakes. The sediment catchment comprises the northern slopes of Villarrica, Quetrupillán, and Lanín (Van Daele et al., 2014). The Trancura River in its eastern extremity is the major river inflow and supplier of sediments in Lake Villarrica. On average, the sedimentation rate is determined at 1.5 mm/yr in the western sub-basins (Van Daele et al., 2014; Moernaut et al., 2014). The Toltén River in the lake’s western extremity cross-cuts the moraine ridges and regulates the outflow of the lake towards the Pacific Ocean.

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2.4.2 LAKE CALAFQUÉN

Lake Calafquén is located 204 m a.s.l. and extends over an area of 118 km² (Table 1). It exists of a large, deep basin with a maximum depth of 215 m depth, with a smaller sub‐basin situated in the southwestern part of the lake (SHOA, 2008). The climate and vegetation in this area is nearly identical to the one seen near Lake Villarrica, since they are in close proximity to one another (in straight line ca. 30 km). A subtle increase in transition to a more temperate climate vegetation with mixed forests might be observed, where evergreen angiosperm trees next to their deciduous specimens, as well as evergreen conifer trees, are more common. The catchment area of Lake Calafquén is 554 km² (Moernaut et al, 2009) and significantly smaller than the one observed in the nearby Lake Villarrica. The catchment consists of the southern slopes of Villarrica Volcano and the southwestern slopes of Quetrupillán Volcano (Van Daele et al., 2014). The main tributary of the Lake is the Llancahue River. An average sedimentation rate of 1 mm/yr was determined by Van Daele et al. (2014) and Moernaut et al. (2014) in the southwestern sub-basins. The outflow of the lake is controlled by the Pullinque River, leading to the Pullinque Lake.

2.4.3 LAKE RIÑIHUE

Lake Riñihue is situated 107 m a.s.l. and has a surface area of 90 km² (Table 1). It consists of a central basin with a depth up to 323 m and two western sub-basins (Campos et al., 1987). The area of interest for this lake lies in its more shallow western section, where Riñihue is cut into two arms by the Tralcán Mount. The same climate classification applies for the region around Lake Riñihue as for the previously discussed lakes, which is an oceanic temperate rainy climate were precipitation dominates during austral winter. The vegetation in the catchment can be classified as a Valdivian temperate (rain)forest. The forest is characterised by broadleaf tree species with evergreen, glossy and elongated leaves, mostly dominated by plants from the Lauraceae family and hence its other denomination as laurisilva. Some of its components are Aextoxicon punctatum, Laureliopsis philippiana, Dasyphyllum diacanthoides, Luma apiculate, Laurelia sempervirens, Eucryphia cordifolia and Weinmannia trichosperma intermixed with Nothofagus species (Moreira-Muñoz, 2011). The sediment catchment area of the lake is 382 km² (Van Daele et al., 2015), which is rather small compared to the other three lakes in this study. The reason for this is because it is the last basin in the Seven Lakes chain (Fig. 2). Lake Riñihue receives indirectly the water from the lakes Pellaifa, Calafquén, Pullinque, Panguipulli, Neltume and Pirihueico through riverine systems. All these lakes function as sediment traps, resulting in a relatively small sediment catchment. The primary source area for the detrital fraction of the sediment in this lake is the western flank of Mocho-Choshuenco Volcano (Laugenie, 1982). However, the elongated shape of the lake, and thus the relative proximity to the coastline of each location in the lake, makes the slopes bordering the coastline also important sediment suppliers. The main contributor to its water and sediment supply is the Enco River on its eastern side. A sedimentation rate of 1 mm/yr was calculated by Moernaut et al. (2014) for the western sub-basins. The San Pedro River in its northwestern extremity is the outflow, draining the water from the lake to the Pacific Ocean.

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Fig. 2. Structural image of the Seven Lakes’ hydrographic network.

2.4.4 LAKE RUPANCO

Lake Rupanco is located 123 m a.s.l. and has the largest surface of all four lakes, with an area extending over 231 km² (Table 1). It exists of a central basin reaching depths up to 269 m below lake level, and an eastern, southern and western sub-basin (SHOA, 2001). Climate conditions and vegetation change as the latitude shifts approximately one degree southwards in comparison with previously discussed Lake Riñihue. A temperate rainy climate still reigns these regions, but with significant precipitation during all seasons. Vegetation can be classified as a North Patagonian rainforest with predominantly evergreen species such as those of the broadleaf Nothofagaceae (e.g. Nothofagus dombey, N. nitida, N. betuloides) and conifers from the Podocarpaceae (e.g. Podocarpus nubigenus; di Castri and Hajek, 1976). Epiphytes densely cover trunks and branches and include species such as Griselinia scandens, Pseudopanax laetevirens, Asteranthera ovata, Philesia naagellanica, Mitraria coccinea, and a variety of filmy ferns (e.g. Hymenophyllum) and mosses. Shrubs (e.g. Lomatia ferruginea, Maytenus magellanica) are less abundant (Heusser, 1974). The sediment catchment of Lake Rupanco has an area of 629 km² (Van Daele et al., 2015). It comprises the northern flank slopes of the Puntiagudo Volcano and the western flank slopes of the Casablanca Volcano. The main tributaries to the lake consist of the Gaviotas River and the Bonito River. Van Daele et al. (2015) calculated an annual sedimentation rate between 1.1 to 2.85 mm. The outflow of Lake Rupanco is the Rahue River, which is located in its western extremity.

2.4.5 SEDIMENTATION

The hemipelagic sedimentation of all four lakes has been classified as a diatomaceous ooze with a small fraction of terrestrial organic matter, dispersed volcanic ash, and terrigenous clays/silts (Van Daele et al., 2014; Van Daele et al., 2015). Sedimentary sequences in general show annually deposited µm- to mm-scale laminations (i.e. varves; Boës and Fagel, 2008; Van Daele et al., 2014; Van Daele et al., 2015). The varved lake sediments consist of laminae of organic-rich clayey to silty terrestrial material deposited during increased winter river discharge and a lamina largely built of diatom frustules deposited in spring, when bloom of diatoms occurs due to winter turn-over (Moernaut et al., 2014). This depositional cycle has been broadly studied in the nearby Lake Puyehue (40.68°S) by Boës and Fagel (2008). Lakes Villarrica and Calafquén also show the occurrence of lahars during eruptions of the Villarrica Volcano. These mudflows contribute significantly to the sediment budget of the deep proximal basins and can leave thin, fine-grained deposits with a terrestrial composition in the more distal and shallower areas of the lakes (Van Daele et al., 2014). Tephra

8 layers, varve counts and 210Pb/137Cs radionuclide dating were used to construct accurate age-depth models for the lakes Villarrica, Calafquén, Riñihue and Rupanco (Van Daele et al., 2014; Moernaut et al., 2014; Van Daele et al., 2015). These were used to determine the timing of events causing observed lacustrine turbidites, so distinction could be made between turbidites of the 1960 and 2010 great Chilean earthquakes.

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Fig. 2. Slope-shaded SRTM map of Lake Riñihue & Lake Rupanco and their surrounding area with onshore reports, local seismic intensities, bathymetry, SEDs and coring locations. Used cores in this thesis are marked orange. Adapted from Van Daele et al. (2015)

Table 1. General information on setting, bathymetry, climate, vegetation and sedimentation rates for all studied lakes. *Sedimentation rates determined from master cores VILLSC01 (Villarrica), CAGC02bis (Calafaquén) and RINGC03 (Riñihue). See Figure 4 and 5 for location. Adapted from Van Daele et al. (2015)

Lake Latitude Longitude Altitude Lake Catchment Catch./lake Max. Bathymetry Climate Vegetation Sediment. Sediment. (°S) (°W) (m a.s.l.) surface area (km²) ratio depth (m) source (Köppen– rate rate source (km²) Geiger (mm/yr) class.) Villarrica 39.25 72.10 215 174 2287 13.1 167 SHOA (1987) Temperate Deciduous ca. 1.5 * Van Daele + RS rainy (Cfs) forest et al. (Moernaut et (2014a,b); al., 2014) Moernaut et al. (2014) Calafquén 39.52 72.18 204 118 555 4.7 212 SHOA (2008) Temperate Deciduous ca. 1 * Van Daele + RS rainy (Cfs) forest et al. (Moernaut et (2014a,b); al., 2014) Moernaut et al. (2014) Riñihue 39.80 72.38 107 90 382 4.3 323 Campos et al. Temperate Valdivian ca. 1 * Moernaut (1987) + RS rainy (Cfs) rainforest et al. (2014) (Moernaut et al., 2014)

Rupanco 40.82 72.50 123 231 629 3.0 269 SHOA (2001) Temperate N. 1.1-2.85 Van Daele rainy, Patagonion et al. (2015) without dry forest season (Cfb-c)

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3. LACUSTRINE TURBIDITES

Lake turbidites have already proven their importance as a tool for understanding sedimentary sequences and attributing a certain tectonic and depositional event to its origin, as they require at least a subaquatic slope and some sort of gravity process (loading), tectonism or other extreme event to trigger density-based (hyperpycnal) currents (e.g., Monecke et al., 2004; Strasser et al., 2006; Howarth et al., 2012 and 2014; Moernaut et al., 2014). The sediment archives containing these rapidly deposited layers can represent a high resolution record of seismicity and terrestrial flood events, depending on the supply of (terrestrial) sediment sources (Goldfinger et al., 2012). Furthermore, they can provide chronologic evidence of the frequency of landslides and the earthquakes that probably triggered them by using radiocarbon dating or varve counting above and below the turbidite (Strasser et al., 2006; Moernaut et al., 2007; Enkin et al., 2013).

3.1 DISCRIMINATING SOURCE AREAS

3.1.1 BULK ORGANIC GEOCHEMISTRY

As palaeo-environmental and source information are preserved in the molecular, elemental and isotopic compositions of organic matter, C/N ratios have often been used to differentiate between algal and land plant origins in sedimentary organic matter (Prahl et al., 1980; Premuzic et al., 1982; Ishiwatari and Uzaki, 1987; Jasper and Gagosian, 1990). Marine and lacustrine algae typically have atomic C/N ratios in the range of 4 to 8 (Redfield ratio), in contrary to the vascular land plants, which have C/N ratios of ≥ 20. The contrast arises due to compositional differences in the organic matter produced by both groups. Aquatic algae are typically protein-rich and cellulose-poor, while vascular land plants are protein-poor and cellulose-rich. These nitrogen-rich proteins together with the lack of carbon-rich cellulose are responsible for the relative lower C/N ratios for aquatic algae and vice versa for the relative higher C/N ratios in vascular plants.

Carbon isotope ratios have already been proven useful to distinguish between marine and continental plant sources of organic matter in sediments and to identify the different source types of land plants (e.g., Hunt, 1970; Newman et al., 1973; Gearing et al., 1977; Prahl et al., 1980; Premuzic et al., 1982). Higher land plants can be subdivided into 4 major groups based on their type of carbon assimilation. Most photosynthetic plants incorporate carbon following the C3 carbon fixation (Calvin pathway), which biochemically prefers incorporation of 12C to produce a δ13C shift of -20 ‰ from the isotope ratio of the inorganic carbon source (Meyers, 1994). They comprise about 85 % of all terrestrial plant species (Simpson, 2010) and include most trees and small seeded cereal crops. Some plants use the C4 carbon fixation (Hatch-Slack pathway). Here carbon is fixed that is significantly enriched in 13C, which creates a diffusional isotope shift of -7 ‰ (Meyers, 1994). Only about 3 % of all plant species are thought to employ a C4 carbon fixation, of which mostly grasses and sedges (Simpson, 2010). Another group comprising 8 % of all terrestrial plants uses the Crassulacean acid metabolism (CAM; Simpson, 2010). This type of carbon fixation was developed as an adaptation for dry, desert habitats. The residual 4 % does not use oxygenic photosynthesis to fix carbon in their structure, but relies on a heterotrophic lifestyle (e.g. symbiotic, parasitic) where carbon is not fixed, but rather used for growth. However, CAM plants and the residual heterotrophic plants are not of importance in this study and will not be mentioned further throughout this thesis. Organic matter

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13 produced from atmospheric CO2 (δ C ≈ -7 ‰) by land plants following the C3 pathway consequently 13 is in the δ C-range of -30 to -25 ‰, with an average of -27 ‰, and by those following the C4 pathway between -15 to -10 ‰, with an average of -14 ‰ (Fig. 3; O'Leary, 1988).

Fig. 3. Representative elemental and carbon isotopic compositions of sedimentary organic matter from lacustrine algae, C3 land plants and C4 land plants that use carbon fixation during photosynthesis. Adapted from Meyers and Lallier-Vergés (1999)

In this thesis, the usefulness of the C/N ratio is tested for recognizing the source area of lacustrine turbidites (e.g. reworked hemipelagic-slope sediments, terrestrial/deltaic source area). As the analyses were executed on samples from lacustrine turbidites, originating from source areas with both a composition similar to the laminated hemipelagic sediments or more terrestrial influenced, we can expect δ13C-values in the range of -25 to -30 ‰ This range corresponds with values for all the aquatic organic matter and land plants using the C3 carbon fixation. Since both lie in the same range, δ13C-values won’t be of any use in the distinction of source areas. C/N ratios on the other hand are the variable of interest. These will range between the end members of lacustrine algae (4 to 8) and C3 plants (≥ 20), depending on the influence of terrestrial material.

In a study by Simonneau et al. (2013) in Lake Ledro (southern Alps, Italy), a distinction is made between turbidites triggered by earthquakes and flood events based on C/N and the hydrogen index (HI). They have combined high-resolution seismic profiles and sediment cores from the lake’s catchment area and the riverbed to assign different turbidites from the Holocene to a certain triggering event, i.e. earthquakes and floods. Cores of the lake showed that background sedimentation is laminated and exists of millimetric to inframillimetric couplets of discrete white calcite layers and brown organic layers, typical of calcite varves (Lotter and Lemcke, 1999; Brauer et al., 2008; Czymzik et al., 2010) reflecting summer (main eutrophication phase resulting in higher diatom productivity) and winter (deposition of detrital and amorphous organic material). These regular couplets are sporadically interrupted by two types of SEDs. On one hand, there are light-

12 coloured massive layers, on the other hand dark-coloured graded beds. Based on analysis of the organic matter present in the background of the lake and riverbed samples, together with lake sediment bulk density and grain size analysis, Simonneau et al. (2013) concluded that the light- coloured layers are composed of a mixture of lacustrine sediments, containing mostly algal particles similar to the ones observed in background sediments (low C/N), while the dark-coloured layers mainly consist of terrestrial organic matter from soils and land plants (high C/N), which is the same organic signature as the samples taken in the watershed. In contrast to light-coloured, earthquake triggered, turbidites, they usually do not contain a visible trace of hemipelagic background sedimentation. These observations were confirmed by determining the HI values for both types of SEDs. For the light-coloured layers these values (< 300 mgHC g−1 TOC) indicate that the organic matter is more degraded than those in the background sediments. This suggests that these lighter layers are made up of older reworked background sediments, which lead to their interpretation as subaquatic mass-movements triggered by historical and pre-historical regional earthquakes. For the dark-coloured SEDs in Lake Ledro, these HI values (<<< 300 mgHC g−1 TOC) suggest very little maturation.

Previously discussed earthquake triggered turbidites all had a subaquatic sediment source, where mainly background sediments were mobilised due to slope failure and subsequently redeposited. In a study executed by Howarth et al. (2012) in Lake Paringa (South Island, New Zealand), a closer look is taken at megaturbidite formation and turbidites resulting from hillslope landslides in the lake’s catchment. A sedimentary sequence existing of a megaturbidite overlain by a series of smaller turbidites was analysed. The megaturbidite contains a basal unit of normally graded fine sandy silt, with above a layer of homogeneous very fine sandy silt, and a cap of medium silt. The fine sandy silt base is explained as the deposition of a traction carpet, while the homogeneous very fine sandy silt above was thought to be the result of material ejected into the water column settling down and being reworked to the center of the basin by seiching. The medium silt cap is the eventual deposition of the finest material that remained in suspension. Analysis of organic carbon and nitrogen content showed a TOC = 3.5 % ± 1.9 % and C/N = 18.4 ± 2.8, which is in the range for mixed aquatic and terrestrial sources (10-20; Meyers, 1997) and fits the interpretation of a lake delta slope failure.

The overlying stacks of as much as thirty turbidites have a basal unit of inversely graded very fine sandy silt, gradually transitioning into a layer of normally graded medium silt, which is consistent with the deposition from hyperpycnal flows formed from sediment-loaded flood deposits (Mulder and Alexander, 2001). Also, these stacks of turbidites have a greater clastic sediment mass than all other types of deposits encountered. Carbon and nitrogen elemental and isotopic analysis data reports gave a TOC = 4.3 % ± 2.8 % and C/N = 29 ± 5 for the basal unit and a TOC = 3.8 % ± 2.0 % and C/N = 22.3 ± 2.9 for the upper unit. The high sediment supply is interpreted as the result of postseismic erosion of landslide debris in the catchment area, which is backed up by the high C/N ratios of turbidite sediments, pointing to organic matter derived from land plants (> 20; Meyers, 1997).

Both deposits, the megaturbidite and the stacks of overlying turbidites, are seen as a part of a repeating sequence in a seismic cycle. The megaturbidite’s sedimentology, thickness, and ponding geometry is consistent with a coseismic deposition as a result of subaqueous mass wasting accompanied by seiching (Beck, 2009; Schnellmann et al., 2002), followed by a postseismic landscape

13 response due to erosion. These sequences are topped by an aseismic, normal period of sedimentation. This study from Howarth et al. (2012) gives valuable new insights in the duration and magnitude of a postseismic response of a mountain landscape to large earthquakes, moreover, it gives a first record of a postseismic response similar to successive large earthquakes.

Based on the tremendous number of aligned studies available today, it is safe to conclude that the C/N atomic ratio is a very useful and valuable parameter in determining the source area of a turbidite.

3.1.2 SEDIMENT GRAIN SIZE

Grain size trends in turbidites have also been used in the literature to determine their provenance, therefore grain size analyses of all turbidites were conducted. In a first instance because grain size distribution and variations throughout a turbidite may provide important information about the origin (e.g. reworked hemipelagic sediment point to subaquatic slope failure; abundance in coarse material may suggest delta failure or landslides; inverse grading may propose a flood event) and flow conditions of a turbidity current. In a study by Mulder et al. (2001), the flow regimes responsible for a classical fining-upward bed and a basal coarsening-upward unit are explained. They concluded that a normally graded sequence represents a typical deposit of a decreasing flow (Komar, 1985; Kneller, 1995). Due to a continuous decline in flow energy with time and distance, a graded succession of sedimentary facies (Ta, Tb, Tc, Td and Te) is deposited above a surface with often contrasting sedimentation (e.g. hemipelagic sediments) and an erosive contact. This sharp basal contact is the result from the erosive waxing head of the flow (Middleton and Hampton, 1973). The typical graded deposit is called a Bouma sequence (Bouma, 1962). Ta-d describes the falling out of the coarse fraction (Ta), followed by deposition of less coarse material (i.e. sand to coarse silt fraction) as the energy of the turbidity current decreases and traction and saltation processes are not enough to transport the sediment particles (Tb, Tc, Td). Te is the last layer deposited in a Bouma sequence. It arises from the settling of the finest fraction in suspension (i.e. clay) where approximately no current exists and represents deposition of the tail of the flow, intermixed with the ongoing normal hemipelagic sedimentation. Absence of one or more facies within a Bouma sequence can be attributed to the proximal or distal location to the observed event or due to the grain size of the sediment transported in such current (e.g. lack of coarse material in source sediment). These normally graded beds are the result of short-duration, unsteady hyperpycnal currents (Laval et al., 1988). The sharpness of the basal contact, the intensity of erosion of the underlying deposits, and the size of the transported grains depends on the energy of the event (Mulder and Alexander, 2001).

Beds with a basal coarsening-upward unit can have several origins. In a first case, mud clasts can be incorporated in the base of a turbidite deposit. This will result in a local decrease in mean grain size for the coarse fraction in a regular Bouma sequence. The phenomenon is described in the Var turbidite system observed in the Ligurian Sea (northwestern Mediterranean) and consequently gives a layer with a millimetre-to centimetre-thick inverse grading, without any structure (Migeon et al., 2001). Another way to obtain a basal coarsening-upward unit, is by a two-layered turbidity flow. Here, a basal laminar boundary layer moves below a turbulent top layer. In the basal layer, the velocity of the flow is lower at the bottom than the top due to friction. This results in an inverse grading within the flowing basal layer, since the size of the carried particles is proportional to the

14 velocity (Lowe, 1982), and is followed by coarser grains falling out of the turbulent top layer as the energy of the flow decreases. The top of such turbidite deposits follow regular grading. These basal coarsening-upward layers are always structureless and usually contain coarse particles (Mulder and Alexander, 2001). A third type of basal coarsening-upward can be induced by a depletive waxing flow (Kneller, 1995). Such hyperpycnal flow can be produced by a steadily growing discharge at a river mouth, but only if the concentration of sediments is high enough (i.e. flood event). As long as the flow velocity is below the erosion threshold, a coarsening-upward facies is deposited (Kneller and Branney, 1995). Particles initially transported by a waxing flow are smaller (i.e. clay-silt fraction), but increase in grain size as the flood event becomes stronger and coarser grains are brought into suspension. These deposits often show sediment structures, such as current ripples.

In the study by Simonneau et al. (2013) in Lake Ledro, discussed in the previous section (3.1.1), grain size is also used to make a distinction between earthquake-triggered turbidites and flood events. Laser-diffraction grain size and bulk density analyses in these deposits clearly indicate that most of their bases are successively inversely and normally graded, which is a typical signature of more intense hyperpycnal flood deposits in a subaquatic basin (Mulder and Alexander, 2001; Mulder et al., 2003; Mulder and Chapron, 2011; St-Onge et al., 2012). These successive coarsening upward and fining upward sequences are correlated to the rising and the falling limb of a flood hydrograph and will be discussed more into detail in the next section of this chapter (section 3.1.2). This lead to the interpretation of the dark-coloured layers as deposits originating from strong hyperpycnal flood events.

A study by Beck (2009) in Lake Anterne (northern Alps, France), a relatively small simple lacustrine basin with on its south-eastern boundary a Gilbert-delta, gives more insight in the characteristics of turbidites originating from floods driven primarily by spring/summer snow melting, and slump turbidites resulting from slope failure of the steep delta foreset by gravity reworking processes (overloading) or triggered by earthquakes. Since both show a rather similar organic matter signature (i.e. organic matter from land plants), other parameters need to be involved to differentiate between both. Gravity cores were taken along a profile proximal to distal from the delta foreset base, containing thicker layers intercalated within the finely laminated sequences. These thicker layers were interpreted as results of hyperpycnal flow deposits and were sampled and analysed for grain size. Analysis showed that these beds clearly follow two different pathways on binary diagrams relating skewness with sorting (SK/SO) and the coarse 99th percentile with the median (Passega’s diagram; Passega, 1964). Beck (2009) concluded that slump turbidites typically have a coarser and poorly sorted base, where the transition from the coarse base to the fine-grained top is rather sharp. Furthermore, the granulometric contrasts appear reduced within the normal annual laminae. Flood turbidites on the other hand are directly associated to the concentration of watershed runoff by- passing the delta topset and foreset and rather stay in the grain size range of the regular annual lamination, but with a slightly coarser mean grain size at the base. In contrary to slump turbidites, strong flood related deposits have a well to moderately sorted base and typically consist of a coarsening upward sequence (Beck, 2009). Though, different types of flood deposits can occur on a smaller scale, depending on the load and related depositional process:

A less intense flood deposit may solely have a normal graded base, still pointing to a hyperpycnal current (Mangili et al., 2005). It can enter the lake as an underflow due to the amount of suspended

15 matter and/or factors such as temperature (e.g. glacier runoff is relatively colder than its catchment basin). While the turbidity current is spreading within the lake basin, the density difference will reduce leading to a decreasing transport capacity and consequently finer grain sizes on distal locations. This type of graded detrital deposit has a characteristic proximal-distal pattern, being thicker and coarser at the river mouth and thinning out along its course towards the central basin of a lake (Siegenthaler and Sturm, 1989).

Silt‐clay layers may be deposited when fine silt and clay detrital material is transported into the lake by low‐density currents. These currents will continue their course into the water column as over‐ or interflows (Sturm and Matter, 1978; Mangili et al.,2005) and eventually, the fine‐grained material sinks and deposits within a few days on the lake bottom (Siegenthaler and Sturm, 1989). Sometimes these layers may show some kind of faint grading. Another interpretation for this layer type, is that it might reflect the distal deposits of high‐density currents from which the coarser fraction has already been deposited (Mangili et al., 2005).

In some cases, layers are encountered containing various detrital and reworked sediment components (e.g. littoral calcite, diatom frustules, plant remains) that are well mixed within the sediment matrix (Czymzik et al., 2010). These are commonly thought to originate from major slope failures or debris flows. An alternative explanation for the formation of these matrix-supported detrital layers could be a strong river runoff event, where underflows have eroded material of the delta topset and littoral zone of the lake, instead of by-passing it (Czymzik et al., 2010).

3.2 DEPOSIT TYPES

Sampled sediments can be divided into two major groups of deposits. All turbidites sampled in this study are seismically-induced event deposits (SEDs) and sporadically interrupt the regular hemipelagic “background” sedimentation, which is not influenced by earthquakes or any other sudden or extreme event. The hemipelagic sediments have been described as fine-grained hemipelagic sediments composed of laminated diatomaceous muds. The SEDs have been further subdivided into three types of lacustrine turbidites (LT) based on their structure, grain size and composition (colour, magnetic susceptibility, XRF signature and microscopic composition).

Two of these types of lacustrine turbidites can be differentiated from each other by comparing their composition, being either similar to the hemipelagic sediment (LT1 type) or different from it (LT2 type) (Moernaut et al., 2014; Van Daele et al., 2015). They typically have a Ta and/or Te Bouma division (Bouma, 1962). The LT1 type is produced by failure of lateral slopes of up to 20° (Adams et al., 2001; Håkanson and Jansson, 2002; Strasser et al., 2011) and thus largely exists of reworked hemipelagic sediments. Usually they are well-sorted and appear as a homogenous deposition with a very thin, slightly more coarse base of fine sand fraction (< 2 mm thick; Ta-d) and a thin fine-grained top of fine to medium silt (< 5 mm thick; Te), as determined by Van Daele et al. (2015). The LT2 type usually contains coarser grains and is mostly poorly sorted in comparison to the LT1 type. Typically a more terrestrial, organic richer imprint can be found. This more heterogeneous composition and grain size distribution results in a homogenous to well-graded deposition with a Ta-b, Tc and/or Td division, and a Te division (Van Daele et al., 2015). Source areas related to these types of lacustrine turbidites could possibly be a river delta or relatively shallow near-shore areas, onshore landslides

16 that surged directly into the lake or that reached the lake in a more indirect way by means of debris flows, mud flows or even floods.

The third type of turbidite has one or more Ta-d divisions and a thick (> 10 cm) Te division. These are obviously thicker than the turbidite types described in the previous paragraph and are classified as a megaturbidite (Van Daele et al., 2015). Their base exists of coarse grains (Ta-d) with above a thick package of homogenous mud and on top a fine-grained clay to fine silt layer (Te). The source area of a mass-wasting can occur onshore as well as offshore and is usually large enough to cause a lake tsunami and potentially trigger a related seiche. Grain size fluctuations at the base of the homogenous mud and the ponding geometry of the deposit have been attributed to the fluctuating bottom currents associated with a lake seiche (Chapron et al., 1999; Schnellmann et al., 2006; Bertrand et al., 2008a; Beck, 2009; Mulder et al., 2009).

3.3 REPORTS AND TURBIDITE DESCRIPTIONS

3.3.1 LAKE VILLARRICA: VI4, VI8, VI18

1960 According to the reports following the 1960 Valdivia earthquake, water rose north of Pucón (i.e. eastern extremity of the lake; Fig. 4) while simultaneously dropping south of it. About fifteen minutes after the observation, the lake level returned to its normal steady state. Water was also reported to be “boiling” north of Pucón. Furthermore, numerous sightings of subsidence of beaches and deltas around the lake were reported, but no major landslides were triggered in the catchment area of the lake (Weischet, 1963; Sievers, 2000). In the cores taken in the southwestern sub-basin (VI4, VI8), LT1 type turbidites are present (Van Daele et al., 2015). In core VI18, taken to the west of the ridge in the southeastern part of the lake, the deposit attributed to the 1960 earthquake was not cored.

2010 Reports state that a small tsunami occurred on the lake after the earthquake. In its eastern extremity, near Pucón, a 2-3 m water level drop was witnessed instantly after the earthquake, followed by a rise of 1-1.5 m above its regular steady state with an incoming wave. Shortly after this oscillation, the water level returned to normal. Near-shore buoys of harbours in the area around Pucón were pulled below the water line due to subsidence. Subsidence was also observed south of the Trancura River inlet, where the beach disappeared completely. In the lake’s western extremity (i.e. harbour of Villarrica), a water level rise of around 80 cm was reported immediately after the earthquake, with subsequently a drop before returning to its normal steady state. During the earthquake, sand blows were also noted on the beach of Villarrica town, suggesting liquefaction of the (partially) saturated soil. All reports combined point in the direction of a small tsunami propagating from east to west. Though, the event was not strong enough to create a lake seiche. No landslides or other alterations were observed in the catchment area of the lake (Van Daele et al., 2015). The cores taken in the southwestern sub-basin (VI4, VI8) contained some small (~ 1.5 cm) LT1 deposits (Moernaut et al., 2014). In the southeastern part of the lake (VI18) an LT1 is covered by an LT2 , suggesting two density flows from a different source have reached this location (Van Daele et al., 2015).

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Fig. 4. Slope-shaded SRTM map of Lake Villarrica and Lake Calafquén and their surrounding area with onshore reports, local seismic intensities, bathymetry, SEDs and coring locations. Used cores in this thesis are marked orange. Adapted from Van Daele et al. (2015)

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3.3.2 LAKE CALAFQUÉN: CGC1, CB4, CB9, CALA05, CALA08

1960 In contrary to Lake Villarrica, the catchment area as well as the shores of the eastern sub-basin of Lake Calafquén were subjected to a lot of landslides (Fig. 4). Reports state that impact of these landslides on the water surface triggered a main wave, followed by some small secondary waves in the upper eastern end of the lake (Weishet, 1963; Wright and Mella, 1963; Sievers, 2000). Core CALA05, taken in the southwestern sub-basin, contains an LT1 type turbidite attributed to the 1960 earthquake. In the eastern (CB4) and western (CB9) sub-basins of the lake, mass-transport deposits occur. These are overlain by respectively one and two LT2 type turbidites, as determined by Van Daele et al. (2015). Another core was taken in the eastern sub-basin (CGC1), a few hundreds of meters southeast of CB4’s location. The base of the core shows a part of the LT2 type turbidite also found in CB4, but a part is missing due to insufficient coring depth. In core CALA08, the deposits attributed to the 1960 earthquake were not cored.

2010 Around the lake local near-shore subsidence was observed. Reports state that east of the peninsula near Lican Ray, some buoys got submerged as a consequence of subsidence. West of the peninsula no reports were made of disappeared buoys or other events attributed to subsidence. Large standing waves were witnessed during the earthquake in Coñaripe. Sequentially, the water level of the lake rose about one meter above its regular steady state before returning to its previous level. Furthermore, the shoreline moved more landward after the earthquake, suggesting subsidence (Van Daele et al., 2015). For the core taken in the southwestern sub-basin (CALA05) an LT1 type turbidite was found as a consequence of the 2010 earthquake (Moernaut et al., 2014). Cores (CALA09, CALA10; not used in this study) taken in the eastern sub-basin contain a mass-transport deposit covered by a rather heterogeneous LT2. More to the center of this basin, this same LT2 becomes more homogenous, were CALA08 is located (Van Daele et al, 2015).

3.3.3 LAKE RIÑIHUE: RI5, RI7, RI8

1960 No tsunami-like effects were reported for Lake Riñihue, though major landslides occurred near the lake, resulting in a blockage of the outflowing San Pedro river (Fig. 5). As a consequence of this natural dam formation attributed to the 1960 earthquake, the water level of the lake rose 26.85 m during 63 days. The rise resulted in a connection between the neighbouring Lake Panguipulli. A sudden dam breach could have had disastrous implications and would have destroyed all towns along the course of the river, including the city of Valdivia. To avoid destruction of these cities, an enormous manpower was put to service to control the outflow of the lake, called the Riñihuazo. Despite the effort, the towns of Los Lagos, Antilhue, Pishuinco and the riverside areas of Valdivia partially flooded (Davis and Karzulovíc, 1963; Weishet, 1963; Wright and Mella, 1963; Sievers, 2000). The cores used in this study (RI5, RI7, RI8) were taken in the western sub-basin of the lake and all showed an LT1 type turbidite (Moernaut et al., 2014). For core RI7, which was taken in the northwestern part of this sub-basin, southeast of a small delta on the northern shore, an LT2 was found below the LT1. The LT2 type turbidite exists of a 3.5 cm thick graded turbidite with a coarse

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Fig. 5. Slope-shaded SRTM map of Lake Riñihue and Lake Rupanco and their surrounding area with onshore reports, local seismic intensities, bathymetry, SEDs and coring locations. Used cores in this thesis are marked orange. Adapted from Van Daele et al. (2015)

20 sandy base. Only the top (~ 1 cm) could be classified as a LT1. More distal to this location (RI5), the LT2 becomes thinner (~ 2.5 cm), while the LT1 becomes thicker (~ 5.5 cm; Moernaut et al., 2014).

2010 No reports were made of any unordinary events in or around the area of Lake Riñihue, which could be attributable to the lack of witnesses present in the surrounding of the lake. Few people still live near the coastline since the 1960 event. The only core in this study where deposits attributed to the 2010 earthquake were found, is core RI7. This core is located southeast of a small delta on the northern shore of the northwestern sub-basin, where a 3 cm thick graded LT2 type turbidite was found.

3.3.4 LAKE RUPANCO: RUP02BIS, RUP03TRIS, RUP04

1960 Numerous landslides were triggered by the 1960 earthquake. Some of which dumped directly into the lake, others converged on land into mudflows and subsequently surged into the lake after the earthquake, as is the case at two locations in its eastern extremity (Fig. 5). An LT2 that covers a poorly developed fine-silt cap was encountered by Van Daele et al. (2013) at the top of the megaturbidite. This indicates that the arrival of the LT2-forming turbidity flow (mudflow) was noticeably delayed from the formation of the megaturbidite, but also that the LT2 was deposited not too long after the formation of the megaturbidite. As a consequence of these landslides surging directly into the lake, a large lake tsunami occurred strong enough to oscillate back and forth, creating a seiche event. Subsidence effects were also noted as many narrow beaches around the lake disappeared (Weishet, 1963; Wright and Mella, 1963). Cores were taken in the eastern sub-basin (RUP02BIS), in the western sub-basin (RUP03TRIS), and in the southern sub-basin (RUP04) of the lake. RUP02BIS contains a > 58 cm thick megaturbidite, covered by two relatively small (4 and 4.5 cm) LT2 type turbidites. The megaturbidite was also encountered in other cores taken in the central basin. In the western sub-basin, the megaturbidite is not present anymore and an LT1 is found with a thickness of 7.5 cm. Core RUP04 holds a 13 cm thick LT2 turbidite.

2010 Since the Rupanco cores available for this study were collected during an expedition in 2009, there is no data available on the SEDs triggered by the 2010 megathrust earthquake.

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4. MATERIAL AND METHODS

4.1 SEDIMENT CORES AND SAMPLING

The gravity cores used in this study were acquired during two field expeditions in the years 2009 and 2011 (Table 2). Subsequently, they were shipped to Belgium, opened, described and photographed in high detail, and further analysed (Van Daele, 2013; Moernaut et al., 2014; Van Daele et al., 2014; Van Daele et al., 2015). Both earthquakes studied here are relatively recent events, thus the sedimentary deposits resulting from these should show little to no burial. Deposits due to the 2010 Maule earthquake are assumed to occur at the very top of the cores taken in early 2011. Deposits from to the 1960 Valdivia earthquake were dated by intra-lake correlation with previously dated cores from other studies, by varve counting or by inter-lake correlation based on tephra marker horizons by Van Daele et al. (2015).

For this thesis study, turbidites attributed to the 1960 and 2010 megathrust earthquakes were sampled continuously on the working half of fourteen cores from four different lakes of the Chilean Lake District. Hemipelagic sediments were also sampled twice for each sampled turbidite, in order to have a better understanding of the regular aseismic sedimentation. For turbidites with a thickness of ≤ 8 cm, a sample interval of 0.5 cm was used. For turbidites with a length exceeding 8 cm (e.g. CB9), a sample interval of 1 cm was used. An exception is core RUP02BIS, which was sampled every 5 cm due to its length with a sample thickness of 1 cm. The samples of hemipelagic sediment have a thickness of 1 cm. In some cases, fungus was present on the foil-covered top of the core. This was first removed with a glass slide or spatula before sampling took place.

Table 2. General information for all cores used in this thesis and thickness of the seismically-induced event deposits that were attributed to the 1960 (red) or 2010 (blue) earthquake. Lake turbidite type 1: LT1; Lake turbidite type 2: LT2; Megaturbidite: MT. Adapted from Supplement Van Daele et al. (2015)

Lake Core name Sampling Lat. Long. Depth Length Thickness of deposits (cm) year (°N) (°E) (m) (cm) 1960 2010 LT1 LT2 MT LT1 LT2 Villarrica VI4 2011 -39.28 -72.19 85 81 2 1 VI8 2011 -39.28 -72.16 113 95 5 1 VI18 2011 -39.28 -72.08 154 21 3 2.5 Calafquén CGC1 2009 -39.56 -72.06 178 25 4 CB4 2009 -39.55 -72.06 173 54 6 CB9 2009 -39.53 -72.14 170 45 9 + 7.5 CALA05 2011 -39.55 -72.18 88 119 4.5 1.5 CALA08 2011 -39.52 -72.15 194 20 12 Riñihue RI5 2011 -39.80 -72.39 121 62 5.5 2.5 RI7 2011 -39.79 -72.39 118 62 1 3.5 3 RI8 2011 -39.79 -72.40 118 73 5.5 Rupanco RUP02BIS 2009 -40.88 -72.24 262 81 4 + 4.5 > 58 RUP03TRIS 2009 -40.82 -72.51 268 44 10 RUP04 2009 -40.87 -72.49 97 59 13

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4.2 SAMPLE PREPARATION

All 218 samples were dehydrated prior to analysis in the sedimentology lab (Dep. of Geology, Ghent University). This was achieved by lyophilisation. By freezing the soil material and then reducing the surrounding pressure, ice in the material is allowed to sublimate directly from the solid phase to the gas phase. This dry sediment state was necessary for later application in C/N analysis. After freeze- drying, samples were grinded and homogenised in an agate mortar.

4.3 LOSS ON IGNITION

Loss on ignition (LOI) is a commonly used method to estimate the organic and carbonate content of sediments. It provides a fast and inexpensive tool with a precision and accuracy comparable to other, more sophisticated geochemical methods (Dean, 1974). LOI is based on sequential heating of the sediment samples at specific temperature ranges in a muffle furnace, resulting in a weight loss closely related to the amount of organic matter and carbonates. Organic matter is oxidised at temperatures around 550°C to CO2 and ash. In a second reaction at temperatures around 950°C, transformation of carbonates result in CO2 and oxides. The latter heat treatment was not necessary for this study, since the only interest was an estimation of the organic carbon content.

LOI preparation and measurements were all executed according to described protocol by Heiri et al. (2001) in the sedimentology lab (Dep. of Geology, Ghent University). For all samples, approximately 1 g of freeze-dried material was placed in a preweighed porcelain crucible. These were then dried for 24 hours at 105 °C in the muffle furnace and placed in a desiccator for roughly 20-30 minutes to cool down without reabsorbing any air moisture by hygroscopic clays in the sediment material. The weight of the samples was then accurately measured before all samples were heated to 550 °C for 4 hours. Subsequently, the samples were again placed in a desiccator and re-weighed. The weight loss associated to the oxidation of organic matter is closely related to the organic content in the sample

(e.g. Dean, 1974; Bengtsson and Enell, 1986). LOI550 is then calculated using the following equation:

(퐷푊105−퐷푊550) 퐿푂퐼550 = × 100 퐷푊105

퐷푊105 = 푑푟푦 푠푎푚푝푙푒 푤푒𝑖푔ℎ푡 푏푒푓표푟푒 푐표푚푏푢푠푡𝑖표푛 (푔) 퐷푊550 = 푑푟푦 푠푎푚푝푙푒 푤푒𝑖푔ℎ푡 푎푓푡푒푟 ℎ푒푎푡𝑖푛푔 푡표 550°퐶 (푔)

The value for LOI550 gives then the percentage of dry weight loss at 550°C, which is an accurate estimate of the weight percentage of organic matter in the sample. A list of the LOI results can be found in the Appendix section.

4.4 CARBON AND NITROGEN ELEMENTAL AND ISOTOPIC ANALYSIS

4.7.1 SAMPLE PREPARATION

Prior to sample preparation for organic carbon and nitrogen isotope analysis, the total organic carbon (TOC) was estimated in order to conduct a qualitative measurement. The ideal amount of

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TOC for analysis lies between 0.8 and 1 mg. Previous studies in south-central Chile compared LOI550 and TOC values on similar soil samples and demonstrated the non-linear relationship between these values (Bartels, 2012; Paesbrugge, 2013). However, TOC weight percentages are about half of the

LOI550 weight percentages, if the latter has an organic matter content above 4 %. LOI550 values below 4 %, on the other hand, are in general not directly related to TOC. Nearly all samples used in this study exceeded the 4 % organic material. An empiric formula relating TOC and LOI550 was established based on sample measurements of Bartels (2012) and Paesbrugge (2013), as stated below:

푇푂퐶 (%) = 0.0097 × 퐿푂퐼550² + 0.1824 × 퐿푂퐼550 − 0.6822 푅2 = 0.9677

With the TOC content known for each sample, as calculated from LOI550, the ideal sample weight could be determined in order to achieve a TOC content of 0.8 to 1 mg, where the average of both was taken as target weight. Silver capsules (5x9 mm) were then filled with approximately the target weight of freeze-died sample material. The final weight could differ up to 10 % of the target weight in order to maintain a qualitative measurement. A list of the calculated TOC values, target weights and final weights can be found in the Appendix section. Because of the limitations of the elemental analyser (interfaced to a continuous flow isotope ratio mass spectrometer; EA-IRMS) used for this analysis, the total sample weight is required to be < 75 mg, so complete combustion of the sample material can be achieved, and had to contain less than 12 mg of carbon, as the IRMS detection limit for carbon lies between 150 to 12,000 µg.

Once all capsules were balanced and arranged in 96-well trays, they were treated with 60 µl of deionized (DI) water to wet the sediment material and with 60 µl of sulphurous acid (5-6 %) to remove inorganic carbon in the form of carbonates, which may interfere with the measurement of organic 13C in soil material (Verardo et al., 1990). This acid treatment is also the reason why silver (Ag) capsules were used instead of the less expensive tin (Sn) capsules, as tin decomposes when exposed to acid. Following the acidification, the samples were placed under an infrared heating lamp overnight to improve complete reaction, so inorganic carbon, if present, was released as CO2. Capsules were then folded using tweezers to tiny balls, organized in new clean trays, sealed and sent for analysis to the UC Davis Stable Isotope Facility (SIF; U.S., California).

4.7.2 ANALYSIS AT UC DAVIS STABLE ISOTOPE FACILITY

The amount (µg) of carbon and nitrogen is determined by the EA-IRMS. By dividing these weights by the total measured sample weights, we can determine the TOC and TN (total nitrogen) values, and consequently the C/N ratio for each sample. Subsequently delta values of 13C and 15N were measured by continuous flow isotope ratio mass spectrometry (CF-IRMS; 20-20 SERCON mass spectrometer) after sample combustion to CO2 and N2 at 1000 °C in a reactor packed with copper oxide and lead chromate. Following combustion, oxides were removed in a reduction reactor (reduced copper at

650°C). The helium carrier then flows through a water trap (magnesium perchlorate). CO2 and N2 were separated using a SUPELCO Carbosieve G column adsorption trap before entering the IRMS. Before and after the sample peaks and preliminary δ15N (Air) and δ13C (V-PDB) values were calculated, isotope ratios of the samples were compared to the ratios of pure cylinder gases injected directly into the IRMS (Bertrand et al., 2010). The preliminary isotope values are then adjusted by

24 correcting the values for the entire sample series based on the known values of the included laboratory standards. These laboratory standards have been previously calibrated against NIST Standard Reference Materials (IAEA-N1, IAEA-N2, IAEA-N3, USGS-40, and USGS-41). The long term standard deviation is 0.2 ‰ for δ13C and 0.3 ‰ for δ15N (Stable Isotope Facility UCDavis, 2016).

4.8 GRAIN SIZE ANALYSIS

4.8.1 SAMPLE PREPARATION

The analyses were performed on the siliciclastic fraction at exactly the same sample intervals as for LOI and C/N with a Malvern Mastersizer 3000 laser-diffraction particle-size analyser (Malvern Instruments Limited, Malvern, UK). To isolate the terrigenous fraction, sample material was suspended in 10 ml DI water and boiled with excess H2O2 (35 %) until the reaction stopped in order to remove organic matter. Subsequently, 1 ml of HCl (10 %) was added to the solution and boiled for one minute to remove any carbonates present. One hundred ml glass beakers were then filled with DI water, put aside for approximately 7 hours, giving time for all suspended particles to deposit, and decanted. This cycle was then repeated in order to ensure that the pH of the final solution was close to neutral. To remove biogenic silica, the mixture was boiled with 1 ml NaOH (8 %) for ten minutes and the same procedure was followed to neutralize the pH of the final solution. As a final step before measuring, 1 ml sodium hexametaphosphate (2 %) was added to the mixture and boiled shortly to assure the complete disaggregation of the particles.

4.8.2 ANALYSIS WITH MALVERN MASTERSIZER

The principle behind laser diffraction analysis is based on Mie and Fraunhofer diffraction theory, which suggests that the intensity of light scattered by a particle is directly proportional to the particle size (Mudroch et al., 1997). The angle of the laser beam and the particle size are inversely proportional related to each other, i.e. the laser beam angle decreases as the particle size increases and vice versa (McCave et al., 1986). Analysis is accomplished by means of a red light source (He-Ne laser; 632.8 nm) and a blue light source of shorter wavelength (LED; 470 nm) for the smallest measureable grain sizes. Particle-size is then calculated by measuring the intensity of light scattered as the laser beam passes through the suspension. The Malvern Mastersizer 3000 used in the sedimentology lab (Dep. of Geology, Ghent University) can measure a particle size between 0.01- 3500 µm, with a manufacturer’s accuracy better than 0.6 % and precision better than 0.5 %. A laser obscuration around 10 % was the objective to obtain good quality data for this type of fraction (i.e. mostly clays). If laser obscuration would be significantly higher, measured data would be skewed due to multiple scattering. If too low, the signal-to-noise ratio would be too low to have a representative measurement.

Several test samples were first measured to determine the amount of sample needed for each turbidite in order to achieve an obscuration of ~ 10 %. Results showed that 50 mg of freeze dried sediment was sufficient for all cores, except for those of Lake Rupanco (RUP02BIS, RUP03TRIS and RUP04) where 75 mg was needed. For three samples, not enough sample material was present as a result of previous analyses (i.e. VI8 0.5-1.0, 35 mg; RUP03TRIS 10.5-11.0, 35 mg; RUP03TRIS 15.0- 15.5, 45 mg) and therefore might be a little skewed. The measurement settings used during these

25 analyses are described in Table 3. Mean grain sizes and sediment descriptions for each sample can be found in the Appendix section.

Table 3. Settings used during grain size analysis on Malvern Mastersizer 3000.

Particle type Non-spherical particle mode Yes Is Fraunhofer type No Material properties Refractive index 1.550 Absorption index 0.010 Particle density 1.5 g/cm³ Different optical properties in blue light No Dispersant properties Dispersant name Water Refractive index 1.330 Level sensor threshold 100.000 Measurement duration Background (red) 12.00 s Sample (red) 12.00 s Perform blue light measurement Yes Background (blue) 12.00 s Sample (blue) 12.00 s Assess light background stability No Measurement sequence Aliquots 1 Automatic number of measurements No Number of measurements 3 Delay between measurements 0.00 s Pre-measurement delay 0.00 s Measurement obscuration Auto start measurement No settings Obscuration low limit 10.00 % Obscuration high limit 20.00 % Enable obscuration filtering No Accessory control settings Accessory name Hydro MV Is accessory dry No Stirrer speed 2500 rpm Ultrasound percentage 10 % Manual tank fill No Degas after tank and cell fill No Sonicate to stability No Ultrasound mode Continuous (From measurement start) Clean sequence settings Clean sequence type Normal Sonicate during clean No Analysis settings Analysis model General purpose Single result mode No Number of killed inner detectors 0 Blue light detectors killed No Fine powder mode No Analysis sensitivity Normal Analysed as Mastersizer 3000E No Result settings Result range is limited Result Units Volume Extend Result No Result Emulation No Averaging Averaging enabled No

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5. RESULTS

In this section, results for LOI, TOC, C/N and grain size are elaborated in a section for each lake and their respective cores. Since δ13C data does not provide any useful information regarding the provenance of lacustrine turbidites (section 3.1.1; because delta values for all the aquatic organic matter and land plants using C3 carbon fixation lie in the same range), no closer look will be taken to this variable.

5.1 LAKE VILLARRICA

5.1.1 VI4

LOI

The 1960 SED encountered in core VI4 (T1) shows a relatively high LOI550 base value (Fig. 6), followed by a minor increase where a maximum value is reached (10.22 %). Subsequently, values decrease quickly towards the top (8.57 %), showing a similar result to those measured in hemipelagic sediments (avg. 8.41 %). The turbidite resulting from the 2010 event (T2) could not be analysed with the LOI method due to the lack of sufficient sample (approx. 1 g).

TOC & C/N T1 shows a TOC of 3.94 % before increasing slightly to a maximum of 4.11 %. Subsequently, a gradual decrease is observed towards the top (3.26 %). C/N atomic ratios display a similar pattern, where the ratio observed at the base (11.17) increases to a maximum (11.82), before decreasing topwards. Measurements for T2 give a TOC of 4.36 % at the base. TOC decreases slightly towards the top before eventually increasing to the highest observed value for this core (4.54 %). Measured C/N ratios present a similar pattern as TOC again. The base is marked by a ratio of 9.70 that decreases slightly halfway the turbidite (8.80), before increasing to a final ratio of 9.32 at the top. C/N ratios for T1 clearly show elevated values, while those of T2 are very similar to the ones observed in hemipelagic sediments (avg. 9.37).

Grain size Grain size analysis of T1 demonstrates a normal grading with a basal mean grain size of 13.65 µm, fining upward to a top mean grain size of 6.22 µm. The base exists of a trimodal, very poorly sorted sandy mud (very fine sandy, very coarse silt), transitioning into a polymodal, poorly sorted mud (very fine silt). T2 doesn’t really show any grading, but seems to have very similar mean grain sizes as those measured for hemipelagic “background” sediments, which is on average around 5.40 µm. Encountered sediments can be classified as a trimodal or polymodal, poorly sorted mud (very fine silt), where the top is slightly coarse skewed.

5.1.2 VI8

LOI

In core VI8, the turbidite attributed to the 1960 earthquake (T1) shows a LOI550 value of 8.91 % at its base, relatively similar to the hemipelagic sedimentation (avg. 9.25 %). This is followed by a sudden

27 drop (6.70 %) and rise (10.60 %), after which values remain more or less stable throughout the turbidite upon decreasing again at the top (8.53 %). The similarity between the LOI550 value at the base and the one from the hemipelagic sediment together with the subsequent drop might suggest that the lower boundary of the turbidite was not sampled precisely enough and some hemipelagic “background” got included, since the general trend for nearly all turbidite sequences in this study shows the lowest LOI550 value at the base. The turbidite attributed to the 2010 event (T2) could not be analysed due to the limited amount of available sample.

TOC & C/N T1 commences with a TOC value of 3.19 %, nearly identical to the values observed in the hemipelagic sediments (avg. 3.19 %), before dropping to its lowest value of 1.98 %. This represents the assumed artefact as discussed for LOI550 (previous paragraph). The base is followed by a rapid increase to its maximal TOC value (5.99 %), upon decreasing to an average value around 4.7 %, where it remains relatively stable at for a few centimetres (12 to 14 cm). The top of the turbidite then decreases further to a TOC value of 4.04 %, following the general trend. The C/N ratio displays a base value of 9.84, from where it increases to its maximum (14.93). This maximum is followed by a decrease towards a C/N ratio of 12.15, shortly interrupted by a small peak (12.93) near the top. Compared to the hemipelagic sediments (avg. 9.56), all C/N ratios taken in the 1960 turbidite deposit are elevated. T2 on the other hand gives its highest TOC value at its base (4.22 %), before subsequently showing a subtly decrease to 3.82 % TOC. Hemipelagic “background” sediments average out on a TOC value of 3.20 %. C/N ratios for this turbidite present a similar decreasing path, with the highest ratio at the base (8.55) and lowest one at the top (8.21), comparable to the ratios observed in the hemipelagic sediments (avg. 8.61).

Grain size Analysis of T1 displays a mean grain size of 11.45 µm at the base, before promptly increasing to 23.03 µm and continuing in a normal graded sequence, fining upward to a mean grain size of 5.50 µm at the top. This confirms the assumption made in the previous sections paragraphs, i.e. that the base of the turbidite was not sampled precisely enough and some hemipelagic “background” got included. The top of the event deposit has a similar mean grain size as the ones measured for the hemipelagic samples (avg. 5.13 µm). The “real” lower boundary of the turbidite (15.0 to 15.5 cm) exists of a polymodal, poorly sorted sandy mud (very fine sandy, very coarse silt), gradually fining up in the event to a polymodal, poorly sorted mud (fine silt). A small peak (7.07 µm) can be seen near the top, coinciding with the small peak also observed for C/N. T2 doesn’t really show any grading, but rather mean grain sizes equivalent to the hemipelagic sediments, and can be classified as a mud existing of fine to very fine silt.

5.1.3 VI18

LOI

The turbidite in core VI18 shows the lowest LOI550 value at the base (3.49 %), whereupon an increase is observed (7.89 %) that remains relatively stable between 3 to 5 cm core depth. This is followed by a small decrease in LOI550, with values ranging between 6.16 % to 6.72 % up till 0.5 cm of the top, where a sudden increase is noted to 7.88 %. All LOI550 measurements from turbidite samples have a lower value than those taken in the hemipelagic sediments (avg. 9.74 %).

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TOC & C/N The SED exhibits the lowest TOC value at its base (1.29 %) followed by a prompt increase towards its maximum value of 3.25 %. This increase is then followed by a decrease in TOC that remains relatively stable at around 2.6 %, besides some minor fluctuations, upon suddenly increasing at the top of the sequence to 3.01 %. Average TOC for hemipelagic sediments (3.41 %) are higher in comparison to all measured turbidite samples for this core. C/N results show some fluctuations around a ratio of 11 in the lower half of the turbidite (2.5 to 5.5 cm), before suddenly increasing significantly to a maximum ratio of 13.89. The point at which this abrupt increase is observed, coincides with a sharp colour change in the core from lighter to darker sediments. The peak is then followed by a rapid decrease towards the lowest measured ratio for this deposit (9.32). Compared to C/N ratios observed in the hemipelagic sediments (avg. 9.89), the upper half of the SED obviously shows some elevated C/N ratios, while in the lower half this contrast is less outspoken, though still clearly visible.

Grain size Mean grain sizes measured for the SED in core VI18 show a coarse base (33.02 µm) fining upward to a first minimum of 9.39 µm. This is followed by a rapid transition towards a next maximum in mean grain size (15.92 µm), coincident with the abrupt colour change in the core, before fining upward again to a second minimum of 7.20 µm, similar to the observed mean grain size for the hemipelagic sediment (avg. 7.32 µm). This sequence clearly shows two normal graded sequences on top of each other. The base of the event deposit is marked by a bimodal, poorly sorted sandy mud (very fine sandy, very coarse silt) developing to a trimodal, poorly sorted mud (medium silt) at the first minimum. A transition to a trimodal, poorly sorted mud (coarse silt) is then noted at the next observed maximum, gradually changing to a polymodal, very poorly sorted sandy mud (fine sandy, very fine silt) at the top.

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Fig. 6. Results for the LOI550 measurements, the carbon and nitrogen isotopic analyses and the grain size analyses for the cores VI4, VI8 and VI18. Artefact: VI4, mean grain size data point in the interval 19 to 20 cm was lost.

5.2 LAKE CALAFQUÉN

5.2.1 CGC1

LOI In core CGC1, a part of the SED could not be measured due to insufficient coring depth. The part that was cored shows the top of the turbidite deposit also encountered in core CB4, since they are in close proximity to one another (Fig. 4; Van Daele et al., 2015). The base of the core has a LOI550 value of 2.43 % and decreases further to values between 1.24 % to 1.72 % (Fig. 7), which is very low compared to the hemipelagic “background” sediments (avg. 8.48 %).

TOC & C/N The event in core CGC1 has the lowest measured TOC values throughout this whole study. TOC values show no trend and fluctuate in minor quantities between the values 0.29 and 0.45 %, which is significantly lower than the hemipelagic “background” (avg. 2.77 %). C/N atomic ratios on the other hand do display some trend. The base of the core marks an elevated C/N ratio of 14.04 compared to the hemipelagic sediment (avg. 10.89), and is followed by a gradual decrease towards the top (11.64). This gradual decreasing trend is shortly interrupted by a sudden trough (11.0) between 24.1 and 24.6 cm downcore.

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Grain size The SED contains very coarse material throughout its whole sequence, compared to the hemipelagic sediments (avg. 9.62 µm). Analysis of the base shows a mean grain size of 64.57 µm, which gradually decreases towards the top, where a mean grain size of 39.36 µm is measured. A small trough can be observed in the interval 23.6 to 24.1 cm, coincident with the one observed for C/N. The base is determined as a unimodal, poorly sorted muddy sand (very coarse silty, very fine sand) and shifts towards the top to a unimodal, poorly sorted sandy mud (very fine sandy, very coarse silt).

5.2.2 CB4

LOI

Core CB4 shows the missing lower part of core CGC1. LOI550 measurements in CB4 demonstrate the general trend, i.e. a low base value (5.41 %) with subsequent significant increase (9.75 %), shortly followed by a decrease towards the top (4.76 %). The maximum LOI550 value measured in the turbidite event (9.75 %) is similar to the value observed in the hemipelagic sediments (avg. 9.58 %).

TOC & C/N The base of is marked by a low TOC value (1.89 %), followed by an increase towards its maximum value (4.08 %). After reaching this maximum, a rapid decrease transitioning into a more gradual one can be noted, eventually reaching its minimum value of 1.45 %. The hemipelagic samples are characterised by an average TOC content of 3.08 %, thus exceeding nearly all of the measured values throughout the turbidite, with exception of CB4 19.3-19.8 and CB4 19.8-20.3. C/N ratios present a similar pattern as the one observed for TOC. The base of the turbidite shows a relatively lower ratio of 12.30, which increases to a maximum of 17.03 in the same depth interval as for the observed TOC peak (i.e. 19.3 to 19.8 cm downcore). This is followed by a decrease towards ratios around 12 with some minor fluctuations, upon eventually decreasing to a minimum of 10.82, comparable to the C/N ratios observed in hemipelagic sediment (avg. 10.21).

Grain size A normal graded SED is shown with a basal mean grain size of 49.62 µm, fining upwards to a top mean grain size of 4.71 µm, which is significantly lower than grain sizes measured for hemipelagic sediments (avg. 7.66 µm). Some minor fluctuations are noted in between the top and base, but are of no significance. Encountered sediments at the base can be classified as polymodal, very poorly sorted muddy sand (very coarse silty, very fine sand) that transitions to unimodal, poorly sorted mud (fine silt) towards the top.

5.2.3 CB9

LOI

The event deposit in core CB9 displays a comparable LOI550 path. A low base (3.19 %) is followed by a gradual increase to values around 6.5 %, where it remains stable for about 4 cm (27.9 to 31.9 cm), upon decreasing and reaching a new stable value around 5.1 % (19.9 to 26.9 cm). Only the very top of the turbidite shows another decrease towards 3.85 %. All turbidite samples have a lower measured LOI550 value in comparison to the hemipelagic sediments (avg. 7.13 %).

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TOC & C/N The TOC values from the turbidite samples show a stepwise increase to a maximum value of 2.29 %, starting from the typical lower base (0.83 %). After reaching a maximum, TOC gradually decreases to a next minimum (1.41 %), which coincides with a sharp colour change in the core, before increasing again to a value around 1.6 %. Subsequent to this relatively steady interval (21.9 to 25.9 cm), a gradual decrease to 0.93 % TOC is observed towards the top. Measurements on hemipelagic sediments gave a mean TOC of 2.64 %, exceeding all turbidite samples. C/N ratios show an increase to a first maximum of 11.07 (32.9 to 33.9 cm), before decreasing gradually towards the observed colour change with measured ratios as low as 8.94. The first sample taken in this upper darker half of the turbidite displays a sudden increase in C/N ratio, with maximum ratios reaching 10.92, upon decreasing in a stepwise manner towards the top (8.18). Roughly two peaks are observed, separated by a wide trough. The C/N ratios measured in these two peaks clearly indicate elevated values in comparison to the observed hemipelagic “background” sediment (avg. 9.37).

Grain size Analysis of the SED displays a coarse base with a mean grain size of 55.40 µm, gradually fining upwards to a first minimum of 8.47 µm, similar to mean grain sizes observed for hemipelagic sediments (avg. 8.58 µm). This minimum is followed by a rather sudden rise in grain size to a second maximum of 18.32 µm, before gradually decreasing again to the lowest measured grain size for this event deposit (6.14 µm). The rise in grain size occurs simultaneously with a change in colour from lighter to darker sediments. Again, two normal graded sequences seem to be stacked above each other, as was also the case for core VI18. The lower boundary is marked by a trimodal, poorly sorted muddy sand (very coarse silty, very fine sand) that gradually changes into a polymodal, poorly sorted mud (fine silt) near the first minimum. Subsequently, a deposition of polymodal, very poorly sorted sandy mud (fine sandy, coarse silt) is determined at the base of the upper, darker part of the SED, which slowly transitions into a bimodal, poorly sorted mud (very fine silt) near the top.

5.2.4 CALA05

LOI Core CALA05 contains both SEDs triggered by the 1960 and 2010 earthquakes. The one attributed to the 1960 event (T1) features a low LOI550 base value (6.43 %), succeeded by an increase to 8.66 % with some minor variations throughout the turbidite, relatively similar to the hemipelagic “background” (avg. 8.99 %). A dissimilarity with the general trend though, is a sudden increase in

LOI550 at the very top of the turbidite(9.34 %). The 2010 event deposit (T2) doesn’t really show any kind of trend since only few samples could be measured due to limited amount of available sediments. LOI550 measurements gave values of 11.64 % for the base and 10.98 % for the top, which is slightly higher than those observed in the hemipelagic sediments (avg. 10.54 %).

TOC & C/N TOC results for T1 present a low basal value of 1.93 %, abruptly increasing to a first maximum of 3.00 %. A subsequent gradual decrease is observed towards a TOC of 2.71 % before spiking to a value of 4.00 %. C/N displays a different pattern. Measured values roughly fluctuate between ratios of 8 and 9, where the spikes show a decreasing trend towards the top of the turbidite. For T2, TOC remains relatively stable around 3.4 %. C/N results for this deposit are very low. The base is marked by a ratio

32 of 6.11, which somewhat increases toward the top (7.07). TOC for hemipelagic sediments is determined at an average of 2.90, which does not differ so much for both measured turbidites, besides the base and top value for T1. C/N ratios for these “background” sediments (avg. 7.89) indicate elevated levels for the 1960 event in some degree, but hardly of significance.

Grain size Measurements for T1 display a coarse base with a mean grain size of 31.81 µm that abruptly decreases to 10.86 µm, from where a gradual decline in grain size can be noted towards a mean grain size of 4.08 µm at the top. The base is marked by a polymodal, very poorly sorted sandy mud (very fine sandy, very coarse silt), which develops towards a trimodal, very poorly sorted mud (very fine silt) near the top. T1 thus shows a normal grading, in contrary to T2, which doesn’t show any clear grading due to the lack of samples. The latter seems to have very similar mean grain sizes as the ones observed for hemipelagic samples (avg. 5.11 µm) and an identical sediment texture, which is a poorly to very poorly sorted mud (very fine silt).

5.2.5 CALA08

LOI In core CALA08, the observed turbidite shows the lowest value at the base (5.63 %), followed by an increase (6.72 %) with subsequent drop (5.92 %), before gradually increasing again to values around 7.3 % for the next couple of centimetres (4.5 to 8.5 cm). This steady depth range is then succeeded by a slow decrease towards the top (6.32 %). Hemipelagic sediments are characterised by a relatively high LOI550 value (avg. 10.05 %), exceeding all measured turbidite samples.

TOC & C/N Elemental analysis presents the general trend for TOC. The lowest value is found at the base (1.71 %) and is followed by an increase towards a maximum value of 2.58 %, before gradually decreasing in the direction of the top (2.06 %). All turbidite samples have a lower TOC compared to the ones observed in the hemipelagic sediments (avg. 3.01 %). C/N shows a gradual increase with ratios going from 11.42 to 12.65, before decreasing near the top to 11.52. Background measurements in hemipelagic sediments give an average C/N ratio of 8.05, pointing to elevated C/N levels in the observed SED.

Grain size Mean grain sizes demonstrate a gradual decrease from a coarse base (24.17 µm) towards a first minimum (11.24 µm), from where a subtle increase can be noticed towards a mean grain size of 12.11 µm, before the final decline towards the top (8.83 µm) commences. The lower boundary can be described as a unimodal, poorly sorted sandy mud (very fine sandy, very coarse silt) with a transition towards the top to a trimodal, poorly sorted mud (medium silt). Hemipelagic “background” sediments show an average mean grain size of 5.88 µm and can be classified as unimodal, poorly sorted mud (fine silt).

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Fig. 7. Results for the LOI550 measurements, the carbon and nitrogen isotopic analyses and the grain size analyses for the cores CGC1, CB4, CB9, CALA05 and CALA08.

5.3 LAKE RIÑIHUE

5.3.1 RI5

LOI

LOI550 measurements for the event in core RI5 present a lower base value (10.47 %), followed by an increase towards its maximum (12.42 %; Fig. 8). This maximum is followed by a gradual decrease with some minor fluctuations near the top, showing a similar LOI550 signature as the measured hemipelagic “background” sediments (9.15 %).

TOC & C/N TOC levels for the show a gradual increase with respect to the base from 4.25 % to a maximum of 5.32 %. This is shortly followed by a sudden decrease towards 3.90 % TOC at the interval between 12.5 to 13.0 cm, coinciding with the observed colour change in the core. Subsequently TOC gradually decreases further towards the lowest measured value for this event (3.36 %), before increasing again at the top (3.77 %) to values similar to those measured in hemipelagic sediments (avg. 3.91 %). C/N results show a nearly identical pattern as the one observed for TOC. A rise in C/N ratios is noted relative to the base (12.02) towards a maximum of 14.60, before a sudden drop to 11.60 is observed near the colour change. From here on, a gradual decrease commences to a minimum of 10.59, upon spiking to a C/N ratio of 11.90 at the top of the turbidite. An average ratio of 10.78 was measured for the hemipelagic sediments, clearly suggesting elevated levels for the lower (darker) part of the event deposit and ratios somewhat similar to the “background” for the upper (lighter) part.

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Grain size The SED displays a mean grains-size of 15.21 µm at the base, which increases towards a first maximum of 23.41 µm, before decreasing towards the observed colour change in the core to a mean grain size of 18.79 µm. Around this colour change from darker to lighter sediments, an increase in mean grain size is noted towards a second maximum of 23.75 µm. From here on, measurements show a decrease towards the top, reaching a second minimum at 6.58 µm in the interval 8.5 to 9.0 cm, before subtly increasing again at the very top (8.37 µm). The observed minimum shows a similar mean grain size as the ones observed for hemipelagic samples (avg. 6.71). The lower part of the SED exists of a polymodal, very poorly sorted sandy mud (very fine sandy, very coarse silt), which develops into a polymodal, poorly sorted mud (very fine silt) near the second minimum.

5.3.2 RI7

LOI

The 1960 SED in core RI7 (T1) displays a lower LOI550 value for the base (7.39 %) with subsequent abrupt increase to its maximum value (13.65 %). A subsequent gradual decrease is observed towards 11.96 %, after which a small gradual increase can be noted towards the top (12.84 %). The 2010 SED (T2) shows its lowest value also at the base (7.84 %) before increasing rapidly towards its highest value of 16.99 %. This rapid increase is followed by a more gradual decrease towards the top (14.26

%). LOI550 measurements on hemipelagic sediments give a mean value of 10.13 %, lying in between the observed minimum and maximum values of both turbidites.

TOC & C/N T1 shows fluctuating TOC levels between 4.3 and 5.6 % with no distinct trend visible. The troughs have a comparable TOC to those measured in hemipelagic sediments below the event (avg. 4.46 %).

C/N ratios on the other hand give an unmistakable pattern for intercalation of C3 plant derived material. Hemipelagic sediments gave an average ratio of 10.81, while the base of the SED already gives a ratio of 20.25, rising even further to the highest value observed in this study (26.13). This is followed by a rather rapid decrease towards the top, reaching a minimum at 14.96, before slightly increasing to 15.71 in the uppermost turbidite sample. TOC measurements for the T2 display the lowest value at the base (3.64 %), followed by an increase to its highest value (8.25 %) and subsequent decreasing towards the top (6.23 %). C/N shows a similar pattern, where a lower base (11.32) is followed by an increase to its maximum (16.54), before gradually decreasing near the top (13.84). Also this event clearly shows an elevation in C/N ratio compared to hemipelagic sedimentation (10.81).

Grain size Grain size measurements for the T1 show a coarse base, coarsening up further to a maximum mean grain size of 64.40 µm. A subsequent decrease towards the top can be noted, reaching a minimum in 23.36 µm before suddenly increasing again at the very top to a mean grain size of 27.67 µm. The base of the event exists of a unimodal, poorly sorted muddy sand (very coarse silty, very fine sand) transitioning into a unimodal, poorly sorted sandy mud (very fine sandy, very coarse silt) near the top. T2 also displays a normal graded sequence. The maximum mean grain size is reached subsequent to the basal sample, giving a value of 50.35 µm. This maximum is followed by a gradual decrease towards the top and reaches a minimum at a mean grain size of 19.76 µm. The sample

36 taken at the absolute top of the event deposit (0.0 to 0.5 cm) displays a sudden increase, with a mean grain size of 25.26 µm. All measured grain sizes for both SEDs display significantly coarser material throughout the whole deposit, compared to those observed in hemipelagic samples (avg. 9.23 µm). Sediments encountered in T2 can be described as a uni- to polymodal, very poorly sorted sandy mud (very fine sandy, very coarse silt).

5.3.3 RI8

LOI

Measurements for the SED in core RI8 display a lower LOI550 value at the base (9.08 %), immediately followed by a spiking increase (11.68 %) and subsequent decrease towards 8.73 %, before increasing again to values around 9.4 % throughout the remaining part of the turbidite. LOI550 values of the measured hemipelagic samples show a relatively wide range to be a representative “background” measurement (6.04 % and 10.25 %).

TOC & C/N TOC levels at the base of the SED (2.67 %) rapidly rise to a maximum (5.33 %), followed by a gradual decrease towards 3.32 %. TOC then shortly rises to 3.44 %, before displaying a final decrease at the top (3.15 %). C/N measurements on the other hand immediately show a maximum at the base of the event (17.07) that gradually decreases to a minimum (10.24). The small hump noted in the TOC pattern near the top is also observed for C/N. A short increase (10.60) is demonstrated subsequent to the C/N minimum, before eventually decreasing again at the top (10.25). The interval between 13.2 to 14.9 cm evidently gives elevated levels for C/N compared to the hemipelagic “background” (avg. 10.24), while those higher up the turbidite seem to give very similar measurements to those of the hemipelagic samples.

Grain size Analysis of the event deposit demonstrates a genuine normal graded succession. Mean grain sizes gradually decrease from a coarse base (73.46 µm) towards a very fine-grained top (6.70 µm), similar to the mean grain size measured for the hemipelagic samples (avg. 5.97 µm). The sediment texture for the base can be classified as a trimodal, poorly sorted muddy sand (very coarse silty, very fine sand). Towards the top of the event, sediments gradually transition into a trimodal, poorly sorted mud (very fine silt).

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Fig. 8. Results for the LOI550 measurements, the carbon and nitrogen isotopic analyses and the grain size analyses for the cores RI5, RI7 and RI8. Artefact: RI7, δ13C data point in the interval 16.5 to 17.5 cm was left out due to poor chromatography.

5.4 LAKE RUPANCO

5.4.1 RUP02BIS

LOI Core RUP02BIS contains a part of a megaturbidite (i.e. base was not cored; Van Daele et al., 2015).

LOI measurements show a very stable succession in the interval between 49.5 to 80.5 cm with LOI550 values increasing very subtly and gradually from 16.29 % towards 17.20 % (Fig. 9). Subsequently, a steadily decrease is noted between 49.5 and 34.5 cm towards 13.41 %, followed by an increase, stabilising at about 15.05 % (24.5 to 30.5 cm) upon decreasing again towards the top of the megaturbidite to 10.50 %. The hemipelagic sediments show a stable, seemingly fixed LOI550 value at about 8.68 %, clearly being a lower signature than any measurement taken in the event deposit.

TOC & C/N Measured TOC displays a very consistent trend between 24.5 to 80.5 cm, only with some minor variations around a mean TOC of 5.87 %. After this stable interval, a rather quick decrease is noted somewhere between 19.5 and 24.5 cm towards 3.77 % TOC, which slightly decreases further near the top to 3.69 %. These lower values at the top are relatively similar to the ones observed in hemipelagic sediments (avg. 3.41 %). C/N results also give a very stable pattern with a mean value of

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15.47 and minimum and maximum value of 14.55 and 16.04, respectively. Ratios for hemipelagic sediments (avg. 12.24) point to elevated levels for the whole megaturbidite.

Grain size The megaturbidite encountered in core RUP02BIS represents very steady mean grain sizes, ranging around 8 to 10 µm for most part of the event deposit (25 to 81 cm), justifying the alternative term “homogenite”. This steady interval is subsequently interrupted by a relatively small spike (12.19 µm), before decreasing to the lowest mean grain size for this event (6.86 µm). In general, nearly all measured mean grain sizes throughout this deposit are similar to the ones observed in hemipelagic samples (avg. 9.89 µm). Sediments for the entire megaturbidite can be described as bimodal, poorly sorted mud (medium silt). The data from the observed small spike and subsequent drop differs from the megaturbidite in being trimodal and evolving into a finer sediment fraction (fine silt).

5.4.2 RUP03TRIS

LOI

The SED observed in core RUP03TRIS shows no distinct trend. LOI550 measurements throughout the turbidite are characterized by values variating around 8.56 ± 0.82 %. Hemipelagic samples display a wide variation in LOI550 “background” value, ranging from a similar signature as seen in the turbidite deposit (8.16 %) to a value as low as 4.87 %.

TOC & C/N The base of the event deposit is marked by 3.30 % TOC. This is followed by a decrease, remaining relatively stable around 2.95 %, before increasing to a maximum observed value of 3.37 % for this deposit. A subsequent rapid decrease (2.92 %) and increase (3.20 %) follows this maximum, before eventually displaying a final decrease towards the top. Hemipelagic sediments show a wide range for

TOC (similar to the case for LOI550), being either similar to the values observed in the turbidite (2.87 %) or considerably lower (1.67 %). C/N measurements give a rather stable pattern with a mean ratio of 9.79 (excluding peak values). Two peaks can be distinguished with a ratio of 11.22 and 10.44. Compared to measurements in hemipelagic sediments (avg. 9.13), no significant difference can be observed besides the two observed peaks.

Grain size Mean grain sizes display a very subtle fining upwards succession. This fining upward trend is shortly interrupted by a small peak between 10.5 and 11.0 cm, which may be due to the lack of sufficient sediment during analysis (only 35 mg of sample was available for this interval, instead of the calculated 75 mg). A mean grain size of 10.67 µm was determined for the base, which is followed by a gradual decrease towards a mean grain size between 7 and 8 µm for the upper part of the event deposit (5.5 to 10 cm). Sediments at the base exist of a trimodal, poorly sorted mud (medium silt) transitioning to a more fine-grained bimodal, poorly sorted mud (fine silt). Observed grain sizes for the SED seem very similar to the hemipelagic “background” sample taken in the interval between 17.0 to 18.0 cm. The hemipelagic sample taken between 18.0 to 19.0 cm on the other hand gives a mean grain size significantly higher than any other measured value for this core (27.64 µm), which may suggest that it is not representative for the regular steady state sedimentation.

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5.4.3 RUP04

LOI

The turbidite deposit in core RUP04 demonstrates the general observed trend. The lowest LOI550 value is found at the base of the event deposit (8.96 %). This is followed by a significant increase, almost twice as large as the value measured at the base (16.78 %), before dropping to 15.36 %. Subsequently, the values increase again step by step, reaching a maximum at 18.21 %, before decreasing towards the top (16.59 %). All turbidite samples, with exception of the base, exceed measured hemipelagic values (avg. 12.93 %).

TOC & C/N TOC for the SED in core RUP04 shows the lowest value at its base (3.36 %) from where an increase is observed to a first peak value of 7.45 %. This is followed by a trough with a minimum of 5.72 % TOC, before gradually increasing again to the highest observed value for this deposit (8.28 %). A subsequent decrease is noted with a sudden rise at the very top (8.23 %). All measured TOC values for the turbidite, with exception of the base, exceed the ones observed in hemipelagic samples (avg. 5.40 %). The general pattern for C/N ratios depicts a rise throughout the whole event deposit, with some minor fluctuations in between. The base gives a ratio of 14.15, and increases towards the top where a C/N ratio of 16.66 is determined. Two somewhat peaking values in this trend are observed, marked by a ratio of 16.89 and 17.12. Measurements on hemipelagic sediments (avg. 12.02) indicate elevated values for the whole turbidite.

Grain size Grain size distribution displays a coarse base with a mean value of 30.41 µm, gradually decreasing towards a first minimum of 21.07 µm. This minimum is followed by a sudden rise to a second maximum mean grain size of 25.65 µm, before gradually fining upward again. A second minimum (17.81 µm) is reached between 11.3 to 12.3 cm, which is followed by a stepwise increase to a third maximum with a mean grain size of 19.55 µm, before commencing its final decrease towards the top (15.59 µm). All measured grain sizes throughout the event clearly seem higher than the ones observed for regular sedimentation in hemipelagic samples (10.86 µm). The coarse sediments at the base can be classified as unimodal, poorly sorted sandy mud (very fine sandy, very coarse silt). Towards the top, episodically more medium to coarse silt gets incorporated in the deposit, with eventually a bimodal, poorly sorted mud (medium silt) at the very top.

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Fig. 9. Results for the LOI550 measurements, the carbon and nitrogen isotopic analyses and the grain size analyses for the cores RUP02BIS, RUP03TRIS and RUP04.

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6. DISCUSSION

6.1 CORRELATION BETWEEN LOI550 AND TOC

As mentioned in the methods section (section 4.3), the weight loss associated to the oxidation of organic matter during LOI analysis, is closely related to the organic content in the sample (e.g. Dean,

1974; Bengtsson and Enell, 1986). When comparing the LOI550 data with the TOC percentages determined by the UC Davis SIF, all cases with exception of the events observed in core CALA05 show a strong to very strong positive linear correlation (Table 4).

Table 4. Correlation between LOI550 and TOC values. Pearson correlation coefficient interpretation: 0.1 < |R| < 0.3 is a weak correlation; 0.3 < |R| < 0.5 is a moderate correlation; 0.5 < |R| < 1 is a strong correlation; |R| = 1 is a perfect correlation (Cohen, 1988).

Core Pearson correlation Number of samples coefficient (R) (n) VI4 0.97 8 VI8 0.86 13 VI18 0.93 13 CGC1 0.99 10 CB4 0.85 15 CB9 0.82 19 CALA05 0.50 15 CALA08 0.93 14 RI5 0.90 18 RI7 0.75 17 RI8 0.84 14 RUP02BIS 0.97 16 RUP03TRIS 0.74 19 RUP04 0.93 15

In general, TOC weight percentages are about half of the LOI550 weight percentages when sample material contains more than 4% organic matter. In this study, estimations of TOC were calculated, using the empiric formula obtained by Bartels (2012) and Paesbrugge (2013). Nearly all samples exceeded this threshold, with the exception of the ones taken in core CGC1 (LOI550 values around

1.50 to 2.50 %) and a few other individual samples. When plotting the LOI550 percentages with the TOC content, a similar relationship can be observed as demonstrated by the experimental formula from Bartels (2012) and Paesbrugge (2013). Though, TOC values seem to be slightly underestimated. The formula from Bartels (2013) and Paesbrugge (2012) was derived on the basis of 14 samples, while for this study 206 measurements where used. To estimate the relationship between LOI550 and TOC for this dataset, a linear regression was applied for the sediment samples. The linear trend is then described by the formula:

푇푂퐶 (%) = 0.4418 × 퐿푂퐼550 − 0.5524 푅² = 0.8939

The determination coefficient (R²) indicates that this model explains about 89.4 % of the variability of calculated TOC values, which is statistically a very good fit. The slope (m = 0.4418) implies that about 44 % of the organic material consists of carbon. The x-intercept of approximately 1.25 % suggests that other reactions beside the burning of organic matter take place at 550 °C. A reaction that may

43 contribute to the observed weight loss is continued dehydration of some clay minerals, since some types of clay minerals still lose constituent water at temperatures higher than 105 °C (Murray and White, 1955). Another potential reaction responsible for weight loss is the oxidation of metals in the sample material. When fitting the dataset with a second degree polynomial function, a nearly identical coefficient of determination is achieved (R² = 0.895). A power function on the other hand shows a significant higher coefficient of determination (R² = 0.936), demonstrating the non-linear relationship between TOC and LOI550 as described by Bartels (2012) and Paesbrugge (2013). The observed values are thus best predicted by a power regression model:

1.218 푇푂퐶 (%) = 0.2287 × 퐿푂퐼550 푅² = 0.9355

Something worth noting is that the relationship between TOC and LOI550 displays a seemingly higher variability for samples with a relatively high content of organic material (LOI550 > 10 %). A possible reason explaining these fluctuations is the difference in TOC content between organic matter from an algal origin and organic matter from woody plants. For example, diatom organic matter typically has a mean overall TOC content of 25 %, while for wood TOC varies between 35 to 65 % (Hedges, 1975; Walsh, 1983). This dissimilarity results due to the presence of lignin in wood, which contains about 50 % more carbon than cellulose (Benner et al., 1987). Therefore, in an oxic facies (e.g. studied lakes) TOC content is often determined by variations in absolute phytoclast abundance (Tyson, 1995).

Nevertheless, LOI550 can be considered as a very useful tool to estimate TOC in samples on a local scale and to optimise the amount of sediment needed for elemental and isotopic analyses of solid materials.

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Fig. 10. Relationship between TOC and LOI550 results for cores VI4, VI8, VI18, CGC1, CB4, CB9, CALA05, CALA08, RI5, RI7, RI8, RUP02BIS, RUP03TRIS and RUP04. Linear, polynomial (2nd degree) and power regression models for observed dataset compared with the polynomial (2nd degree) regression model of Bartels (2012) and Paesbrugge (2013).

6.2 RELATION BETWEEN C/N ATOMIC RATIO AND GRAIN SIZE

Pearson correlation coefficients were determined between xx and yy for the events in the studied cores, measuring the strength and direction of a potential linear relationship. Since it is mostly the amount of nitrogen that changes in the different types of organic matter and not carbon, C/N values were inverted (N/C) to achieve a more linear relationship (Perdue and Koprivnjak, 2007). No consistent relationship between particle sizes and N/C ratios is present. A high variability in coefficients is observed, with values mostly indicating weak negative linear trends (Table 5). Only for the events in core VI4, CGC1, RI5, RI7 and RI8 there is a significant negative relationship between the sediment mean grain size and the N/C ratios (p < 0.05).

Table 5. Correlation between grain size and N/C values. Pearson correlation coefficient interpretation: 0.1 < |R| < 0.3 is a weak correlation; 0.3 < |R| < 0.5 is a moderate correlation; 0.5 < |R| < 1 is a strong correlation; |R| = 1 is a perfect correlation (Cohen, 1988).

Core Pearson correlation p-value Number of samples coefficient (R) (n) VI4 -0.78 0.0074 10 VI8 -0.15 0.59 16 VI18 -0.32 0.28 13 CGC1 -0.70 0.035 9 CB4 0.23 0.35 14 CB9 -0.28 0.25 19 CALA05 -0.37 0.17 15 CALA08 -0.50 0.071 14 RI5 -0.88 1.2E-6 18 RI7 -0.83 3.4E-5 17 RI8 -0.95 4.1E-7 13 RUP02BIS 0.16 0.55 16 RUP03TRIS 0.39 0.10 19 RUP04 -0.50 0.059 15

N/C ratios and grain sizes are plotted in Figure 11. Only the SEDs originating from Lake Riñihue show a consistent strong negative relationship between both quantities (R < -0.83). Here the coarsest fraction coincides with the lowest measured N/C ratios (highest C/N ratios) and vice versa. This could somewhat be expected, since in these coarse intervals macroscopic leaf and wood fragments were found during sampling. The megaturbidite in core RUP02BIS shows a very weak positive linear relationship according to the statistics (R = 0.16). In this case the correlation coefficient is misleading due to minor variations around a relatively stable mean grain size and N/C ratio. The events in core VI4 seemingly give a strong negative correlation, but this might be due to the limited amount of samples for both events. The upper dark LT2 part of the event in core VI18 (R = -0.99) and the event in core CGC1 also show a strong correlation, where the coarser fraction coincides with the lower N/C ratios (or higher C/N ratios) and vice versa. However, in all other studied SEDs peaks and troughs

45 between both variables do not match and no consistent relation can be observed. Though, based on the scatter plot relating grain size and N/C atomic ratio, it is safe to assume that a relationship in general, if present, is negative and may show a relatively good linear correlation when land plant derived material got included in the turbidity current (LT2 types).

Something worth noting is that for the same grain size, N/C ratios for the events in Lake Calafquén are consistently higher than for those observed in Lake Riñihue (Fig. 11). An answer explaining this observation might be found in the lake morphology and coring locations (Fig. 4 and 5). In Lake Riñihue all coring locations are relatively near-shore since the lake has a lenticular, narrow shape. In Lake Calafquén on the other hand, most core locations are rather far away from any onshore sediment source.

The very low N/C values displayed by core RUP02BIS are also interesting. Only the fine-grained top of this turbidite was cored and despite these very fine-grained sediments, N/C ratios are very low. This clearly indicates an onshore source and suggests that N/C for this case is independent from the grain size. This is probably because the complete megaturbidite is originating from a source onshore, directly from slope failures.

Fig. 11. Relationship between mean grain size and N/C atomic ratio for cores VI4, VI8, VI18, CGC1, CB4, CB9, CALA05, CALA08, RI5, RI7, RI8, RUP02BIS, RUP03TRIS and RUP04.

Another interesting observation is that C/N peaks sometimes seem “delayed” in comparison with the coarsest fraction of the SEDs. A possible explanation for this is the difference in settling velocity between coarse grains and organic material (e.g. plant fragments), where the latter may move slower down the water column due to its shape, weight and buoyancy. Examples where such

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“delayed” C/N peak can be observed, are the events in core VI4 (1960 SED), VI8 (1960 SED), VI18 (lower light part), CB4, CB9, CALA05 (1960 SED) and RUP04 (Fig. 6, 7 and 9).

6.3 INTERPRETATION C/N ATOMIC RATIO AND GRAIN SIZE

C/N atomic ratios and δ13C-values represent the whole mixture of organic components and can be used to distinguish sources of organic matter in sediments. Three distinctive suites are relevant in a lacustrine environment (Fig. 3), of which one (C4 plants) can be excluded due to its limited presence in the nearby surrounding of the studied lakes, in contrary to the plants who follow a C3 carbon fixation pathway. Comparison of these elemental and carbon isotopic values result in data points between two endmembers, where organic matter originates from lacustrine algae on one side and from organic matter from C3 land plants on the other side. In most cases it will be a mixture between both. Therefore samples were also taken in hemipelagic “background” sediments, so an increased influence from land plant derived organic matter compared to regular sedimentation could be distinguished. δ13C-values range between -31.31‰ and -26.90‰, which is in agreement with the expected algal and C3 plants signature. In the case a SED is composed of reworked hemipelagic sediments, a similar signature will be observed as seen in the “background” samples for that event. If a trend towards the C3 plants suite is displayed, a source of land based plants is involved. Depending on the strength of this signal and reports from the 1960 and 2010 events, a more specific source area can be appointed (e.g. onshore landslide, delta failure, mudflow, etc.).

The classification of turbidites applied in the next sections is based on the one used in Van Daele et al. (2015), as discussed in section 3.2. Though, since in this study more information is obtained regarding the sedimentary organic matter, a few adaptations are added. Depending on the enrichment of organic matter originating from C3 land based vegetation, a distinction can be made between LT1 type turbidites. On one hand, there are LT1 types that are solely the result of reworked hemipelagic sediments, displaying a similar C/N ratio (algal imprint) as encountered for the hemipelagic “background” samples. On the other hand, there are the LT1 types also resulting from reworked hemipelagic sediments, but with a distinct trend to the field of C3 land plants (e.g. due to proximity to the lake banks, near steep slopes). The former is abbreviated as LT1- (lack of terrestrial + imprint) and the latter as LT1 (enriched in C3 derived OM). Data will be more elaborated in a section for each lake.

6.3.1 LAKE VILLARRICA

Core VI4 was taken in the southwestern sub-basin of the lake at a depth of 85 m (Fig. 4). The 1960

SED (T1) present in the core shows a subtle increase in C/N towards the C3 plants endmember with a maximum of 11.8, in comparison to the hemipelagic samples (~ 9.2; Fig. 12). This indicates that a limited amount of land plant derived material got involved in the deposit. No major landslides were reported during the 1960 earthquake, but numerous sightings of subsidence of beaches and deltas around the lake were observed. Grain size analysis suggests that the event deposit exists of reworked hemipelagic sediments (very fine silt) with some input of slightly coarser material at the base (very fine sandy, very coarse silt). Since the core was taken relatively close to the shoreline (approx. 1 km), sediments with a higher organic “background” from higher up the failing hemipelagic slope (closer to land) could explain the moderately elevated C/N ratios (Heirman, 2011). Another possible

47 explanation can be found in the reports. Observations of near-shore subsidence. Some of this subsided vegetation may have gotten included due to small-scale mass wasting, also explaining the observed trend towards the field of terrestrial vegetation. Since there is a distinctive trend towards land-based vegetation, this turbidite can be classified as a LT1+ type.

T2 at the top of core VI4 shows nearly identical C/N ratios as those observed in hemipelagic “background” sediments (~ 9.5). Grain size analysis of the event resulted in the determination of a very fine silt, again nearly identical to the hemipelagic “background” sediments. These results clearly suggest that the turbidite attributed to the 2010 earthquake is solely the consequence of reworked surficial hemipelagic slope sediments and can therefore be classified as a LT1- type turbidite. When comparing these results to T1 in the same core (VI4), assuming they had the same source area, a similar C/N signature is expected. Since this is not the case, the hypothesis of a near-shore mass wasting/subsidence seems more plausible for the 1960 event.

Core VI8 was also taken in the southwestern sub-basin (Fig. 4), about 2.5 km east of core VI4 at a depth of 113 m. T1 displays a clear trend towards the C3 field, with C/N values reaching a maximum at 14.9, compared to values of ~ 9.5 for the hemipelagic samples. These elevated values clearly suggest the incorporation of terrestrial vegetation in the turbidity flow. Grain size analysis of the event shows a thin relatively coarse base (very fine sandy, very coarse silt), immediately followed by sediments similar to the ones observed for the hemipelagic samples (fine silt). The sediment analysis implies reworked hemipelagic slope sediments, though there is a clear imprint of land based C3 vegetation. A possible hypothesis for this organic imprint can be found in the reports, identical to the 1960 SED in VI4: surrounding vegetation may have been incorporated in the turbidity flow due to subsidence/mass wasting, explaining the C3 land plant imprint in the sedimentary organic matter. + Based on the grain size analysis and the C3 imprint, this turbidite can be classified as an LT1 type.

T2 in core VI8 is similar to the contemporaneous event in core VI4. C/N ratios indicate values very much alike the ones observed in the hemipelagic samples (~ 8.5). Grain size analysis displays a sediment texture of fine to very fine silt, which is identical to the one observed for the “background” sediments. This data proposes sufficient evidence to conclude that the event deposit is the result of reworked hemipelagic slope sediments, hence the classification as a LT1- turbidite.

Core VI18 is situated west of a ridge in the southeastern part of the lake and was taken around a depth of 154 m (Fig. 4). Sediment description and grain size analysis clearly show two normally graded sequences stacked on top of each other. This is also confirmed by the C/N measurements, displaying a sharp boundary at the colour change of the sediment. In the lower (lighter) part of the SED, C/N values are somewhat higher (max. 11.7) than those observed for hemipelagic samples (~ 9.8). Grain size distribution of this part demonstrates the typical LT1 deposit type, where a thin relatively coarse base is immediately followed by sediments very similar as those seen in the hemipelagic “background” (medium to fine silt). The fact that the C/N ratios seem a little elevated is not surprising, since several riverine systems have their outlet nearby the southern hemipelagic slope proximal to the coring site, which is most likely the supplier of sediment for the observed event deposit. From these slopes, slightly organic richer hemipelagic sediments were transported in a turbidity current towards the basin floor. Considering the very limited difference in measured C/N ratios and lack of a clear trend towards a terrestrial signature, this lower (lighter) part of the SED can

48 be classified as a LT1- type. The upper (darker) part of the SED clearly has an organic richer imprint, with C/N values quickly rising to a maximum of 13.9. These values indicate an evident input of organic matter originating from vegetation following the C3 carbon fixation pathway. Grain size analysis shows an overall thicker sequence of coarser material (fine sandy, coarse silt) in comparison to the lower part of the SED, confirming the conjecture of another source area than the hemipelagic slopes. The fact that this overall coarser, more organic rich part of the SED is superimposed to the part originating from the hemipelagic slopes, indicates that the distance to the source area should be either considerably further or there was some delay between the start of both events, which is unlikely (no reports of mudflows a posteriori). Reports were made of near-shore subsidence and subsidence of beaches, which was also observed near one of the rivers inlets about 2.5 km south of the coring site (Fig. 4). Liquefaction of the partially saturated soil was also noted around the lake (sandblows). These reports together with the location of the coring site being relatively close to several riverine outlets, points in the direction of a destabilisation of the river delta(s). This could explain the obviously elevated C/N values and coarser sediments in comparison with the hemipelagic samples. For these reasons, the turbidite can be classified as a LT2 type.

Fig. 12. δ13C-values plotted against the C/N atomic ratios for all SEDs encountered in studied cores for Lake Villarrica. Turbidites attributed to the 1960 earthquake are marked red, those attributed to the 2010 earthquake are marked blue.

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6.3.2 LAKE CALAFQUÉN

Core CGC1 was cored in the eastern sub-basin at a depth around 178 m (Fig. 4). The base of the core shows the top part of the 1960 SED, also found in core CB4. Figure 13 displays an increase in δ13C- values compared to the hemipelagic “background” and a trend for C/N towards the C3 field. Though one value (sample CGC1 22.1-22.6) differs significantly from the other samples. Since this sudden trough in C/N ratios is not seen for the event in core CB4, no further relevance is given to this data point. C/N values reach a maximum at 14.0, which is considerably higher compared to the hemipelagic samples (~ 10.9). Grain size analysis indicates input of significantly coarser material (very coarse silty, very fine sand) than found in the hemipelagic samples (medium silt), especially since only the “fine grained” top of the SED is observed. Both datasets together suggest a source very close to land or even onshore. Local reports made during the 1960 earthquake state that the shores of the eastern sub-basin of Lake Calafquén were subjected to a lot of landslides. This fits the observations. When looking at core CB4, which was taken a few hundreds of meters northwest of core CGC1’s location at a similar depth, measured mean grain sizes seem to diminish. This implies that the distance to the source area becomes larger. During sampling, a substantial amount of coarse wood and leaf fragments were found at the base of the event deposit. C/N results also confirm the pronounced C3 land vegetation signature, with a maximum ratio as high as 17.0, compared to a “background” of ~ 10.2. This data also fits perfectly with the reports of landslides surging directly into the lake. Since the SED in core CGC1 has a coarser top in comparison with the one in core CB4, it most likely was closer to the source area. Taking the bathymetry and the surrounding relief into account, the most probable source area for such landslides, are the vegetated steep hill slopes about 1.5 km south of core CGC1 (Fig. 4), which were also reported after the earthquake (Wright and Mella, 1963). Both 1960 SEDs from cores CGC1 and CB4 can be classified as an LT2 type turbidite.

Core CB9 was taken in the western sub-basin of the lake at a depth around 170 m (Fig. 4). C/N results, grain size analysis and the sediment description clearly suggest that the observed SED exists of two separate events stacked on top of each other: a lower, lighter part and an upper, darker part. At the base of the lower part, fragments of woody material were found during sampling. A clear imprint of land-based pants was expected, but only a subtle increase can be detected. A possible cause for this is the poor homogenisation of the sample material. These coarser, robust wooden chips got left out while filling the small fragile silver capsules to avoid piercing while folding. Nevertheless, C/N ratios indicate elevated levels (max. 11.1) in comparison with hemipelagic samples (~ 9.4). Grain size distribution displays a relatively thick, very-coarse silty to very-fine sandy base, significantly coarser than encountered sediments for the hemipelagic samples. Combined data suggests a terrestrial source for this event deposit. Since reports state a lot of landslides during the 1960 earthquake, this is the most likely explanation to the origin of the deposit, also clarifying the presence of wood and leaf fragments. The lower (lighter) part can therefore be classified as a LT2 type. The upper part of the 1960 SED also displays slightly elevated C/N values (max. 10.9). Grain size analysis concluded a thin somewhat coarser base (fine sandy, coarse silt) with a subsequent deposits of sediments similar to the hemipelagic “background” samples (fine to very fine silt). The upper part of the event deposit therefore seems to be the result of reworked sediments from the hemipelagic slope, though with a subtle trend towards land-based plants. As a result, this turbidite may be classified as a LT1+ type, rather than a LT2 type.

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Core CALA05 was taken in the southwestern sub-basin at a depth of 88 m (Fig. 4). C/N measurements in the 1960 SED show very low values, similar to the ones observed in hemipelagic samples. Grain size analysis displays a typical LT1 deposit, where the base is marked by a thin deposit of coarser sediments (very-fine sandy, very-coarse silt) and followed by sediments nearly identical to the ones seen in hemipelagic samples (fine to very-fine silt). Consequently, this deposit is most likely the result of reworked hemipelagic slope sediments and thus can be classified as a LT1- type. The same goes for the 2010 SED at the top of core CALA05. C/N results and grain size analysis clearly suggest that the event deposit is solely the result of reworked sediments from the hemipelagic slope.

Core CALA08 is located around the center of the lake and taken at a depth of 194 m (Fig. 4). C/N atomic ratios are definitely elevated, with a measured maximum at 12.6, compared to ~ 8.8 for hemipelagic samples. A clear trend towards terrestrial plants can be observed. When looking at the grain size distribution, significantly coarser sediments (very-fine sandy, very-coarse silt to medium silt at the top) are encountered than the ones observed in hemipelagic samples (fine silt). This fits the description of a LT2 type turbidite. In a previous study by Van Daele et al. (2015), cores CALA09 and CALA10 (not used in this study), taken about 1.6 and 3.0 km eastwards respectively, were described containing a mass-transport deposit covered by a more heterogeneous LT2. In CALA08, this LT2 deposit becomes more homogenous. This suggests that the distance to the source area increases and this location most likely can be found somewhere on the flanks of the eastern sub-basin.

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Fig. 13. δ13C-values plotted against the C/N atomic ratios for all SEDs encountered in studied cores for Lake Calafquén. Turbidites attributed to the 1960 earthquake are marked red, those attributed to the 2010 earthquake are marked blue.

6.3.3 LAKE RIÑIHUE

Core RI5 was taken near the northwestern sub-basin of the lake at a depth of 121 m (Fig. 5). Grain size analysis, C/N results and the sediment description clearly suggest that the SED is the result of two density flows stacked on top of each other. Measured C/N ratios for the lower (darker) part display a distinct trend towards the field of land plants (Fig. 14), while the upper (lighter) part shows values in the range of the ones observed for hemipelagic samples. When looking at the lower part, the grain size distribution demonstrates significantly coarser material. This information together with the high C/N values (max. 14.6) implies a source area close to land or even onshore. The event can therefore be classified as a LT2 type. A similar, thicker LT2 deposit is found in core RI7, about 450 m north of core RI5. Both cores are in close proximity to a small river delta situated a bit northwest to the core locations. Since the LT2 deposit becomes thicker more proximal to this delta and roughly 600 m to the west (core RI8; see next paragraphs) this LT2 is not (barely) found anymore, a river- delta failure seems the most probable explanation for these deposits, confirming the hypothesis by Moernaut et al. (2014). The upper (lighter) part of the 1960 SED encountered in core RI5 displays C/N ratios and grain sizes very similar to the ones observed for hemipelagic samples. Since this deposit seems solely the result of reworked sediments originating from the hemipelagic slope, this event can be classified as a LT1- type.

Core RI7 is also located in the northwestern part of this sub-basin, about 450 metres north of core RI5 at a depth of 118 m (Fig. 5). The SED attributed to the 1960 earthquake (T1) also exists of two density flows stacked on top of each other, as determined by Moernaut et al. (2014). This is not so clear, based on the acquired data during this study. However, this could be because of the relatively “large” sample interval (0.5 mm) in comparison with the thickness of the upper density flow deposit (~ 1 cm). The lower part of T1 displays distinct characteristics of an LT2 type: very high C/N values (max. 26.1) and significantly coarser sediments compared to the regular hemipelagic sedimentation. This was expected since during sampling coarse leaf and wood fragments were found in the interval between 13.0 and 14.0 cm. The LT2 deposit is also found in core RI5, but seems to be thicker at this location and mean grain sizes are higher. This points to a closer proximity to the source area. Very high C/N values are observed for this lower deposit, with ratios directly in the field of terrestrial plants. Since the core location is around 600 m downslope of a small river delta, the most probable hypothesis is a delta failure with inclusion of lakeside vegetation. The upper deposit of T1 is similar to the LT1 observed in core RI5, though a lot smaller (1 cm vs. 5.5 cm) and somewhat coarser. In contrary to the LT1 in core RI5, C/N values still show a clear imprint of C3 vegetation. Therefore this turbidite can be classified as a LT1+ type.

The 2010 SED in core RI7 again carries a typical LT2 signature. C/N ratios (max. 16.5) show a clear trend towards terrestrial plant material and are significantly higher than the ones observed for hemipelagic “background” samples (~ 9.6). Grain size analysis points to a source with considerably coarser material than found on the hemipelagic slope. The SED appears to be very similar to the one attributed to the 1960 earthquake and also seems to be originating from the small delta on the

52 northern shore of the northwestern sub-basin, again confirming the hypothesis by Moernaut et al. (2014). These results clearly suggest that the C/N ratio is a valuable parameter that makes it easy to distinguish between both source areas.

Core RI8 is also taken in the northwestern sub-basin at a depth of 118 m (Fig. 5). The base displays

C/N ratios with a clear signature of C3 plants (max. 17.1), which was expected since some leaf and wood fragments were encountered during sampling (13.7 to 14.9 cm downcore). Furthermore, the grain size distribution points to very coarse material (very coarse silty, very fine sand), at least for the first centimetre of the SED. The remaining part of this deposit seems to show nearly identical C/N values and grain sizes as observed for hemipelagic samples. Since the base expresses such a strong influence from a land derived source, it might be a limb of the LT2 also observed in core RI5 and RI7, originating from the small river delta roughly 1 km northwards of the core location. Despite the very limited thickness of this deposit, it seems unlikely to be only the result of reworked hemipelagic sediments. It can thus be seen as a SED existing of 2 density flows stacked on top of each other. Therefore this base (13.7 to 14.9 cm downcore) can be classified as a LT2 type. Since the remaining part is nearly identical to the hemipelagic samples, this can be classified as a LT1- type.

Fig. 14. δ13C-values plotted against the C/N atomic ratios for all SEDs encountered in studied cores for Lake Riñihue. Turbidites attributed to the 1960 earthquake are marked red, those attributed to the 2010 earthquake are marked blue. The three yellow LT1 data points (Van Daele et al., 2015) with thick black borders can be classified as part of a limb of the LT2 deposit based on this newly gathered data.

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6.3.4 LAKE RUPANCO

Core RUP02BIS was taken in the eastern sub-basin of the lake, at a depth of 81 m (Fig. 5). C/N results show very stable values around 15-16 (Fig. 15). Compared to the hemipelagic samples (~ 12.2), the SED displays elevated C/N ratios, indicating sediment input from land. Grain size analysis determined that the megaturbidite is built of similar relatively fine grain sizes than the ones observed in “background” sedimentation, suggesting that a lot of sediments from the hemipelagic slope got included. The base of the megaturbidite was not cored, so no coarse fractions or any vegetation fragments are observed. Van Daele et al. (2013) noted that the top of the megaturbidite exists of two LT2 deposits. Due to the large sample interval (5 cm), only one LT2 could be distinguished at the very top (spike in mean grain size and C/N at 19.5 to 20.5 cm downcore). Based on the reports made during the 1960 earthquake, the megaturbidite is the result of landslides surging directly into the lake, together with mudflows originating from landslides that first converged on land. This new data can confirm the hypothesis by Van Daele et al. (2015), where the thick megaturbidite most likely finds its origin in the numerous landslides from the banks around the eastern sub-basin, while the LT2 deposit at the top most likely is the result of a delayed turbidity current from a mudflow.

Core RUP03TRIS is located in the western sub-basin and was taken at a depth of 44 m. Grain size distribution shows very low mean grain sizes throughout the whole sequence (medium to fine silt), nearly identical to one of the hemipelagic samples. “Background” sample RUP03TRIS 18.0-19.0 BS is not representative, displaying rather coarse material (very fine sandy, very coarse silt), and is therefore not taken into account. C/N ratios demonstrate some minor fluctuations, with a maximum value of 11.2, suggesting some minor input from land derived plant material following the C3 pathway. Based on this data, it is safe to conclude that the observed SED is the result of reworked hemipelagic slope sediments, where the upslope source sediments contained a slightly higher C3 plant signature than the regular hemipelagic sedimentation on this location. Therefore this deposit can be classified as a LT1+ type deposit.

Core RUP04 was drilled in the southern sub-basin of the lake, at a depth of 59 m. It hold a typical example of an LT2 type deposit. Mean grain sizes display significantly coarser material (very fine sandy, very coarse silt to coarse silt) than observed for the “background” sedimentation (medium silt) and C/N ratios clearly show a significant elevation towards the C3 land plants field (max. 17.1). Furthermore, leaf fragments were found throughout the sequence during sampling. Grain size distribution seems to display a delayed input from a second density flow in the interval between 15.3 and 16.3 cm (a sudden rise in mean-grain sizes is noted; Fig. 9). Taking the reports into consideration, the most likely source for this SED is material from landslides surging directly into the lake, together with converged material transported by the nearby river (about 3.3 km southeast) spilling into the lake.

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Fig. 15. δ13C-values plotted against the C/N atomic ratios for all SEDs encountered in studied cores for Lake Rupanco. Turbidites attributed to the 1960 earthquake are marked red, those attributed to the 2010 earthquake are marked blue.

6.4 POTENTIAL OF C/N

C/N atomic ratios of bulk organic matter in lacustrine turbidites can be used as an easy tool in determining whether the sediments rather have a (partially) terrestrial source or not, in comparison with the regular hemipelagic sedimentation. This together with a good understanding of the lake’s surrounding vegetation, watershed and bathymetry makes it possible to construct a highly probable hypothesis of the provenance of the turbidite. Though, the usefulness of this method most likely depends on the study site. The four lakes in this thesis display low stable C/N ratios around 8 to 10 for hemipelagic sediments (algal imprint due to high productivity), while sediments originating from the lake’s surrounding slopes, near-shore areas and river delta give significantly elevated C/N ratios, resulting in a clear distinction between a terrestrial or subaquatic sediment source. For areas where “background” sedimentation shows higher and/or more variable C/N ratios (lower algal production), distinction between source areas might be more complicated. In addition, the C/N ratio of every organic matter source may vary greatly, even between plants within the same type of carbon fixation group (e.g. C3: black locust vs. eucalyptus). In general, this method should work for different types of vegetation covers, though the distinction between source areas might be more/less clear for certain types of vegetation in the watershed.

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7. CONCLUSIONS

The C/N atomic ratio in combination with sediment grain size analysis is a very useful parameter to distinguish between several source areas in a lacustrine environment. Most clear results were given by SEDs originating from hemipelagic slope failure, where there is a clear imprint of organic matter from freshwater algae, and SEDs originating from landslides surging either directly/indirectly into the lake or as a result of river delta foreset failure, with a strong signature of terrestrial material. Though, a good understanding of the lake’s surrounding and bathymetry is imperative for a useful interpretation. All analysed turbidites where seismically triggered, so no C/N related characteristics of flood deposits or lahars could be studied, which might be interesting for future research.

One of the goals in this study was to determine whether there was any relationship between the C/N ratio and the grain size distribution. The relationship between N/C and grain size in general shows a negative tendency, though no consistent trend can be observed between the different SEDs. C/N is not only driven by grain size (e.g. core RUP02BIS, very fine mean grain sizes and low N/C ratios vs. core CALA05, for same grain sizes very high N/C ratios) and can therefore be used as a proxy to trace the source area of the sedimentary organic matter. The ratios seem to be to an ideal tool to disentangle contributions from aquatic and terrestrial organic matter sources in a lacustrine enironment. Though, the method is most likely limited to study areas characterised by high algal productivity (low stable C/N “background” values) in order to clearly distinguish terrestrial imprints.

Furthermore, based on this new dataset (n = 206), a more accurate regression model could be constructed (R² = 93.6 %), relating LOI550 and TOC for the lakes Villarrica, Calafquén, Riñihue and Rupanco (Chilean Lake District). It can also be noted that the relationship between both quantities displays a seemingly higher variability for samples with a relatively high content of organic material

(LOI550 > 10 %).

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9. NEDERLANDSTALIGE SAMENVATTING

Een goed inzicht in het brongebied van lacustriene turbidieten kan de interpretatie van sediment cores verbeteren en helpen in het reconstrueren van slope failure processen of in het begrijpen van de events verantwoordelijk voor de sedimentdeformatie (bv. aardbevingen en floods). Vele studies zijn reeds voorafgegaan, maar in deze thesis wordt een alternatieve parameter getest om de oorsprong van de turbidieten te bepalen, nl. het koolstrof-stikstof (C/N) ratio. Dit ratio geeft de atoomverhouding van organisch koolstof tot stikstof weer en wordt vaak gebruikt in paleoklimatologisch onderzoek. Algemeen kan men stellen dat organisch materiaal van algen een C/N ratio heeft van ongeveer 4 tot 8, terwijl dat van hogere landplanten (phylum Tracheophyta) een C/N ratio heeft ≥ 20 (Premuzic et al, 1982;. Jasper en Gagosian, 1990; Meyers, 1994; Prahl et al., 1994). Na de begraving van het organisch materiaal in meersedimenten, wordt de elementaire verhouding van koolstof en stikstof voldoende bewaard om de vasculaire/non-vasculaire signalen te herkennen (Meyers and Ishiwatari, 1993; Meyers, 1994). Daarom kunnen veranderingen in het C/N ratio in lacustriene sedimenten geïnterpreteerd worden als zijnde verschuivingen in brondgebied, waarbij het organisch materiaal eerder neigt naar een terrestrische signatuur of afkomstig is van algen (Ishiwatari and Uzaki, 1987). Bovendien kan deze verhouding ook worden gebruikt om te differentiëren tussen bepaalde groepen landplanten, afhankelijk van het soort koolstoffixatie ze gebruiken (bv. C3 en C4 planten). Dit maakt deze methode een handig instrument voor het bepalen van brongebieden van sedimentair organisch materiaal.

Het doel van deze thesis is om te onderzoeken in welke mate het C/N ratio kan gebruikt worden om onderscheid te maken tussen brongebieden van lacustriene turbidieten, zoals hemipelagische slope failures, rivierdelta failures, onshore landslides, flood gerelateerde events, modderstromen, etc. In een volgende fase wordt er onderzocht of er een verband is met de korrelgrootteverdeling, daar het C/N ratio vaak nauw samenhangt met de korrelgrootte van de klastische component (Howarth et al., 2014). Uiteindelijk, als de vergaarde data en historische rapporten een consistente correlatie vertonen, kan deze methode aangewend worden als een proxy voor long cores in toekomstig lacustrien paleoseismisch/klimatologisch onderzoek. Om een antwoord hierop te vinden, werden 18 turbidieten van gekende oorsprong bemonsterd uit een reeks van cores genomen in verschillende sedimentaire omgevingen.

Het studiegebied situeert zich in Zuid-Centraal Chili en is meer bepaald gericht op vier grote meren die deel uitmaken van het Chilean Lake District (39°Z-41°Z): het Villarica, Calafquén, Riñihue en Rupanco Meer. Alle meren zijn gelegen aan de voet van het Andesgebergte en vertonen een gelijkaardige morfologie, limnologie en klimaat. De turbidieten zijn het gevolg van enerzijds de 1960

Valdivia aardbeving (Mw 9.5) en anderzijds de 2010 Maule aardbeving (Mw 8.8). Deze vinden hun oorsprong in de aanhoudende oblieke subductie van de Nazcaplaat onder de Zuid-Amerikaanse Plaat langsheen de Peru-Chilitrog.

De 14 cores gebruikt in deze studie zijn afkomstig van twee expedities in 2009 en 2011 (Van Daele, 2013; Moernaut et al., 2014; Van Daele et al., 2014; Van Daele et al., 2015). Per turbidiet werden er twee hemipelagische “achtergrond” samples genomen met een dikte van 1 cm. De turbidieten werden doorlopend gesampled met een sample interval van 0.5 cm indien < 8 cm en een sample interval van 1 cm indien > 8 cm. Een uitzondering hierbij was de megaturbidiet in core RUP02BIS, die

65 omwille van zijn lengte om de 5 cm werd gesampled met een sample dikte van 1 cm. Vervolgens werden alle 218 samples gevriesdroogd, gemalen en gehomogeniseerd alvorens van start te gaan met de analyses.

Als eerste analyse werd LOI (Loss On Ignition) uitgevoerd om een schatting te maken van de inhoud organisch koolstof voor ieder staal. Op basis hiervan kan een ruwe waarde berekend worden van het TOC, zodat de hoeveelheid benodigd sediment voor een goede koolstof en stikstof elemental and isotopic analysis kan geoptimaliseerd worden. De LOI methode is gebaseerd op het opeenvolgend verhitten en wegen van de sediment samples volgens het protocol beschreven door Heiri et al. (2001). Twee cycli werden doorlopen. Hierbij werden de stalen eerst verhit tot 105 °C gedurende 24 uur om het residuele vocht uit de kleien te verdrijven, waarna ze nogmaals verhit werden tot 550 °C om het organisch materiaal te verbranden.

Vervolgens werden TOC waarden geschat volgens de empirische formule van Bartels (2012) en Paesbrugge (2013) en werd er een ideale hoeveelheid sediment voor ieder sample bepaald. Zilvercapsules werden gevuld met het desbetreffende gewicht voor ieder sample, aangezuurd met 60 µl zwavelzuur (5-6 %) om anorganisch koolstof te verwijderen, toegeplooid en geordend in 96-well trays. Deze trays werden vervolgens opgestuurd naar het UC Davis Stable Isotope Facility (U.S., California). Hier werd de hoeveelheid (µg) koolstof en stikstof bepaald door de EA-IRMS (Elemental Analyser verbonden met een continuous flow Isotope Ratio Mass Spectrometer). Door deze hoeveelheden te delen door de gemeten gewichten van de samples, verkrijgt men de TOC en TN waarden. Vervolgens werden ook de deltawaarden van de stabiele isotopen 13C en 15N gemeten. De C/N ratios in combinatie met de δ13C waarden kunnen helpen om onderscheid te maken tussen verschillende bronnen van organisch materiaal. Echter, aangezien de turbidieten afkomstig zijn van brongebieden met zowel een soortgelijke samenstelling van gelamineerde hemipelagische sedimenten als van onshore gebieden, kunnen we δ13C-waarden verwachten in het bereik van -25 tot -30 ‰. Deze range komt overeen met de waarden van al het levend aquatisch organisch materiaal en 13 de C3 landplanten. Aangezien beiden in hetzelfde bereik liggen, zullen de δ C-waarden geen verdere informatie verschaffen in het onderscheiden van brongebieden. Vandaar het belang en de interesse in C/N ratios. Deze zullen variëren tussen de eindleden van lacustrine algen (4-8) en C3 planten (≥ 20), naargelang de vermenging met landmateriaal.

Gemiddelde korrelgroottes van ieder sample werden bepaald met behulp van een Malvern Mastersizer 3000 laser diffraction particle-size analyser. De analyse werd uitgevoerd op de siliciklastische fractie. Samples werden eerst behandeld met H2O2 (35 %), HCl (10 %) en NaOH (8 %) om organisch materiaal, carbonaten en biogene silica respectievelijk te verwijderen. Om een volledige disaggregatie van het samplemateriaal te verkrijgen, alvorens met de meting van start te gaan, werd bij ieder sample 1 ml hexametafosfaat (2 %) toegevoegd.

Acheteraf werden LOI550 metingen en TOC data (n = 206) onderling vergeleken. Vrijwel alle events vertoonden een zeer sterke positieve lineaire correlatie. Alle datapunten werden uitgezet in een scatterplot, waar vervolgens een lineaire, polynomiale en machtsregressie werden op toegepast. Hierbij leverde de laatste de hoogste determinatiecoëfficient op (R² = 0.936). Een gelijkaardige relatie als die van Bartels (2012) en Paesbrugge (2013) werd waargenomen, hoewel deze de TOC percentages van de gebruikte samples steeds licht onderschatten. Hetgeen werd opgemerkt in de

66 scatterplot, is dat de relatie tussen LOI550 en TOC bij hogere waarden voor organisch materiaal (LOI550 > 10 %) een steeds hogere spreiding vertonen. Een mogelijke verklaring voor deze fluctuaties is het verschil in TOC-gehalte tussen organisch materiaal afkomstig van algen en organisch materiaal afkomstig van houtige planten (bv. OM van diatomeeën heeft een gemiddeld TOC-gehalte van 25 %, terwijl voor OM van hout TOC varieert van 35 tot 65 %; Hedges, 1975; Walsh, 1983). Vandaar dat in een zuurstofrijk facies het TOC-gehalte vaak wordt bepaald door de variaties in absolute phytoclast abundantie (Tyson, 1995). Niettemin kan LOI550 worden beschouwd als een zeer nuttig hulpmiddel in het schatten van TOC op een lokale schaal en om de hoeveelheid sediment voor elemental and isotopic analysis van vaste materialen te optimaliseren.

In een volgende stap werd gekeken naar de relatie tussen het C/N ratio en de gemiddelde korrelgrootte. Aangezien het meestal de hoeveelheid stikstof is die verandert in de de verschillende soorten organisch materiaal en niet de hoeveelheid koolstof, zijn de C/N waarden geïnverteerd (N/C) om een meer lineaire relatie te verkrijgen (Perdue en Koprivnjak, 2007). Echter, hierbij werd geen consistente relatie gevonden, maar eerder een hoge variabiliteit in correlatiecoëfficienten. Enkel de events in cores VI4, CGC1 en deze genomen in het Riñihue Meer vertoonden een significante negatieve relatie tussen het N/C ratio en de gemiddelde korrelgrootte (p < 0.05). Bij deze waar er een significante relatie herkend werd, valt de grove fractie samen met de laagst gemeten N/C ratios (hoogste C/N ratios) en vice versa. In alle andere onderzochte turbidieten komen de pieken en dalen tussen beide variabelen niet overeen. Op basis van de scatterplot kan gesteld worden dat de relatie (N/C en korrelgrootte), indien aanwezig, negatief is en een relatief goede lineaire correlatie kan vertonen indien terrestrisch materiaal opgenomen werd in de turbidiet (LT2 types). De megaturbidiet in core RUP02BIS toont aan dat deze relatie niet altijd opgaat. Hier werden lage N/C ratios geobserveerd ondanks dat de fractie zeer fijnkorrelig is. Het feit dat deze fijnkorrelige top dergelijke lage N/C waarden vertoont, suggereert dat de gehele megaturbidiet hoogstwaarschijnlijk zijn oorsprong vindt op land. In dit voorbeeld is N/C volledig onafhankelijk van de korrelgrootte. Een andere interessante observatie zijn de schijnbare “vertraagde” pieken voor C/N waarden in vergelijking met de grofste korrelgrootte. Een mogelijke verklaring hiervoor kan te vinden zijn in het verschil in bezinkingssnelheid tussen grovere korrels en organisch materiaal (bv. plantfragmenten), waarbij het organisch materiaal trager in de waterkolom naar beneden beweegt vanwege zijn vorm, gewicht en drijfvermogen.

In een slotfase werd alle vergaarde data geïnterpreteerd in combinatie met de historische verslagen van het 1960 en 2010 event. Op basis hiervan konden weloverwogen hypotheses van de brongebieden van de turbidieten opgesteld worden. De C/N ratios werden vergeleken met hun “achtergrond” om te achterhalen of er een duidelijke bijdrage was van sedimentair organisch materiaal vanop land (bv. via onshore lanslides, delta failure, modderstromen), of indien het louter ging om herwerkte hemipelagische sedimenten door subaquatic slope failure. De indeling van de turbidieten (LT1 en LT2) is gebaseerd op Van Daele et al. (2015). Het LT1 type bestaat hoofdzakelijk uit herwerkte hemipelagische slope sedimenten en is het resultaat van lateral slope failure. Het LT2 type wijkt hiervan af door een grovere samenstelling te hebben dan de “achtergrond” en is meestal gekenmerkt door een duidelijke terrestrische signatuur. Afhankelijk van de verrijking met organisch materiaal kan er nog een onderscheid gemaakt worden binnen de LT1 types. Enerzijds zijn er LT1‘s die uitsluitend het gevolg zijn van herwerkte hemipelagische sedimenten, waarbij een vergelijkbaar C/N ratio (algen signatuur) wordt aangetroffen als voor de hemipelagische "achtergrond" samples.

67

Anderzijds zijn er de LT1 types die ook voortvloeien uit herwerkte hemipelagische sedimenten, maar met een duidelijke invloed van terrestrisch organisch materiaal (bv. door subsidence, mass wasting, vermenging met top slope hemipelagisch sedimenten met hoger C/N). Diegene zonder terrestrische imprint worden afgekort als LT1-, terwijl diegene met een duidelijke trend worden afgekort als LT1+.

De meest duidelijke resultaten werden gegeven door turbidieten afkomstig van hemipelagische slope failure, waar sprake is van een duidelijke signatuur van organisch materiaal afkomstig van algen, en turbidieten die afkomstig zijn van landslides die zich ofwel direct/indirect in het meer storten of als gevolg van een rivierdelta foreset failure, met een onmiskenbare signatuur van terrestrisch materiaal. Echter, een goed begrip van de omgeving van het meer en bathymetrie is absoluut noodzakelijk om tot een betrouwbare hypothese te komen.

Eén van de andere doelen van deze studie was om te bepalen of er een relatie is tussen het C/N ratio en de korrelgrootteverdeling. De relatie tussen N/C en de korrelgrootte toont in het algemeen een negatieve trend aan, maar is niet consistent. Hieruit kan opgemaakt worden dat C/N niet enkel gedreven wordt door de korrelgrootte (bv. core RUP02BIS, zeer fijne gemiddelde korrelgrootte en lage N/C-verhoudingen vs. core CALA05 voor dezelfde korrelgrootte hoge N/C verhouding) en kan daarom gebruikt worden als een proxy om de herkomst van het sedimentair organisch materiaal op te sporen. De ratios lijken een ideaal hulpmiddel te zijn om brongebieden van aquatisch en terrestrisch organische materiaal te onderscheiden. Echter, de methode is hoogstwaarschijnlijk beperkt tot gebieden die gekenmerkt worden door een hoge algenproductiviteit (lage stabiele C/N "achtergrond") om een duidelijk onderscheid te kunnen maken in terrestrische signaturen.

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10. APPENDIX

TABLE OF CONTENTS

1. Results LOI measurements…………………………………………………………………………………………………70

2. Results bulk organic geochemical analysis……………………………………………………………………………79

3. Results grain size analysis…………………………………………………………………………………………………….83

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1. RESULTS LOI MEASUREMENTS

Crucible Freeze dried sample weight (g) Dry (105ºC) sample weight (g) OM content Sample label Weight Sample Sample Notes Nr Crucible + sample (g) Crucible + sample (g) Crucible + sample (g) Sample (g) Δ LOI550 (%) (g) (g) (g)

RUP04 6.3-7.3 34 21.1804 22.1860 1.0056 22.1496 0.9692 21.9888 0.8084 0.1608 16.59

RUP04 7.3-8.3 28 20.4614 21.4611 0.9997 21.4398 0.9784 21.2737 0.8123 0.1661 16.98

RUP04 8.3-9.3 45 17.8142 18.8122 0.9980 18.7872 0.9730 18.6229 0.8087 0.1643 16.89

RUP04 9.3-10.3 6 18.2212 19.2186 0.9974 19.1967 0.9755 19.0268 0.8056 0.1699 17.42

RUP04 10.3-11.3 13 17.1097 18.1115 1.0018 18.0915 0.9818 17.9127 0.8030 0.1788 18.21 Leaf fragments throughout

RUP04 11.3-12.3 16 20.3335 21.3330 0.9995 21.3091 0.9756 21.1459 0.8124 0.1632 16.73

RUP04 12.3-13.3 2 17.7386 18.7334 0.9948 18.7095 0.9709 18.5449 0.8063 0.1646 16.95

RUP04 13.3-14.3 40 17.4614 18.4634 1.0020 18.4472 0.9858 18.2929 0.8315 0.1543 15.65

RUP04 14.3-15.3 46 18.6412 19.6417 1.0005 19.6234 0.9822 19.4725 0.8313 0.1509 15.36

RUP04 15.3-16.3 37 20.6015 21.6034 1.0019 21.5839 0.9824 21.4191 0.8176 0.1648 16.78

RUP04 16.3-17.3 15 21.1906 22.2003 1.0097 22.1710 0.9804 22.0140 0.8234 0.1570 16.01

RUP04 17.3-18.3 21 21.0365 22.0337 0.9972 22.0084 0.9719 21.8673 0.8308 0.1411 14.52

RUP04 18.3-19.3 36 17.8247 18.8267 1.0020 18.8009 0.9762 18.7134 0.8887 0.0875 8.96

RUP04 21.0-22.0 BS 17 18.4189 19.4134 0.9945 19.3743 0.9554 19.2435 0.8246 0.1308 13.69

RUP04 22.0-23.0 BS 7 17.8807 18.8845 1.0038 18.8551 0.9744 18.7366 0.8559 0.1185 12.16

CGC1 21.1-21.6 19 20.1579 21.1528 0.9949 21.1481 0.9902 21.1313 0.9734 0.0168 1.70

CGC1 21.6-22.1 11 19.7439 20.7472 1.0033 20.7439 1.0000 20.7315 0.9876 0.0124 1.24

CGC1 22.1-22.6 4 20.6923 21.6947 1.0024 21.6905 0.9982 21.6765 0.9842 0.0140 1.40

CGC1 22.6-23.1 10 17.0979 18.0932 0.9953 18.0919 0.9940 18.0748 0.9769 0.0171 1.72

CGC1 23.1-23.6 30 17.5169 18.5158 0.9989 18.5145 0.9976 18.4997 0.9828 0.0148 1.48

CGC1 23.6-24.1 22 20.7104 21.7116 1.0012 21.7088 0.9984 21.6918 0.9814 0.0170 1.70

CGC1 24.1-24.6 23 19.1810 20.1884 1.0074 20.1846 1.0036 20.1674 0.9864 0.0172 1.71

70

CGC1 24.6-25.0 3 17.7999 18.7939 0.9940 18.7922 0.9923 18.7680 0.9681 0.0242 2.44

CGC1 2.0-3.0 BS 31 21.3405 22.3484 1.0079 22.3394 0.9989 22.2624 0.9219 0.0770 7.71

CGC1 3.0-4.0 BS 14 20.1813 21.1823 1.0010 21.1672 0.9859 21.0761 0.8948 0.0911 9.24

CALA08 0.5-1.5 20 21.3192 22.3161 0.9969 22.2928 0.9736 22.2313 0.9121 0.0615 6.32

CALA08 1.5-2.5 24 21.4584 22.4561 0.9977 22.4392 0.9808 22.3743 0.9159 0.0649 6.62

CALA08 2.5-3.5 25 19.3763 20.3746 0.9983 20.3594 0.9831 20.2925 0.9162 0.0669 6.81

CALA08 3.5-4.5 39 20.1059 21.1074 1.0015 21.0957 0.9898 21.0293 0.9234 0.0664 6.71

CALA08 4.5-5.5 8 16.6930 17.6950 1.0020 17.6833 0.9903 17.6099 0.9169 0.0734 7.41

CALA08 5.5-6.5 1 17.9033 18.9038 1.0005 18.8895 0.9862 18.8186 0.9153 0.0709 7.19

CALA08 6.5-7.5 32 21.6009 22.6048 1.0039 22.5872 0.9863 22.5167 0.9158 0.0705 7.15

CALA08 7.5-8.5 43 18.4379 19.4350 0.9971 19.4235 0.9856 19.3500 0.9121 0.0735 7.46

CALA08 8.5-9.5 12 18.6029 19.6054 1.0025 19.5928 0.9899 19.5307 0.9278 0.0621 6.27

CALA08 9.5-10.5 44 16.9825 17.9893 1.0068 17.9801 0.9976 17.9210 0.9385 0.0591 5.92

CALA08 10.5-11.5 49 20.4072 21.4042 0.9970 21.3891 0.9819 21.3231 0.9159 0.0660 6.72

CALA08 11.5-12.0 26 19.6366 20.6365 0.9999 20.6240 0.9874 20.5684 0.9318 0.0556 5.63

CALA08 14.0-15.0 BS 72 21.0050 22.0033 0.9983 21.9749 0.9699 21.8799 0.8749 0.0950 9.79

CALA08 15.0-16.0 BS 27 20.4962 21.4965 1.0003 21.4751 0.9789 21.3742 0.8780 0.1009 10.31

RI8 8.7-9.2 5 20.4290 21.4271 0.9981 21.3909 0.9619 21.3026 0.8736 0.0883 9.18

RI8 9.2-9.7 18 18.2662 19.2645 0.9983 19.2283 0.9621 19.1369 0.8707 0.0914 9.50

RI8 9.7-10.2 41 21.1077 22.1080 1.0003 22.0654 0.9577 21.9764 0.8687 0.0890 9.29

RI8 10.2-10.7 60 17.5537 18.5575 1.0038 18.5205 0.9668 18.4279 0.8742 0.0926 9.58

RI8 10.7-11.2 9 20.8092 21.8082 0.9990 21.7689 0.9597 21.6795 0.8703 0.0894 9.32

RI8 11.2-11.7 38 18.6961 19.6570 0.9609 19.6220 0.9259 19.5325 0.8364 0.0895 9.67

RI8 11.7-12.2 35 19.8735 20.8714 0.9979 20.8353 0.9618 20.7513 0.8778 0.0840 8.73

RI8 12.2-12.7 29 21.6756 22.6745 0.9989 22.6332 0.9576 22.5462 0.8706 0.0870 9.09

RI8 12.7-13.2 33 21.0936 22.0929 0.9993 22.0564 0.9628 21.9667 0.8731 0.0897 9.32

RI8 13.2-13.7 57 18.0432 19.0451 1.0019 19.0183 0.9751 18.9250 0.8818 0.0933 9.57

71

RI8 13.7-14.2 68 20.8523 21.8556 1.0033 21.8189 0.9666 21.7027 0.8504 0.1162 12.02 Wood fragments

RI8 14.2-14.7 52 18.2702 19.2774 1.0072 19.2602 0.9900 19.1446 0.8744 0.1156 11.68 Wood fragments

RI8 14.7-14.9 61 20.9544 21.9539 0.9995 21.9417 0.9873 21.8521 0.8977 0.0896 9.08 Wood + leaf fragments

RI8 16.0-17.0 BS 56 20.6406 21.6455 1.0049 21.6268 0.9862 21.5257 0.8851 0.1011 10.25

RI8 22.0-23.0 BS 66 20.8435 21.8429 0.9994 21.8230 0.9795 21.7638 0.9203 0.0592 6.04

CALA05 0.0-0.5 71 17.9710 18.9716 1.0006 18.9374 0.9664 18.8313 0.8603 0.1061 10.98

CALA05 0.5-1.0 59 17.2001 18.1212 0.9211 18.0888 0.8887 17.9935 0.7934 0.0953 10.72

CALA05 1.0-1.5 47 17.7777 18.7720 0.9943 18.7346 0.9569 18.6232 0.8455 0.1114 11.64

CALA05 3.0-4.0 BS 70 21.5773 22.5799 1.0026 22.5450 0.9677 22.4447 0.8674 0.1003 10.36

CALA05 4.0-5.0 BS 48 16.7090 17.7012 0.9922 17.6541 0.9451 17.5528 0.8438 0.1013 10.72

CALA05 6.5-7.0 67 17.7582 18.7533 0.9951 18.7301 0.9719 18.6393 0.8811 0.0908 9.34

CALA05 7.0-7.5 62 20.7076 21.7068 0.9992 21.6755 0.9679 21.5961 0.8885 0.0794 8.20

CALA05 7.5-8.0 76 21.8173 22.8114 0.9941 22.7772 0.9599 22.6985 0.8812 0.0787 8.20

CALA05 8.0-8.5 58 17.6246 18.6216 0.9970 18.5892 0.9646 18.5070 0.8824 0.0822 8.52

CALA05 8.5-9.0 51 20.6903 21.6975 1.0072 21.6695 0.9792 21.5771 0.8868 0.0924 9.44

CALA05 9.0-9.5 54 18.5409 19.5466 1.0057 19.5176 0.9767 19.4345 0.8936 0.0831 8.51

CALA05 9.5-10.0 3 17.7994 18.7947 0.9953 18.7693 0.9699 18.6844 0.8850 0.0849 8.75

CALA05 10.0-10.5 75 21.1023 22.1014 0.9991 22.0683 0.9660 21.9846 0.8823 0.0837 8.66

CALA05 10.5-11.0 36 17.8245 18.8219 0.9974 18.8052 0.9807 18.7421 0.9176 0.0631 6.43

CALA05 13.0-14.0 BS 31 21.3399 22.3359 0.9960 22.2844 0.9445 22.2042 0.8643 0.0802 8.49

CALA05 14.0-15.0 BS 10 17.0977 18.0915 0.9938 18.0528 0.9551 17.9622 0.8645 0.0906 9.49

CB4 1.2-2.2 BS 30 17.5162 18.5153 0.9991 18.4831 0.9669 18.3871 0.8709 0.0960 9.93

CB4 2.2-3.2 BS 11 19.7435 20.7455 1.0020 20.7162 0.9727 20.6264 0.8829 0.0898 9.23

CB4 14.8-15.3 46 18.6410 19.6429 1.0019 19.6185 0.9775 19.5719 0.9309 0.0466 4.77

CB4 15.3-15.8 79 20.6985 21.6919 0.9934 21.6700 0.9715 21.6161 0.9176 0.0539 5.55

CB4 15.8-16.3 50 21.0735 22.0750 1.0015 22.0578 0.9843 21.9993 0.9258 0.0585 5.94

CB4 16.3-16.8 73 21.2599 22.2545 0.9946 22.2308 0.9709 22.1754 0.9155 0.0554 5.71

72

CB4 16.8-17.3 53 18.7942 19.7938 0.9996 19.7673 0.9731 19.7143 0.9201 0.0530 5.45

CB4 17.3-17.8 77 21.4111 22.4188 1.0077 22.3956 0.9845 22.3376 0.9265 0.0580 5.89

CB4 17.8-18.3 69 20.4485 21.4485 1.0000 21.4256 0.9771 21.3705 0.9220 0.0551 5.64

CB4 18.3-18.8 64 19.8095 20.8080 0.9985 20.7808 0.9713 20.7254 0.9159 0.0554 5.70

CB4 18.8-19.3 65 19.5925 20.5928 1.0003 20.5698 0.9773 20.5081 0.9156 0.0617 6.31 Wood chips

CB4 19.3-19.8 55 17.5662 18.5647 0.9985 18.5373 0.9711 18.4590 0.8928 0.0783 8.06 Leaf + wood fragments

CB4 19.8-20.3 78 18.0544 19.0503 0.9959 19.0280 0.9736 18.9331 0.8787 0.0949 9.75 Leaf + wood fragments

CB4 20.3-20.8 22 20.7102 21.7133 1.0031 21.6916 0.9814 21.6344 0.9242 0.0572 5.83 Wood chips

CB4 20.8-21.3 74 20.7689 21.7663 0.9974 21.7461 0.9772 21.6932 0.9243 0.0529 5.41 Wood chips

VI18 0.0-0.5 63 21.0376 22.0358 0.9982 21.9968 0.9592 21.9212 0.8836 0.0756 7.88

VI18 0.5-1.0 7 17.8810 18.8821 1.0011 18.8540 0.9730 18.7940 0.9130 0.0600 6.17

VI18 1.0-1.5 2 17.7390 18.7395 1.0005 18.7134 0.9744 18.6512 0.9122 0.0622 6.38

VI18 1.5-2.0 15 21.1912 22.1940 1.0028 22.1738 0.9826 22.1112 0.9200 0.0626 6.37

VI18 2.0-2.5 37 20.6017 21.6014 0.9997 21.5800 0.9783 21.5142 0.9125 0.0658 6.73

VI18 2.5-3.0 16 20.3333 21.3380 1.0047 21.3059 0.9726 21.2359 0.9026 0.0700 7.20

VI18 3.0-3.5 34 21.1801 22.1829 1.0028 22.1481 0.9680 22.0692 0.8891 0.0789 8.15

VI18 3.5-4.0 21 21.0367 22.0336 0.9969 21.9943 0.9576 21.9182 0.8815 0.0761 7.95

VI18 4.0-4.5 14 20.1812 21.1859 1.0047 21.1479 0.9667 21.0745 0.8933 0.0734 7.59

VI18 4.5-5.0 17 18.4190 19.4141 0.9951 19.3899 0.9709 19.3133 0.8943 0.0766 7.89

VI18 5.0-5.5 40 17.4613 18.4641 1.0028 18.4561 0.9948 18.4214 0.9601 0.0347 3.49

VI18 7.0-8.0 BS 28 20.4615 21.4690 1.0075 21.4306 0.9691 21.3314 0.8699 0.0992 10.24

VI18 8.0-9.0 BS 19 20.1577 21.1551 0.9974 21.1192 0.9615 21.0303 0.8726 0.0889 9.25

RUP03TRIS 5.5-6.0 55 17.5665 18.5644 0.9979 18.5195 0.9530 18.4426 0.8761 0.0769 8.07

RUP03TRIS 6.0-6.5 67 17.7577 18.7513 0.9936 18.7105 0.9528 18.6257 0.8680 0.0848 8.90

RUP03TRIS 6.5-7.0 17 18.4205 19.4296 1.0091 19.3875 0.9670 19.3053 0.8848 0.0822 8.50

RUP03TRIS 7.0-7.5 36 17.8248 18.8247 0.9999 18.7760 0.9512 18.7022 0.8774 0.0738 7.76

RUP03TRIS 7.5-8.0 37 20.6021 21.6101 1.0080 21.5641 0.9620 21.4824 0.8803 0.0817 8.49

73

RUP03TRIS 8.0-8.5 59 17.2007 18.2084 1.0077 18.1650 0.9643 18.0745 0.8738 0.0905 9.39

RUP03TRIS 8.5-9.0 31 21.3409 22.3497 1.0088 22.2956 0.9547 22.2217 0.8808 0.0739 7.74

RUP03TRIS 9.0-9.5 62 20.7083 21.7025 0.9942 21.6491 0.9408 21.5705 0.8622 0.0786 8.35

RUP03TRIS 9.5-10.0 Not enough sample material

RUP03TRIS 10.0-10.5 28 20.4611 21.4674 1.0063 21.4127 0.9516 21.3347 0.8736 0.0780 8.20

RUP03TRIS 10.5-11.0 10 17.0973 18.0956 0.9983 18.0418 0.9445 17.9655 0.8682 0.0763 8.08

RUP03TRIS 11.0-11.5 11 19.7442 20.7434 0.9992 20.6907 0.9465 20.6103 0.8661 0.0804 8.49

RUP03TRIS 11.5-12.0 46 18.6421 19.6034 0.9613 19.5540 0.9119 19.4767 0.8346 0.0773 8.48

RUP03TRIS 12.0-12.5 58 17.6251 18.6292 1.0041 18.5802 0.9551 18.5023 0.8772 0.0779 8.16

RUP03TRIS 12.5-13.0 21 21.0361 22.0357 0.9996 21.9857 0.9496 21.9111 0.8750 0.0746 7.86

RUP03TRIS 13.0-13.5 47 17.7779 18.7725 0.9946 18.7257 0.9478 18.6494 0.8715 0.0763 8.05

RUP03TRIS 13.5-14.0 78 18.0544 19.0562 1.0018 19.0125 0.9581 18.9349 0.8805 0.0776 8.10

RUP03TRIS 14.0-14.5 2 17.7388 18.7331 0.9943 18.6896 0.9508 18.6139 0.8751 0.0757 7.96

RUP03TRIS 14.5-15.0 34 21.1802 22.1829 1.0027 22.1269 0.9467 22.0468 0.8666 0.0801 8.46

RUP03TRIS 15.0-15.5 14 20.1814 21.1844 1.0030 21.1168 0.9354 21.0349 0.8535 0.0819 8.76

RUP03TRIS 17.0-18.0 BS 56 20.6397 21.6331 0.9934 21.5822 0.9425 21.5053 0.8656 0.0769 8.16

RUP03TRIS 18.0-19.0 BS 3 17.7997 18.7914 0.9917 18.7646 0.9649 18.7176 0.9179 0.0470 4.87

VI8 0.0-0.5 Not enough sample material

VI8 0.5-1.0 Not enough sample material

VI8 1.0-1.5 Not enough sample material

VI8 3.0-4.0 BS 44 16.9822 17.9867 1.0045 17.9337 0.9515 17.8597 0.8775 0.0740 7.78

VI8 4.0-5.0 BS 61 20.9539 21.9539 1.0000 21.8935 0.9396 21.8119 0.8580 0.0816 8.68 18 VI8 11.5-12.0 (a) 18.2669 19.2676 1.0007 19.2275 0.9606 19.1456 0.8787 0.0819 8.53

VI8 12.0-12.5 39 20.1064 21.1094 1.0030 21.0659 0.9595 20.9677 0.8613 0.0982 10.23

VI8 12.5-13.0 6 18.2218 19.2222 1.0004 19.1793 0.9575 19.0797 0.8579 0.0996 10.40

VI8 13.0-13.5 68 20.8528 21.8586 1.0058 21.8128 0.9600 21.7131 0.8603 0.0997 10.39

74

VI8 13.5-14.0 9 20.8090 21.8064 0.9974 21.7613 0.9523 21.6582 0.8492 0.1031 10.83

VI8 14.0-14.5 43 18.4380 19.4377 0.9997 19.3971 0.9591 19.2997 0.8617 0.0974 10.16

VI8 14.5-15.0 49 20.4075 21.4020 0.9945 21.3566 0.9491 21.2560 0.8485 0.1006 10.60

VI8 15.0-15.5 1 17.9031 18.9061 1.0030 18.8881 0.9850 18.8221 0.9190 0.0660 6.70

VI8 15.5-16.0 45 17.8147 18.8173 1.0026 18.7809 0.9662 18.6948 0.8801 0.0861 8.91

VI8 19.0-20.0 BS 33 21.0927 22.0972 1.0045 22.0550 0.9623 21.9665 0.8738 0.0885 9.20

VI8 20.0-21.0 BS 72 21.0053 22.0035 0.9982 21.9594 0.9541 21.8706 0.8653 0.0888 9.31

CB9 1.1-2.1 BS 35 19.8732 20.8778 1.0046 20.8534 0.9802 20.7938 0.9206 0.0596 6.08

CB9 2.1-3.1 BS 29 21.6753 22.6766 1.0013 22.6458 0.9705 22.5665 0.8912 0.0793 8.17

CB9 18.9-19.9 41 21.1071 22.1026 0.9955 22.0895 0.9824 22.0517 0.9446 0.0378 3.85 18 CB9 19.9-20.9 (b) 20.1275 21.1248 0.9973 21.1068 0.9793 21.0571 0.9296 0.0497 5.08

CB9 20.9-21.9 52 18.2706 19.2767 1.0061 19.2613 0.9907 19.2095 0.9389 0.0518 5.23

CB9 21.9-22.9 12 18.6025 19.6066 1.0041 19.5933 0.9908 19.5422 0.9397 0.0511 5.16

CB9 22.9-23.9 32 21.6010 22.6036 1.0026 22.5893 0.9883 22.5383 0.9373 0.0510 5.16

CB9 23.9-24.9 8 16.6928 17.6953 1.0025 17.6845 0.9917 17.6345 0.9417 0.0500 5.04

CB9 24.9-25.9 20 21.3197 22.3200 1.0003 22.3040 0.9843 22.2545 0.9348 0.0495 5.03

CB9 25.9-26.9 4 20.6923 21.6931 1.0008 21.6798 0.9875 21.6314 0.9391 0.0484 4.90

CB9 26.9-27.9 23 19.1817 20.1812 0.9995 20.1557 0.9740 20.0990 0.9173 0.0567 5.82

CB9 27.9-28.9 26 19.6371 20.6398 1.0027 20.6159 0.9788 20.5501 0.9130 0.0658 6.72

CB9 28.9-29.9 24 21.4584 22.4527 0.9943 22.4257 0.9673 22.3614 0.9030 0.0643 6.65

CB9 29.9-30.9 60 17.5537 18.5529 0.9992 18.5326 0.9789 18.4698 0.9161 0.0628 6.42

CB9 30.9-31.9 38 18.6963 19.6954 0.9991 19.6725 0.9762 19.6096 0.9133 0.0629 6.44 Leaf fragments

CB9 31.9-32.9 57 18.0440 19.0419 0.9979 19.0302 0.9862 18.9831 0.9391 0.0471 4.78

CB9 32.9-33.9 25 19.3763 20.3795 1.0032 20.3674 0.9911 20.3257 0.9494 0.0417 4.21

CB9 33.9-34.9 13 17.1102 18.1153 1.0051 18.1067 0.9965 18.0685 0.9583 0.0382 3.83 Coarse wood + leaf material

CB9 34.9-35.9 64 19.8098 20.8036 0.9938 20.7908 0.9810 20.7595 0.9497 0.0313 3.19 Coarse wood + leaf material

75

RUP02BIS 5.0-6.0 BS 16 20.3331 21.3377 1.0046 21.2881 0.9550 21.2057 0.8726 0.0824 8.63

RUP02BIS 12.0-13.0 BS 54 18.5414 19.5433 1.0019 19.5003 0.9589 19.4167 0.8753 0.0836 8.72

RUP02BIS 14.5-15.5 50 21.0732 22.0745 1.0013 22.0253 0.9521 21.9253 0.8521 0.1000 10.50

RUP02BIS 19.5-20.5 5 20.4288 21.4265 0.9977 21.3872 0.9584 21.2825 0.8537 0.1047 10.92

RUP02BIS 24.5-25.5 66 20.8440 21.8426 0.9986 21.7844 0.9404 21.6422 0.7982 0.1422 15.12

RUP02BIS 29.5-30.5 22 20.7103 21.7197 1.0094 21.6664 0.9561 21.5228 0.8125 0.1436 15.02

RUP02BIS 34.5-35.5 40 17.4615 18.4607 0.9992 18.4070 0.9455 18.2802 0.8187 0.1268 13.41

RUP02BIS 39.5-40.5 65 19.5920 20.5949 1.0029 20.5447 0.9527 20.4146 0.8226 0.1301 13.66

RUP02BIS 44.5-45.5 70 21.5770 22.5739 0.9969 22.5423 0.9653 22.3883 0.8113 0.1540 15.95

RUP02BIS 49.5-50.5 51 20.6904 21.6966 1.0062 21.6569 0.9665 21.4907 0.8003 0.1662 17.20

RUP02BIS 54.5-55.5 75 21.1027 22.1066 1.0039 22.0574 0.9547 21.8977 0.7950 0.1597 16.73

RUP02BIS 59.5-60.5 79 20.6995 21.6985 0.9990 21.6553 0.9558 21.4983 0.7988 0.1570 16.43

RUP02BIS 64.5-65.5 48 16.7092 17.7052 0.9960 17.6658 0.9566 17.5071 0.7979 0.1587 16.59

RUP02BIS 69.5-70.5 73 21.2595 22.2541 0.9946 22.2153 0.9558 22.0557 0.7962 0.1596 16.70

RUP02BIS 74.5-75.5 74 20.7692 21.7618 0.9926 21.7205 0.9513 21.5671 0.7979 0.1534 16.13

RUP02BIS 79.5-80.5 69 20.4485 21.4492 1.0007 21.4121 0.9636 21.2551 0.8066 0.1570 16.29

VI4 0.0-0.5 Not enough sample material

VI4 0.5-1.0 Not enough sample material

VI4 1.0-1.5 Not enough sample material

VI4 3.0-4.0 BS 53 18.7953 19.7922 0.9969 19.7903 0.9950 19.7039 0.9086 0.0864 8.68

VI4 4.0-5.0 BS 44 16.9828 17.9904 1.0076 17.9889 1.0061 17.8911 0.9083 0.0978 9.72

VI4 9.0-9.5 70 21.5769 22.5804 1.0035 22.5773 1.0004 22.4916 0.9147 0.0857 8.57

VI4 9.5-10.0 6 18.2224 19.2263 1.0039 19.2249 1.0025 19.1256 0.9032 0.0993 9.91

VI4 10.0-10.5 30 17.5177 18.5124 0.9947 18.5110 0.9933 18.4095 0.8918 0.1015 10.22

VI4 10.5-11.0 57 18.0446 19.0441 0.9995 19.0395 0.9949 18.9386 0.8940 0.1009 10.14

VI4 19.0-20.0 BS 64 19.8093 20.8059 0.9966 20.8041 0.9948 20.7327 0.9234 0.0714 7.18

VI4 20.0-21.0 BS 74 20.7685 21.7648 0.9963 21.7656 0.9971 21.6843 0.9158 0.0813 8.15

76

RI5 7.5-8.0 49 20.4068 21.4007 0.9939 21.4003 0.9935 21.3057 0.8989 0.0946 9.52

RI5 8.0-8.5 27 20.4964 21.4994 1.0030 21.4956 0.9992 21.4049 0.9085 0.0907 9.08

RI5 8.5-9.0 3 17.8014 18.8047 1.0033 18.8009 0.9995 18.7118 0.9104 0.0891 8.91

RI5 9.0-9.5 21 21.0378 22.0333 0.9955 22.0259 0.9881 21.9343 0.8965 0.0916 9.27

RI5 9.5-10.0 68 20.8530 21.8532 1.0002 21.8414 0.9884 21.7513 0.8983 0.0901 9.12

RI5 10.0-10.5 56 20.6398 21.6382 0.9984 21.6343 0.9945 21.5448 0.9050 0.0895 9.00

RI5 10.5-11.0 36 17.8253 18.8257 1.0004 18.8175 0.9922 18.7204 0.8951 0.0971 9.79

RI5 11.0-11.5 78 18.0552 19.0543 0.9991 19.0464 0.9912 18.9437 0.8885 0.1027 10.36 Wood + leaf fragments

RI5 11.5-12.0 45 17.8161 18.8151 0.9990 18.8126 0.9965 18.7065 0.8904 0.1061 10.65 Wood + leaf fragments

RI5 12.0-12.5 79 20.6997 21.6957 0.9960 21.6873 0.9876 21.5826 0.8829 0.1047 10.60

RI5 12.5-13.0 48 16.7105 17.7202 1.0097 17.7148 1.0043 17.6016 0.8911 0.1132 11.27

RI5 13.0-13.5 14 20.1821 21.1878 1.0057 21.1776 0.9955 21.0578 0.8757 0.1198 12.03

RI5 13.5-14.0 73 21.2598 22.2588 0.9990 22.2511 0.9913 22.1324 0.8726 0.1187 11.97

RI5 14.0-14.5 67 17.7584 18.7520 0.9936 18.7451 0.9867 18.6226 0.8642 0.1225 12.42

RI5 14.5-15.0 5 20.4300 21.4355 1.0055 21.4211 0.9911 21.3058 0.8758 0.1153 11.63

RI5 15.0-15.5 19 20.1591 21.1547 0.9956 21.1444 0.9853 21.0412 0.8821 0.1032 10.47

RI5 17.0-18.0 BS 63 21.0377 22.0385 1.0008 22.0329 0.9952 21.9423 0.9046 0.0906 9.10

RI5 18.0-19.0 BS 37 20.6018 21.6087 1.0069 21.5895 0.9877 21.4987 0.8969 0.0908 9.19

RI7 0.0-0.5 15 21.1919 22.1977 1.0058 22.1783 0.9864 22.0376 0.8457 0.1407 14.26

RI7 0.5-1.0 20 21.3199 22.3120 0.9921 22.2985 0.9786 22.1485 0.8286 0.1500 15.33

RI7 1.0-1.5 76 21.8171 22.8217 1.0046 22.8086 0.9915 22.6415 0.8244 0.1671 16.85

RI7 1.5-2.0 25 19.3765 20.3757 0.9992 20.3668 0.9903 20.1985 0.8220 0.1683 16.99

RI7 2.0-2.5 71 17.9715 18.9721 1.0006 18.9622 0.9907 18.8369 0.8654 0.1253 12.65

RI7 2.5-3.0 33 21.0929 22.0986 1.0057 22.0834 0.9905 22.0057 0.9128 0.0777 7.84

RI7 5.0-6.0 BS 55 17.5675 18.5623 0.9948 18.5498 0.9823 18.4481 0.8806 0.1017 10.35

RI7 6.0-7.0 BS 11 19.7443 20.7422 0.9979 20.7225 0.9782 20.6379 0.8936 0.0846 8.65

RI7 10.5-11.0 77 21.4111 22.4138 1.0027 22.4029 0.9918 22.2756 0.8645 0.1273 12.84

77

RI7 11.0-11.5 47 17.7786 18.7756 0.9970 18.7629 0.9843 18.6407 0.8621 0.1222 12.41

RI7 11.5-12.0 51 20.6900 21.6908 1.0008 21.6739 0.9839 21.5562 0.8662 0.1177 11.96

RI712.0-12.5 52 18.2712 19.2746 1.0034 19.2629 0.9917 19.1358 0.8646 0.1271 12.82

RI7 12.5-13.0 39 20.1059 21.1060 1.0001 21.0875 0.9816 20.9596 0.8537 0.1279 13.03

RI7 13.0-13.5 8 16.6941 17.6991 1.0050 17.6921 0.9980 17.5559 0.8618 0.1362 13.65 Coarse wood + leaf material

RI7 13.5-14.0 9 20.8096 21.8060 0.9964 21.7968 0.9872 21.7238 0.9142 0.0730 7.39 Coarse wood + leaf material

RI7 14.0-14.5 69 20.4483 21.4472 0.9989 21.4387 0.9904 21.3582 0.9099 0.0805 8.13

RI7 15.5-16.5 BS 41 21.1076 22.1024 0.9948 22.0869 0.9793 21.9781 0.8705 0.1088 11.11

RI7 16.5-17.5 BS 34 21.1808 22.1826 1.0018 22.1697 0.9889 22.0665 0.8857 0.1032 10.44

78

2. RESULTS BULK GEOCHEMICAL ANALYSIS

Sample ID δ13C (‰) C Amount δ15N (‰) N Amount Measured TOC (%) TN (%) C/N (µg) (µg) weights (mg) RUP02BIS 5.0-6.0 BS -31.31 1258.95 -0.09 106.51 35.284 3.568 0.302 11.820 RUP02BIS 12.0-13.0 BS -29.65 1149.86 -0.07 90.83 35.401 3.248 0.257 12.659 RUP02BIS 14.5-15.5 -27.05 1135.17 0.89 78.02 30.777 3.688 0.254 14.549 RUP02BIS 19.5-20.5 -26.90 1022.24 0.39 64.27 27.104 3.772 0.237 15.906 RUP02BIS 24.5-25.5 -27.19 1066.73 0.34 68.80 18.200 5.861 0.378 15.504 RUP02BIS 29.5-30.5 -27.02 1076.08 0.30 67.08 18.398 5.849 0.365 16.041 RUP02BIS 34.5-35.5 -27.17 1292.78 0.21 82.34 23.146 5.585 0.356 15.700 RUP02BIS 39.5-40.5 -27.12 1210.34 0.20 76.88 22.530 5.372 0.341 15.743 RUP02BIS 44.5-45.5 -27.23 1026.69 0.15 65.83 18.221 5.635 0.361 15.597 RUP02BIS 49.5-50.5 -27.30 947.33 0.13 62.20 15.197 6.234 0.409 15.230 RUP02BIS 54.5-55.5 -27.25 1044.41 0.18 68.80 16.989 6.148 0.405 15.180 RUP02BIS 59.5-60.5 -27.30 1146.30 0.02 74.08 18.406 6.228 0.402 15.474 RUP02BIS 64.5-65.5 -27.21 999.90 0.09 64.76 16.832 5.940 0.385 15.439 RUP02BIS 69.5-70.5 -27.26 1036.64 0.18 66.95 17.494 5.926 0.383 15.483 RUP02BIS 74.5-75.5 -27.15 974.54 0.09 62.42 16.750 5.818 0.373 15.613 RUP02BIS 79.5-80.5 -27.18 1072.55 0.18 71.26 18.427 5.821 0.387 15.051 RUP04 6.3-7.3 -28.02 1468.79 -1.92 88.14 17.840 8.233 0.494 16.663 RUP04 7.3-8.3 -28.11 1135.31 -1.66 69.16 16.082 7.060 0.430 16.415 RUP04 8.3-9.3 -27.94 1172.44 -1.61 69.96 16.584 7.070 0.422 16.758 RUP04 9.3-10.3 -28.30 1291.32 -1.44 78.33 15.596 8.280 0.502 16.487 RUP04 10.3-11.3 -28.13 1341.84 -1.33 83.33 16.751 8.011 0.497 16.103 RUP04 11.3-12.3 -28.11 1179.46 -1.61 71.99 16.562 7.122 0.435 16.385 RUP04 12.3-13.3 -28.17 1256.86 -1.52 74.64 17.394 7.226 0.429 16.839 RUP04 13.3-14.3 -28.06 1227.91 -1.71 71.71 17.478 7.025 0.410 17.123 RUP04 14.3-15.3 -28.27 1101.62 -1.40 69.18 19.266 5.718 0.359 15.923 RUP04 15.3-16.3 -28.29 1109.30 -1.60 68.91 16.530 6.711 0.417 16.098 RUP04 16.3-17.3 -28.23 1385.58 -1.66 82.02 18.592 7.453 0.441 16.894 RUP04 17.3-18.3 -28.26 1354.65 -1.59 85.45 20.931 6.472 0.408 15.853 RUP04 18.3-19.3 -28.21 1206.71 -0.86 85.31 35.959 3.356 0.237 14.146 RUP04 21.0-22.0 BS -28.86 1196.52 -0.19 99.19 20.886 5.729 0.475 12.063 RUP04 22.0-23.0 BS -28.98 1188.61 -0.34 99.19 23.428 5.073 0.423 11.983 CALA05 0.0-0.5 -29.21 863.63 2.19 109.33 25.913 3.333 0.422 7.899 CALA05 1.0-1.5 -29.98 817.31 2.15 108.11 23.658 3.455 0.457 7.560 CALA05 3.0-4.0 BS -29.77 676.82 2.07 90.51 27.786 2.436 0.326 7.478 CALA05 4.0-5.0 BS -30.12 640.48 2.23 84.66 22.862 2.802 0.370 7.565 CALA05 6.5-7.0 -29.40 794.53 2.15 92.56 19.846 4.003 0.466 8.584 CALA05 7.0-7.5 -29.13 1006.33 1.55 116.44 37.173 2.707 0.313 8.643 CALA05 7.5-8.0 -28.85 1041.68 1.45 128.41 39.081 2.665 0.329 8.112 CALA05 8.0-8.5 -29.01 771.17 1.33 93.99 28.332 2.722 0.332 8.204 CALA05 8.5-9.0 -29.01 825.05 1.46 102.65 30.721 2.686 0.334 8.038 CALA05 9.0-9.5 -29.10 889.65 1.21 100.49 30.729 2.895 0.327 8.853 CALA05 9.5-10.0 -29.16 1000.15 0.64 124.51 34.129 2.930 0.365 8.032 CALA05 10.0-10.5 -29.05 1040.94 1.15 113.21 34.715 2.999 0.326 9.195 CALA05 10.5-11.0 -29.33 821.99 1.74 95.51 42.545 1.932 0.224 8.606 CALA05 13.0-14.0 BS -29.93 723.70 1.61 89.36 21.937 3.299 0.407 8.099 CALA05 14.0-15.0 BS -30.42 758.28 1.10 94.68 24.680 3.072 0.384 8.009 CB9 1.1-2.1 BS -31.07 678.34 1.80 74.53 23.135 2.932 0.322 9.101 CB9 2.1-3.1 BS -29.12 967.29 1.84 100.41 41.424 2.335 0.242 9.634 CB9 18.9-19.9 -29.41 364.75 1.77 44.61 39.421 0.925 0.113 8.177 CB9 19.9-20.9 -28.79 415.39 1.08 41.30 29.437 1.411 0.140 10.057

79

CB9 20.9-21.9 -28.74 514.04 1.48 52.70 35.019 1.468 0.150 9.754 CB9 21.9-22.9 -28.60 579.29 1.20 53.05 35.635 1.626 0.149 10.919 CB9 22.9-23.9 -28.66 659.76 1.51 64.92 41.354 1.595 0.157 10.163 CB9 23.9-24.9 -28.65 677.34 1.43 63.84 42.541 1.592 0.150 10.610 CB9 24.9-25.9 -28.74 689.05 1.37 63.17 41.659 1.654 0.152 10.908 CB9 25.9-26.9 -28.85 717.50 1.40 73.49 50.997 1.407 0.144 9.763 CB9 26.9-27.9 -29.08 621.78 1.40 69.54 32.230 1.929 0.216 8.941 CB9 27.9-28.9 -29.07 683.19 1.50 76.20 33.449 2.042 0.228 8.966 CB9 28.9-29.9 -28.94 691.11 1.53 73.37 30.236 2.286 0.243 9.420 CB9 29.9-30.9 -29.12 717.45 1.72 79.96 34.413 2.085 0.232 8.972 CB9 30.9-31.9 -28.93 1025.78 1.22 110.15 53.938 1.902 0.204 9.312 CB9 31.9-32.9 -28.90 820.16 1.38 82.35 62.556 1.311 0.132 9.959 CB9 32.9-33.9 -28.73 1090.26 1.08 98.52 62.951 1.732 0.157 11.066 CB9 33.9-34.9 -28.70 446.18 3.22 45.73 61.903 0.721 0.074 9.757 CB9 34.9-35.9 -28.80 499.83 1.31 49.69 60.505 0.826 0.082 10.059 CGC1 21.1-21.6 -27.98 240.91 1.48 20.70 59.430 0.405 0.035 11.640 CGC1 21.6-22.1 -28.06 176.52 2.60 13.91 61.739 0.286 0.023 12.693 CGC1 22.1-22.6 -27.93 188.85 2.45 22.53 59.915 0.315 0.038 8.383 CGC1 22.6-23.1 -28.02 257.79 2.30 19.56 61.346 0.420 0.032 13.177 CGC1 23.1-23.6 -28.38 348.08 1.11 25.29 59.332 0.587 0.043 13.766 CGC1 23.6-24.1 -28.13 246.35 2.15 18.62 64.843 0.380 0.029 13.230 CGC1 24.1-24.6 -28.11 270.95 1.55 24.64 63.595 0.426 0.039 10.996 CGC1 24.6-25.0 -28.14 279.57 2.20 19.92 61.530 0.454 0.032 14.037 CGC1 2.0-3.0 BS -29.20 1069.01 1.20 97.43 43.109 2.480 0.226 10.973 CGC1 3.0-4.0 BS -29.21 1126.68 1.50 104.29 36.767 3.064 0.284 10.803 RI8 8.7-9.2 -28.54 1016.39 1.77 99.16 32.261 3.151 0.307 10.250 RI8 9.2-9.7 -28.62 1121.80 1.79 105.83 32.540 3.447 0.325 10.601 RI8 9.7-10.2 -28.63 1085.71 1.86 102.61 31.521 3.444 0.326 10.581 RI8 10.2-10.7 -28.60 1024.64 1.76 100.09 30.441 3.366 0.329 10.237 RI8 10.7-11.2 -28.64 1075.82 1.70 103.81 32.138 3.348 0.323 10.364 RI8 11.7-12.2 -28.68 1172.14 1.65 112.02 35.306 3.320 0.317 10.464 RI8 12.2-12.7 -28.65 1210.88 1.88 114.08 36.019 3.362 0.317 10.614 RI8 12.7-13.2 -28.57 1112.93 1.87 101.80 31.803 3.499 0.320 10.932 RI8 13.2-13.7 -28.39 1307.61 1.38 106.25 32.962 3.967 0.322 12.307 RI8 13.7-14.2 -28.50 1042.51 1.26 78.43 24.675 4.225 0.318 13.292 RI8 14.2-14.7 -28.24 1406.02 0.05 94.79 26.391 5.328 0.359 14.832 RI8 14.7-14.9 -27.90 985.91 1.25 57.77 36.908 2.671 0.157 17.067 RI8 16.0-17.0 BS -29.12 1049.11 1.60 100.33 31.112 3.372 0.322 10.456 RI8 22.0-23.0 BS -30.01 872.43 0.60 86.96 38.655 2.257 0.225 10.033 CALA08 0.5-1.5 -28.37 1128.22 1.36 97.93 54.664 2.064 0.179 11.521 CALA08 1.5-2.5 -28.18 1232.72 1.37 99.99 54.695 2.254 0.183 12.329 CALA08 2.5-3.5 -28.16 1147.97 1.33 90.78 50.423 2.277 0.180 12.646 CALA08 3.5-4.5 -28.34 1257.45 1.42 100.46 53.542 2.349 0.188 12.516 CALA08 4.5-5.5 -28.22 1064.18 1.76 86.50 45.925 2.317 0.188 12.302 CALA08 5.5-6.5 -28.32 1197.30 1.21 96.22 47.165 2.539 0.204 12.444 CALA08 6.5-7.5 -28.32 1189.06 1.63 94.34 46.088 2.580 0.205 12.604 CALA08 7.5-8.5 -28.58 1097.71 1.44 90.96 44.636 2.459 0.204 12.068 CALA08 8.5-9.5 -28.57 1306.17 1.29 107.94 59.555 2.193 0.181 12.101 CALA08 9.5-10.5 -28.55 1206.41 1.49 99.72 57.892 2.084 0.172 12.098 CALA08 10.5-11.5 -28.71 1231.56 1.67 101.90 52.517 2.345 0.194 12.086 CALA08 11.5-12.0 -28.96 1041.05 1.74 91.15 60.775 1.713 0.150 11.422 CALA08 14.0-15.0 BS -29.80 709.78 1.15 79.70 24.557 2.890 0.325 8.905 CALA08 15.0-16.0 BS -30.15 917.18 1.61 105.74 29.430 3.116 0.359 8.674 CB4 1.2-2.2 BS -29.57 919.88 1.72 92.42 29.947 3.072 0.309 9.954

80

CB4 2.2-3.2 BS -28.70 1077.87 1.75 102.98 34.918 3.087 0.295 10.467 CB4 14.8-15.3 -28.61 876.30 1.30 81.00 60.308 1.453 0.134 10.818 CB4 15.8-16.3 -28.33 1096.61 0.97 88.00 59.736 1.836 0.147 12.461 CB4 16.3-16.8 -28.51 1040.42 0.84 83.21 51.568 2.018 0.161 12.504 CB4 16.8-17.3 -28.59 1320.55 0.90 109.75 62.113 2.126 0.177 12.032 CB4 17.3-17.8 -28.57 1226.02 0.83 101.87 59.082 2.075 0.172 12.035 CB4 17.8-18.3 -28.55 1024.94 1.16 83.44 46.946 2.183 0.178 12.283 CB4 18.3-18.8 -28.53 1058.04 0.98 89.70 49.819 2.124 0.180 11.795 CB4 18.8-19.3 -28.30 1220.18 0.84 96.18 47.030 2.594 0.204 12.687 CB4 19.3-19.8 -28.95 1739.75 0.15 102.16 42.663 4.078 0.239 17.029 CB4 19.8-20.3 -28.44 1209.12 0.03 82.11 33.684 3.590 0.244 14.725 CB4 20.3-20.8 -28.10 1167.84 0.34 92.30 61.707 1.893 0.150 12.653 CB4 20.8-21.3 -28.79 1042.08 0.95 84.74 55.231 1.887 0.153 12.297 VI18 0.0-0.5 -29.94 1181.66 1.09 126.85 39.238 3.012 0.323 9.315 VI18 0.5-1.0 -28.40 661.01 0.76 57.99 27.240 2.427 0.213 11.400 VI18 1.0-1.5 -28.01 904.42 0.77 67.89 34.154 2.648 0.199 13.321 VI18 1.5-2.0 -27.91 1486.10 0.74 107.00 57.059 2.604 0.188 13.889 VI18 2.0-2.5 -27.93 1407.53 0.89 104.38 54.266 2.594 0.192 13.484 VI18 2.5-3.0 -27.95 1386.95 1.58 131.12 51.054 2.717 0.257 10.578 VI18 3.0-3.5 -27.99 1264.62 1.72 110.48 39.925 3.167 0.277 11.446 VI18 3.5-4.0 -27.96 1031.91 1.95 91.62 31.783 3.247 0.288 11.262 VI18 4.0-4.5 -28.05 1370.11 2.08 120.51 42.151 3.250 0.286 11.369 VI18 4.5-5.0 -27.94 1018.75 1.80 87.13 34.659 2.939 0.251 11.692 VI18 5.0-5.5 -28.25 816.42 1.96 74.71 63.502 1.286 0.118 10.928 VI18 7.0-8.0 BS -28.07 1052.97 1.56 109.91 31.747 3.317 0.346 9.580 VI18 8.0-9.0 BS -28.25 849.94 1.32 83.41 24.288 3.499 0.343 10.190 RUP03TRIS 5.5-6.0 -28.85 633.39 0.77 66.48 23.554 2.689 0.282 9.528 RUP03TRIS 6.0-6.5 -28.63 571.44 0.56 61.24 22.459 2.544 0.273 9.331 RUP03TRIS 6.5-7.0 -28.68 557.96 0.76 58.88 21.406 2.607 0.275 9.476 RUP03TRIS 7.0-7.5 -28.81 598.25 0.34 62.53 21.950 2.726 0.285 9.567 RUP03TRIS 7.5-8.0 -28.75 705.77 0.25 73.84 24.935 2.830 0.296 9.558 RUP03TRIS 8.0-8.5 -28.90 811.55 0.28 77.73 25.357 3.201 0.307 10.441 RUP03TRIS 8.5-9.0 -28.86 805.88 0.22 78.64 26.508 3.040 0.297 10.247 RUP03TRIS 9.0-9.5 -28.67 738.18 0.46 75.02 25.254 2.923 0.297 9.840 RUP03TRIS 10.0-10.5 -28.79 979.16 0.36 87.25 29.064 3.369 0.300 11.222 RUP03TRIS 10.5-11.0 -28.85 788.42 0.35 77.51 24.571 3.209 0.315 10.172 RUP03TRIS 11.0-11.5 -28.73 727.65 0.27 75.50 24.507 2.969 0.308 9.637 RUP03TRIS 12.0-12.5 -28.79 791.69 0.31 79.55 26.215 3.020 0.303 9.953 RUP03TRIS 12.5-13.0 -28.85 798.29 0.29 85.11 27.133 2.942 0.314 9.380 RUP03TRIS 13.0-13.5 -28.90 899.52 0.17 89.80 30.986 2.903 0.290 10.017 RUP03TRIS 13.5-14.0 -28.67 833.16 0.13 83.20 27.699 3.008 0.300 10.014 RUP03TRIS 14.0-14.5 -28.85 767.02 0.27 78.21 26.946 2.847 0.290 9.808 RUP03TRIS 15.0-15.5 -28.93 770.02 0.79 75.09 23.359 3.296 0.321 10.254 RUP03TRIS 17.0-18.0 BS -29.40 712.13 0.28 77.85 24.851 2.866 0.313 9.148 RUP03TRIS 18.0-19.0 BS -29.43 691.20 -0.37 75.91 41.447 1.668 0.183 9.105 VI8 0.0-0.5 -29.72 675.70 2.69 82.31 17.695 3.819 0.465 8.209 VI8 0.5-1.0 -28.98 634.47 2.51 75.17 16.505 3.844 0.455 8.440 VI8 1.0-1.5 -29.12 729.92 2.69 85.39 17.311 4.217 0.493 8.548 VI8 3.0-4.0 BS -28.12 717.79 2.10 86.29 23.358 3.073 0.369 8.318 VI8 4.0-5.0 BS -28.25 992.22 2.34 111.65 29.638 3.348 0.377 8.887 VI8 11.5-12.0 -27.54 1316.05 1.75 108.31 32.574 4.040 0.333 12.150 VI8 12.0-12.5 -27.41 1460.49 1.64 112.94 31.496 4.637 0.359 12.931 VI8 12.5-13.0 -27.33 1487.62 1.77 116.81 30.590 4.863 0.382 12.735 VI8 13.0-13.5 -27.43 1377.74 1.58 112.00 29.914 4.606 0.374 12.301

81

VI8 13.5-14.0 -27.69 1470.33 1.65 117.79 30.541 4.814 0.386 12.482 VI8 14.0-14.5 -27.49 1778.83 1.43 119.14 29.676 5.994 0.401 14.930 VI8 14.5-15.0 -27.38 1488.41 1.64 103.39 28.253 5.268 0.366 14.396 VI8 15.0-15.5 -27.53 1105.53 2.30 103.55 55.702 1.985 0.186 10.676 VI8 15.5-16.0 -27.68 1059.30 2.65 107.66 33.176 3.193 0.325 9.840 VI8 19.0-20.0 BS -28.10 1003.45 2.38 105.04 32.155 3.121 0.327 9.553 VI8 20.0-21.0 BS -28.29 696.46 2.05 72.83 21.374 3.258 0.341 9.562 VI4 0.0-0.5 -29.02 746.88 2.73 80.11 16.466 4.536 0.486 9.324 VI4 0.5-1.0 -28.42 646.06 2.51 73.43 15.858 4.074 0.463 8.799 VI4 1.0-1.5 -28.52 886.55 2.84 91.39 20.349 4.357 0.449 9.701 VI4 3.0-4.0 BS -27.76 915.31 2.49 99.09 26.534 3.450 0.373 9.237 VI4 4.0-5.0 BS -28.25 1184.27 2.33 121.10 30.599 3.870 0.396 9.779 VI4 9.0-9.5 -27.38 1016.21 2.67 101.25 31.177 3.259 0.325 10.037 VI4 9.5-10.0 -27.26 1178.35 2.60 106.41 31.571 3.732 0.337 11.074 VI4 10.0-10.5 -27.15 1316.53 2.40 111.36 32.067 4.106 0.347 11.822 VI4 10.5-11.0 -27.21 1165.17 2.35 104.35 29.592 3.937 0.353 11.166 VI4 19.0-20.0 BS -27.79 1078.53 2.08 115.59 38.735 2.784 0.298 9.330 VI4 20.0-21.0 BS -27.77 897.38 1.98 98.31 30.617 2.931 0.321 9.128 RI5 7.5-8.0 -28.38 1154.49 1.20 97.03 30.613 3.771 0.317 11.898 RI5 8.0-8.5 -28.54 1195.53 1.26 112.03 35.026 3.413 0.320 10.671 RI5 8.5-9.0 -28.52 1174.52 1.23 110.09 34.136 3.441 0.323 10.669 RI5 9.0-9.5 -28.57 1087.90 1.20 102.70 32.401 3.358 0.317 10.593 RI5 9.5-10.0 -28.62 1117.99 1.26 104.37 32.336 3.457 0.323 10.712 RI5 10.0-10.5 -28.59 1169.27 1.28 109.33 32.561 3.591 0.336 10.695 RI5 10.5-11.0 -28.67 1133.13 1.38 103.22 31.103 3.643 0.332 10.977 RI5 11.0-11.5 -28.57 1103.92 1.23 97.85 29.064 3.798 0.337 11.282 RI5 11.5-12.0 -28.42 1103.57 1.12 93.85 27.503 4.013 0.341 11.759 RI5 12.0-12.5 -28.53 1181.25 1.11 101.83 30.304 3.898 0.336 11.600 RI5 12.5-13.0 -28.20 1468.29 0.91 103.16 28.773 5.103 0.359 14.233 RI5 13.0-13.5 -28.24 1361.25 0.75 93.25 26.550 5.127 0.351 14.597 RI5 13.5-14.0 -28.17 1276.58 0.65 90.83 23.993 5.321 0.379 14.054 RI5 14.0-14.5 -28.31 1122.78 1.03 82.91 22.828 4.918 0.363 13.543 RI5 14.5-15.0 -28.30 1271.63 1.08 98.57 27.622 4.604 0.357 12.901 RI5 15.0-15.5 -28.48 1238.19 1.31 103.03 29.110 4.253 0.354 12.018 RI5 17.0-18.0 BS -28.92 1225.17 1.38 118.48 33.133 3.698 0.358 10.341 RI5 18.0-19.0 BS -29.04 1349.42 0.92 120.40 32.690 4.128 0.368 11.207 RI7 0.0-0.5 -28.77 1250.96 1.63 90.37 20.069 6.233 0.450 13.843 RI7 0.5-1.0 -28.75 1488.06 1.22 98.07 18.029 8.254 0.544 15.174 RI7 1.0-1.5 -28.57 1084.70 1.12 73.23 15.612 6.948 0.469 14.811 RI7 1.5-2.0 -28.60 1174.58 1.00 74.42 16.168 7.265 0.460 15.783 RI7 2.0-2.5 -28.50 1711.24 0.49 103.44 24.072 7.109 0.430 16.544 RI7 2.5-3.0 -29.15 1066.92 2.21 94.23 29.314 3.640 0.321 11.323 RI7 5.0-6.0 BS -29.45 1126.77 1.83 118.16 28.148 4.003 0.420 9.536 RI7 6.0-7.0 BS -29.78 789.07 1.60 81.25 22.268 3.544 0.365 9.712 RI7 10.5-11.0 -28.13 1113.50 1.01 70.88 21.203 5.252 0.334 15.710 RI7 11.0-11.5 -28.12 1259.69 0.97 84.18 25.297 4.980 0.333 14.964 RI7 11.5-12.0 -28.20 1209.11 1.11 79.75 27.163 4.451 0.294 15.160 RI7 12.0-12.5 -28.25 1210.10 0.78 80.26 22.556 5.365 0.356 15.077 RI7 12.5-13.0 -28.09 937.12 0.97 57.61 21.736 4.311 0.265 16.268 RI7 13.0-13.5 -28.10 1184.17 0.48 65.60 21.151 5.599 0.310 18.051 RI7 13.5-14.0 -27.69 2277.95 0.35 87.18 43.150 5.279 0.202 26.130 RI7 14.0-14.5 -27.76 1955.47 0.57 96.58 41.342 4.730 0.234 20.246 RI7 15.5-16.5 BS -28.69 1124.71 1.80 97.02 25.167 4.469 0.386 11.593

82

3. RESULTS GRAIN SIZE ANALYSIS

Sample name Sample type Textural group Sediment name Mean (µm) Sorting Skewness Kurtosis

CALA05 0.0-0.5 Polymodal, Very Poorly Sorted Mud Fine Silt 7.066 4.054 0.111 0.892 CALA05 1.0-1.5 Trimodal, Very Poorly Sorted Mud Very Fine Silt 6.113 4.088 0.189 1.059 CALA05 3.0-4.0 BS Unimodal, Poorly Sorted Mud Very Fine Silt 5.198 3.191 0.140 1.026 CALA05 4.0-5.0 BS Unimodal, Poorly Sorted Mud Fine Silt 5.304 3.210 0.101 1.013 CALA05 6.5-7.0 Trimodal, Very Poorly Sorted Mud Very Fine Silt 4.075 4.388 0.088 1.008 CALA05 7.0-7.5 Polymodal, Very Poorly Sorted Mud Very Fine Silt 7.207 4.421 0.072 0.861 CALA05 7.5-8.0 Polymodal, Very Poorly Sorted Mud Fine Silt 9.210 4.295 0.004 0.789 CALA05 8.0-8.5 Polymodal, Very Poorly Sorted Mud Very Fine Silt 8.149 4.250 0.059 0.810 CALA05 8.5-9.0 Trimodal, Poorly Sorted Mud Fine Silt 10.11 3.927 0.041 0.757 CALA05 9.0-9.5 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Fine Silt 9.250 4.747 0.048 0.764 CALA05 9.5-10.0 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Fine Silt 10.16 5.180 0.034 0.772 CALA05 10.0-10.5 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Fine Silt 10.86 5.103 0.015 0.779 CALA05 10.5-11.0 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 31.81 5.725 -0.447 0.746 CALA05 13.0-14.0 BS Trimodal, Poorly Sorted Mud Very Fine Silt 5.682 3.694 0.153 1.010 CALA05 14.0-15.0 BS Trimodal, Poorly Sorted Mud Very Fine Silt 4.258 3.644 0.125 1.091 CALA08 0.5-1.5 Trimodal, Poorly Sorted Mud Medium Silt 8.833 2.923 -0.061 0.902 CALA08 1.5-2.5 Trimodal, Poorly Sorted Mud Coarse Silt 10.81 2.836 -0.143 0.944 CALA08 2.5-3.5 Trimodal, Poorly Sorted Mud Coarse Silt 11.87 2.829 -0.155 0.979 CALA08 3.5-4.5 Trimodal, Poorly Sorted Mud Coarse Silt 11.98 2.781 -0.166 0.995 CALA08 4.5-5.5 Trimodal, Poorly Sorted Mud Coarse Silt 12.11 2.741 -0.178 0.999 CALA08 5.5-6.5 Trimodal, Poorly Sorted Mud Coarse Silt 11.36 2.748 -0.181 0.995 CALA08 6.5-7.5 Trimodal, Poorly Sorted Mud Coarse Silt 11.24 2.738 -0.184 0.995 CALA08 7.5-8.5 Bimodal, Poorly Sorted Mud Coarse Silt 13.24 2.870 -0.180 1.032 CALA08 8.5-9.5 Bimodal, Poorly Sorted Mud Coarse Silt 16.71 2.946 -0.228 1.011 CALA08 9.5-10.5 Bimodal, Poorly Sorted Sandy Mud Very Fine Sandy Coarse Silt 18.94 3.050 -0.216 1.000 CALA08 10.5-11.5 Trimodal, Poorly Sorted Mud Coarse Silt 16.93 3.044 -0.191 0.997

83

CALA08 11.5-12.0 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 24.17 2.769 -0.284 1.069 CALA08 14.0-15.0 BS Bimodal, Poorly Sorted Mud Fine Silt 6.325 3.122 0.008 0.956 CALA08 15.0-16.0 BS Unimodal, Poorly Sorted Mud Fine Silt 5.443 3.083 0.033 1.012 CB4 1.2-2.2 BS Bimodal, Poorly Sorted Mud Medium Silt 7.895 2.913 -0.091 0.961 CB4 2.2-3.2 BS Bimodal, Poorly Sorted Mud Medium Silt 7.430 3.075 -0.079 0.997 CB4 14.8-15.3 Unimodal, Poorly Sorted Mud Fine Silt 4.708 3.024 0.057 1.067 CB4 15.3-15.8 Trimodal, Poorly Sorted Mud Medium Silt 11.29 2.949 -0.119 0.976 CB4 15.8-16.3 Trimodal, Poorly Sorted Mud Medium Silt 11.85 3.024 -0.130 0.972 CB4 16.3-16.8 Trimodal, Poorly Sorted Mud Medium Silt 12.58 3.377 -0.046 0.991 CB4 16.8-17.3 Bimodal, Poorly Sorted Mud Medium Silt 10.88 3.173 -0.038 1.000 CB4 17.3-17.8 Bimodal, Poorly Sorted Mud Medium Silt 10.72 3.240 -0.024 1.011 CB4 17.8-18.3 Trimodal, Poorly Sorted Sandy Mud Very Fine Sandy Medium Silt 12.67 3.838 0.059 1.075 CB4 18.3-18.8 Bimodal, Poorly Sorted Mud Medium Silt 10.84 3.187 -0.019 1.033 CB4 18.8-19.3 Bimodal, Poorly Sorted Mud Medium Silt 11.53 3.491 0.007 1.058 CB4 19.3-19.8 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Medium Silt 15.73 4.406 0.098 0.985 CB4 19.8-20.3 Bimodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Medium Silt 15.39 4.067 0.043 0.925 CB4 20.3-20.8 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 33.63 5.419 -0.137 0.847 CB4 20.8-21.3 Polymodal, Very Poorly Sorted Muddy Sand Very Coarse Silty Very Fine Sand 49.62 5.857 -0.209 0.854 CB9 1.1-2.1 BS Trimodal, Poorly Sorted Mud Fine Silt 6.973 3.059 -0.022 0.903 CB9 2.1-3.1 BS Polymodal, Very Poorly Sorted Sandy Mud Fine Sandy Medium Silt 10.18 4.198 0.111 1.073 CB9 18.9-19.9 Bimodal, Poorly Sorted Mud Very Fine Silt 6.143 3.700 0.267 1.057 CB9 19.9-20.9 Bimodal, Poorly Sorted Mud Fine Silt 8.845 2.987 0.028 0.919 CB9 20.9-21.9 Polymodal, Poorly Sorted Mud Medium Silt 9.945 3.066 -0.028 0.918 CB9 21.9-22.9 Trimodal, Poorly Sorted Mud Medium Silt 10.29 3.003 -0.069 0.928 CB9 22.9-23.9 Trimodal, Poorly Sorted Mud Medium Silt 10.67 3.013 -0.105 0.949 CB9 23.9-24.9 Trimodal, Poorly Sorted Mud Coarse Silt 11.61 2.953 -0.161 0.941 CB9 24.9-25.9 Trimodal, Poorly Sorted Mud Coarse Silt 11.33 3.027 -0.153 0.950 CB9 25.9-26.9 Bimodal, Poorly Sorted Mud Coarse Silt 13.80 3.166 -0.236 0.925 CB9 26.9-27.9 Polymodal, Very Poorly Sorted Sandy Mud Fine Sandy Coarse Silt 18.32 5.029 -0.021 0.860 CB9 27.9-28.9 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Fine Silt 12.63 4.856 0.055 0.909

84

CB9 28.9-29.9 Polymodal, Poorly Sorted Mud Fine Silt 8.467 3.750 0.013 0.880 CB9 29.9-30.9 Polymodal, Poorly Sorted Mud Fine Silt 10.15 3.983 -0.002 0.837 CB9 30.9-31.9 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 13.34 4.452 -0.100 0.775 CB9 31.9-32.9 Polymodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 32.23 3.977 -0.462 1.091 CB9 32.9-33.9 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 37.37 4.094 -0.484 1.123 CB9 33.9-34.9 Bimodal, Poorly Sorted Muddy Sand Very Coarse Silty Very Fine Sand 51.44 3.420 -0.436 1.437 CB9 34.9-35.9 Trimodal, Poorly Sorted Muddy Sand Very Coarse Silty Very Fine Sand 55.40 3.659 -0.413 1.352 CGC1 2.0-3.0 BS Bimodal, Poorly Sorted Mud Medium Silt 8.557 2.968 -0.033 0.974 CGC1 3.0-4.0 BS Trimodal, Poorly Sorted Mud Medium Silt 10.68 3.577 0.039 1.139 CGC1 21.1-21.6 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 39.36 2.264 -0.214 1.147 CGC1 21.6-22.1 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 44.13 2.208 -0.228 1.149 CGC1 22.6-23.1 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 48.84 2.220 -0.262 1.207 CGC1 23.1-23.6 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 52.84 2.166 -0.257 1.243 CGC1 23.6-24.1 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 47.84 2.214 -0.286 1.285 CGC1 24.1-24.6 Unimodal, Poorly Sorted Muddy Sand Very Coarse Silty Very Fine Sand 57.65 2.299 -0.335 1.392 CGC1 24.6-25.0 Unimodal, Poorly Sorted Muddy Sand Very Coarse Silty Very Fine Sand 64.57 2.372 -0.318 1.388 RI5 7.5-8.0 Polymodal, Very Poorly Sorted Mud Very Fine Silt 8.369 4.109 0.079 0.796 RI5 8.0-8.5 Trimodal, Poorly Sorted Mud Very Fine Silt 7.451 3.712 0.150 0.830 RI5 8.5-9.0 Polymodal, Poorly Sorted Mud Very Fine Silt 6.584 3.795 0.128 0.855 RI5 9.0-9.5 Polymodal, Poorly Sorted Mud Very Fine Silt 7.060 3.978 0.113 0.841 RI5 9.5-10.0 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Fine Silt 11.43 5.185 0.129 0.826 RI5 10.0-10.5 Polymodal, Poorly Sorted Mud Fine Silt 8.098 3.897 0.117 0.844 RI5 10.5-11.0 Polymodal, Very Poorly Sorted Mud Fine Silt 8.517 4.107 0.073 0.819 RI5 11.0-11.5 Polymodal, Very Poorly Sorted Mud Fine Silt 9.367 4.252 0.059 0.800 RI5 11.5-12.0 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Fine Silt 9.403 4.273 0.056 0.803 RI5 12.0-12.5 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Fine Silt 10.26 4.104 0.016 0.781 RI5 12.5-13.0 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 15.81 4.443 -0.196 0.783 RI5 13.0-13.5 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 23.75 3.729 -0.355 0.960 RI5 13.5-14.0 Bimodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 22.67 4.169 -0.302 0.898 RI5 14.0-14.5 Trimodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 18.79 4.162 -0.282 0.834

85

RI5 14.5-15.0 Bimodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 23.41 4.003 -0.305 0.892 RI5 15.0-15.5 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 15.21 4.611 -0.154 0.766 RI5 17.0-18.0 BS Bimodal, Poorly Sorted Mud Fine Silt 6.535 3.359 0.105 0.924 RI5 18.0-19.0 BS Trimodal, Poorly Sorted Mud Fine Silt 6.876 3.618 0.098 0.899 RI7 0.0-0.5 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 25.26 3.981 -0.337 0.932 RI7 0.5-1.0 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 19.76 4.320 -0.261 0.834 RI7 1.0-1.5 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 21.09 4.571 -0.291 0.824 RI7 1.5-2.0 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 25.93 4.523 -0.321 0.866 RI7 2.0-2.5 Bimodal, Poorly Sorted Muddy Sand Very Coarse Silty Very Fine Sand 50.35 3.741 -0.382 1.114 RI7 2.5-3.0 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 31.80 4.979 -0.432 0.836 RI7 5.0-6.0 BS Bimodal, Poorly Sorted Mud Fine Silt 6.698 3.598 0.188 0.951 RI7 6.0-7.0 BS Polymodal, Poorly Sorted Mud Fine Silt 5.680 3.331 0.091 0.943 RI7 10.5-11.0 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 27.67 3.490 -0.311 1.026 RI7 11.0-11.5 Trimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 23.36 3.958 -0.320 0.946 RI7 11.5-12.0 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 26.87 3.698 -0.299 1.075 RI7 12.0-12.5 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 27.65 3.758 -0.307 1.022 RI7 12.5-13.0 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 27.65 3.889 -0.303 1.016 RI7 13.0-13.5 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 45.33 3.476 -0.248 1.143 RI7 13.5-14.0 Unimodal, Poorly Sorted Muddy Sand Very Coarse Silty Very Fine Sand 64.40 2.956 -0.199 1.183 RI7 14.0-14.5 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 50.42 3.439 -0.279 1.128 RI7 15.5-16.5 BS Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Fine Silt 10.62 4.126 0.064 0.829 RI7 16.5-17.5 BS Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 13.93 4.062 -0.167 0.780 RI8 8.7-9.2 Trimodal, Poorly Sorted Mud Very Fine Silt 6.700 3.511 0.108 0.845 RI8 9.2-9.7 Polymodal, Poorly Sorted Mud Very Fine Silt 6.421 3.756 0.114 0.872 RI8 9.7-10.2 Polymodal, Poorly Sorted Mud Very Fine Silt 6.670 3.684 0.087 0.883 RI8 10.2-10.7 Trimodal, Poorly Sorted Mud Fine Silt 6.891 3.631 0.097 0.879 RI8 10.7-11.2 Polymodal, Poorly Sorted Mud Very Fine Silt 6.731 3.738 0.086 0.886 RI8 11.7-12.2 Polymodal, Very Poorly Sorted Mud Very Fine Silt 7.002 4.079 0.123 0.901 RI8 12.2-12.7 Polymodal, Very Poorly Sorted Mud Very Fine Silt 8.087 4.224 0.106 0.861 RI8 12.7-13.2 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Fine Silt 10.52 4.385 0.061 0.788

86

RI8 13.2-13.7 Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 12.43 4.721 -0.037 0.735 RI8 14.2-14.7 Bimodal, Very Poorly Sorted Muddy Sand Very Coarse Silty Very Fine Sand 44.69 4.029 -0.406 1.179 RI8 14.7-14.9 Trimodal, Poorly Sorted Muddy Sand Very Coarse Silty Very Fine Sand 73.46 3.208 -0.385 1.315 RI8 16.0-17.0 BS Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Fine Silt 8.051 4.347 0.193 0.981 RI8 22.0-23.0 BS Trimodal, Poorly Sorted Mud Very Fine Silt 3.894 3.241 0.120 1.275 RUP02BIS 5.0-6.0 BS Bimodal, Poorly Sorted Mud Medium Silt 9.921 3.044 -0.093 0.971 RUP02BIS 12.0-13.0 BS Bimodal, Poorly Sorted Mud Medium Silt 9.854 3.001 -0.041 0.983 RUP02BIS 14.5-15.5 Trimodal, Poorly Sorted Mud Fine Silt 6.862 3.055 -0.019 0.948 RUP02BIS 19.5-20.5 Trimodal, Poorly Sorted Mud Medium Silt 12.19 3.190 -0.080 0.960 RUP02BIS 24.5-25.5 Bimodal, Poorly Sorted Mud Medium Silt 8.079 2.755 -0.100 0.977 RUP02BIS 29.5-30.5 Bimodal, Poorly Sorted Mud Medium Silt 8.390 2.689 -0.125 0.980 RUP02BIS 34.5-35.5 Bimodal, Poorly Sorted Mud Medium Silt 9.322 2.880 -0.101 1.008 RUP02BIS 39.5-40.5 Bimodal, Poorly Sorted Mud Medium Silt 9.958 2.984 -0.095 0.994 RUP02BIS 44.5-45.5 Bimodal, Poorly Sorted Mud Medium Silt 9.016 2.859 -0.113 0.994 RUP02BIS 49.5-50.5 Bimodal, Poorly Sorted Mud Medium Silt 8.016 2.749 -0.128 0.983 RUP02BIS 54.5-55.5 Bimodal, Poorly Sorted Mud Medium Silt 8.193 2.796 -0.117 0.998 RUP02BIS 59.5-60.5 Bimodal, Poorly Sorted Mud Medium Silt 8.346 2.833 -0.103 1.020 RUP02BIS 64.5-65.5 Bimodal, Poorly Sorted Mud Medium Silt 7.885 2.693 -0.155 0.965 RUP02BIS 69.5-70.5 Bimodal, Poorly Sorted Mud Medium Silt 8.412 2.771 -0.125 0.990 RUP02BIS 74.5-75.5 Bimodal, Poorly Sorted Mud Medium Silt 8.859 2.807 -0.129 0.986 RUP02BIS 79.5-80.5 Bimodal, Poorly Sorted Mud Medium Silt 8.784 2.811 -0.128 0.997 RUP03TRIS 10.5-11.0 Bimodal, Poorly Sorted Mud Medium Silt 10.19 3.532 0.036 0.937 RUP03TRIS 11.0-11.5 Trimodal, Poorly Sorted Mud Fine Silt 8.149 3.373 0.036 0.968 RUP03TRIS 12.0-12.5 Trimodal, Poorly Sorted Mud Fine Silt 8.456 3.651 0.024 0.967 RUP03TRIS 12.5-13.0 Trimodal, Poorly Sorted Mud Fine Silt 8.719 3.693 0.038 0.969 RUP03TRIS 13.0-13.5 Trimodal, Poorly Sorted Mud Medium Silt 9.457 3.888 0.039 0.940 RUP03TRIS 13.5-14.0 Polymodal, Poorly Sorted Mud Fine Silt 8.658 3.915 0.022 0.953 RUP03TRIS 14.0-14.5 Bimodal, Poorly Sorted Mud Medium Silt 9.770 3.954 0.039 0.928 RUP03TRIS 15.0-15.5 Trimodal, Poorly Sorted Mud Medium Silt 10.67 3.397 -0.020 0.949 RUP03TRIS 5.5-6.0 Bimodal, Poorly Sorted Mud Fine Silt 7.814 3.243 0.042 0.929

87

RUP03TRIS 6.0-6.5 Trimodal, Poorly Sorted Mud Fine Silt 7.926 3.247 0.006 0.970 RUP03TRIS 6.5-7.0 Bimodal, Poorly Sorted Mud Fine Silt 7.580 3.078 0.007 0.979 RUP03TRIS 7.0-7.5 Trimodal, Poorly Sorted Mud Fine Silt 7.603 3.336 0.004 0.979 RUP03TRIS 7.5-8.0 Bimodal, Poorly Sorted Mud Fine Silt 7.039 3.320 -0.009 0.972 RUP03TRIS 8.0-8.5 Bimodal, Poorly Sorted Mud Fine Silt 7.471 3.434 0.011 0.956 RUP03TRIS 8.5-9.0 Bimodal, Poorly Sorted Mud Medium Silt 7.978 3.439 -0.002 0.969 RUP03TRIS 9.0-9.5 Trimodal, Poorly Sorted Mud Fine Silt 7.100 3.478 0.017 0.974 RUP03TRIS 9.5-10.0 Bimodal, Poorly Sorted Mud Fine Silt 7.326 3.480 0.021 0.969 RUP03TRIS 17.0-18.0 BS Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Fine Silt 11.45 4.366 0.126 0.950 RUP03TRIS 18.0-19.0 BS Polymodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 27.64 5.286 -0.222 0.819 RUP04 6.3-7.3 Bimodal, Poorly Sorted Mud Coarse Silt 15.59 3.026 -0.216 0.977 RUP04 7.3-8.3 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Coarse Silt 19.36 2.985 -0.211 1.074 RUP04 8.3-9.3 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 19.55 2.966 -0.260 1.019 RUP04 9.3-10.3 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Coarse Silt 18.56 3.012 -0.227 1.001 RUP04 10.3-11.3 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Coarse Silt 18.84 3.072 -0.235 1.004 RUP04 11.3-12.3 Bimodal, Poorly Sorted Sandy Mud Very Fine Sandy Coarse Silt 17.81 3.071 -0.211 1.006 RUP04 12.3-13.3 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 20.93 3.009 -0.242 1.015 RUP04 13.3-14.3 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 24.41 3.028 -0.278 1.023 RUP04 14.3-15.3 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 25.32 3.042 -0.230 1.036 RUP04 15.3-16.3 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 25.65 3.405 -0.151 1.020 RUP04 16.3-17.3 Bimodal, Poorly Sorted Sandy Mud Very Fine Sandy Coarse Silt 21.07 3.079 -0.190 1.022 RUP04 17.3-18.3 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 22.69 3.155 -0.188 1.015 RUP04 18.3-19.3 Unimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 30.41 3.129 -0.279 1.004 RUP04 21.0-22.0 BS Trimodal, Poorly Sorted Mud Medium Silt 10.39 3.174 -0.135 0.954 RUP04 22.0-23.0 BS Trimodal, Poorly Sorted Mud Coarse Silt 11.33 3.293 -0.125 0.942 VI18 0.0-0.5 Polymodal, Very Poorly Sorted Sandy Mud Fine Sandy Very Fine Silt 7.196 4.792 0.255 1.069 VI18 0.5-1.0 Trimodal, Poorly Sorted Mud Medium Silt 11.03 3.157 -0.070 0.903 VI18 1.0-1.5 Polymodal, Poorly Sorted Mud Coarse Silt 14.48 2.985 -0.167 0.951 VI18 1.5-2.0 Trimodal, Poorly Sorted Mud Coarse Silt 15.92 2.956 -0.183 0.987 VI18 2.0-2.5 Trimodal, Poorly Sorted Mud Coarse Silt 15.23 2.982 -0.167 0.973

88

VI18 2.5-3.0 Trimodal, Poorly Sorted Mud Medium Silt 11.68 3.343 -0.070 0.927 VI18 3.0-3.5 Trimodal, Poorly Sorted Mud Medium Silt 9.392 3.288 -0.032 0.941 VI18 3.5-4.0 Bimodal, Poorly Sorted Mud Medium Silt 9.441 3.249 -0.035 0.957 VI18 4.0-4.5 Trimodal, Poorly Sorted Mud Medium Silt 9.893 3.464 -0.028 0.929 VI18 4.5-5.0 Polymodal, Poorly Sorted Mud Medium Silt 12.28 3.583 -0.068 0.889 VI18 5.0-5.5 Bimodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 33.02 3.120 -0.403 1.117 VI18 7.0-8.0 BS Trimodal, Poorly Sorted Mud Fine Silt 8.196 3.992 0.137 1.124 VI18 8.0-9.0 BS Bimodal, Poorly Sorted Mud Fine Silt 6.437 3.100 0.023 0.966 VI4 0.0-0.5 Polymodal, Very Poorly Sorted Mud Very Fine Silt 6.585 4.388 0.152 1.016 VI4 0.5-1.0 Trimodal, Poorly Sorted Mud Very Fine Silt 5.026 3.415 0.080 0.987 VI4 1.0-1.5 Polymodal, Poorly Sorted Mud Very Fine Silt 5.583 3.796 0.070 0.947 VI4 3.0-4.0 BS Trimodal, Poorly Sorted Mud Very Fine Silt 5.511 3.614 0.088 0.995 VI4 4.0-5.0 BS Trimodal, Poorly Sorted Mud Very Fine Silt 5.315 3.609 0.094 1.015 VI4 9.0-9.5 Polymodal, Poorly Sorted Mud Very Fine Silt 6.223 3.734 0.049 0.880 VI4 9.5-10.0 Polymodal, Poorly Sorted Mud Medium Silt 7.588 3.740 -0.072 0.885 VI4 10.0-10.5 Polymodal, Very Poorly Sorted Mud Coarse Silt 10.01 4.004 -0.152 0.842 VI4 10.5-11.0 Trimodal, Very Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 13.65 4.069 -0.238 0.826 VI4 20.0-21.0 BS Polymodal, Poorly Sorted Mud Very Fine Silt 5.382 3.885 0.117 1.021 VI8 0.0-0.5 Bimodal, Poorly Sorted Mud Very Fine Silt 4.279 3.245 0.131 1.138 VI8 0.5-1.0 Bimodal, Poorly Sorted Mud Fine Silt 5.187 3.389 0.091 1.039 VI8 1.0-1.5 Trimodal, Poorly Sorted Mud Very Fine Silt 4.347 3.296 0.066 1.054 VI8 3.0-4.0 BS Bimodal, Poorly Sorted Mud Fine Silt 4.610 3.188 0.066 1.105 VI8 4.0-5.0 BS Polymodal, Very Poorly Sorted Mud Fine Silt 5.851 4.363 0.212 1.301 VI8 11.5-12.0 Polymodal, Poorly Sorted Mud Fine Silt 5.501 3.299 -0.031 0.993 VI8 12.0-12.5 Polymodal, Very Poorly Sorted Sandy Mud Fine Sandy Fine Silt 7.065 4.652 0.166 1.183 VI8 12.5-13.0 Trimodal, Poorly Sorted Mud Fine Silt 5.645 3.409 -0.012 1.001 VI8 13.0-13.5 Trimodal, Poorly Sorted Mud Fine Silt 5.822 3.541 0.012 1.012 VI8 13.5-14.0 Polymodal, Poorly Sorted Mud Fine Silt 5.697 3.415 0.002 0.991 VI8 14.0-14.5 Polymodal, Poorly Sorted Mud Fine Silt 5.856 3.635 0.024 1.007 VI8 14.5-15.0 Trimodal, Very Poorly Sorted Mud Fine Silt 7.656 4.152 0.074 0.970

89

VI8 15.0-15.5 Polymodal, Poorly Sorted Sandy Mud Very Fine Sandy Very Coarse Silt 23.03 3.997 -0.408 0.834 VI8 15.5-16.0 Polymodal, Very Poorly Sorted Sandy Mud Fine Sandy Fine Silt 11.45 5.637 0.225 0.924 VI8 19.0-20.0 BS Bimodal, Poorly Sorted Mud Fine Silt 5.056 3.229 0.038 1.042 VI8 20.0-21.0 BS Bimodal, Poorly Sorted Mud Fine Silt 5.004 3.115 0.057 1.030

90