DOCSLIB.ORG

Tracing Exhumation and Orogenic Wedge Dynamics in the European Alps with Detrital Thermochronology

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Tracing Exhumation and Orogenic Wedge Dynamics in the European Alps with Detrital Thermochronology Tracing exhumation and orogenic wedge dynamics in the European Alps with detrital thermochronology Barbara Carrapa Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA ABSTRACT lag time upsection (e.g., Bernet et al., 2001; Detrital cooling ages from the pro-foreland and retro-foreland basins of the European Carrapa et al., 2003a) (Fig. 2). In turn, the rate Alps record distinctive exhumation trends that correlate with orogenic wedge states inferred of migration of the fl exural wave into the fore- from thrust front propagation rates. Periods of rapid hinterland exhumation correlate with land is expected to be slower during subcritical relatively slow propagation of deformation toward the foreland and are interpreted to rep- conditions and faster during supercritical condi- resent subcritical wedge conditions, whereas periods of slow hinterland exhumation corre- tions. If those processes have infl uenced Alpine late with rapid propagation of deformation toward the foreland and indicate supercritical exhumation along and across strike, we should wedge conditions. Similar lag time trends recorded in both the pro-foreland and retro-fore- expect to fi nd characteristic trends in the detri- land thus mimic orogenic wedge behavior and suggest that local tectonics and/or climate tal record (von Eynatten et al., 1999; Spiegel et events do not overprint the regional signal. al., 2001, 2004; Carrapa et al., 2003a, 2004a, 2004b; von Eynatten and Wijbrans, 2003). INTRODUCTION These processes, combined with later deforma- The internal structure, kinematic history, tional and thermal events, produced the distri- ALPINE FORELAND BASIN RECORD and surface topography of contractional moun- bution of thermochronological ages observed The area considered in this study covers the tain belts are products of complex interactions today (Fig. 1). entire orogenic system (Fig. 1) and the prove- between crustal shortening and/or thickening The Alps are formed by two oppositely verg- nance of most of the samples is well constrained and exhumation. Numerous studies have shown ing tapered orogenic wedges (Figs. 1B and 2), by sandstone and conglomerate petrography and that mountain belts can be successfully mod- and loading of the upper plate by these wedges paleocurrent data (e.g., Brügel, 1998; Carrapa eled as critically tapered orogenic wedges (e.g., produced foreland basins on both sides of the and DiGiulio, 2001; Evans and Elliott, 1999; Davis et al., 1983; Suppe and Medwedeff, 1990; orogen (Naylor and Sinclair, 2008). Critical Spiegel et al., 2002; Dunkl et al., 2001, and Willett et al., 1993; Koons, 1994; DeCelles and taper theory (e.g., Chapple, 1978; Davis et al., Carrapa et al., 2004a, and references therein). Mitra, 1995). Critical taper models make predic- 1983) predicts that the front of an orogenic Medium- to low-temperature detrital thermo- tions about the kinematic history of an orogenic wedge develops taper and propagates toward chronological data from the pro-foreland and wedge in response to changes in mass distribu- the foreland when the sum of the angles of retro-foreland basins of the Western, Central, tion, which in turn is controlled by exhumation. the basal and upper slopes (referred to as the and Eastern Alps (Fig. 3) show that different Therefore, in order to understand the relation- taper value) reaches a critical value. When the thermochronometers record similar patterns of ships between exhumation and kinematic pro- taper value is less than the critical value (sub- exhumation. This suggests that differences in lag cesses it is essential to determine the timing, critical), the wedge will shorten internally by time responses for different thermo chrono meters rates, and spatial distribution of exhumation. out-of-sequence thrusting and/or duplexing to are undetectable at this scale of observation and The European Alps are a classic example of build thickness and increase taper. Among other that sediment reworking is not a problem. a strongly asymmetrical continent-continent col- things, subcritical conditions could be caused In the pro-foreland of the Central and Eastern lisional orogen and one of the few cases of a dou- by enhanced erosion due to wetter or more sea- Alps, the decreasing lag-time trend (Fig. 3A) bly verging orogen with two foreland basin sys- sonal climate. If the taper value is greater than suggests increasing exhumation from ca. 30 to 10 tems (e.g., Naylor and Sinclair, 2008). The North the critical value (supercritical), the orogenic Ma, suggesting subcritical taper conditions. The and South Alpine foreland basins provide a natu- wedge will broaden and reduce the overall pro-foreland of the Western Alps records increas- ral laboratory in which to explore the distribu- taper angle by forward thrust propagation and/ ing exhumation between 38 and 36 Ma (suggest- tion of exhumation along (east-west) and across or internal extension in order to regain balance ing a subcritical state) and decreasing exhuma- (north-south) the orogen over tens of millions of between driving and resisting forces. Exhuma- tion between ca. 16 and 8 Ma (supercritical state) years. This paper documents the relationships tion of material from the wedge may be viewed (Fig. 3B). Deep and rapid exhumation is also between orogenic wedge taper and exhumation as a response to changing taper states (Davis et indicated by ca. 34 Ma 40Ar/39Ar ages from peb- in the Alps with detrital thermochronology. al., 1983; DeCelles and Mitra, 1995). Therefore, bles in early Oligocene synorogenic conglomer- if the Alps obey wedge theory, increasing hin- ates in the French Alps (Morag et al., 2008). WEDGE TECTONICS, terland exhumation refl ects a subcritical wedge In the retro-foreland of the Western Alps EXHUMATION, AND DETRITAL state, whereas decreasing hinterland exhuma- (Fig. 3C) the youngest thermochronological THERMOCHRONOLOGY tion refl ects a supercritical wedge state. Increas- signal (ca. 32–38 Ma) remains constant for >30 The Alpine chain formed as a consequence of ing exhumation will be recorded by detrital m.y. This represents rapid cooling and episodic convergence and subsequent collision between minerals within foreland basin strata with an exhumation of the internal crystalline massifs the Eurasian and African continents from early upsection-decreasing lag time (e.g., Garver et (e.g., Dora Maira) between ca. 38 and 32 Ma to middle Cenozoic time (e.g., Stampfl i and al., 1999) between cooling and depositional (e.g., Carrapa et al., 2003a) and of the Periadri- Marchant, 1997; Rosenbaum and Lister, 2005). ages, whereas decreasing exhumation will be atic plutons (e.g., Bergell) in the Central Alps This was responsible for signifi cant shortening recorded by an increasing lag time upsection. (e.g., Garzanti and Malusá, 2008), suggesting (as much as 195 km; Ford et al., 2006; Schmid Episodic exhumation will be recorded by an subcritical wedge conditions. This was fol- and Kissling, 2000; Pfi ffner et al., 2000), crustal increasing lag time upsection, whereas steady- lowed by slower cooling (~10°/m.y.), indicating thickening of the upper plate, and exhumation. state exhumation will be recorded by a constant a supercritical wedge state. It is interesting that © 2009 Geological Society of America. For permission to copy, contact Copyright Permissions, GSA, or [email protected]. GEOLOGY,Geology, December December 2009; 2009 v. 37; no. 12; p. 1127–1130; doi: 10.1130/G30065A.1; 4 fi gures. 1127 48°N ages from the Friuli-Venetian foreland (Eastern A (11) Alps derived) indicate a change in lag time trend Pro-foreland ca. 12 Ma that may correspond to a change in tectono-thermal regime, possibly related to (9) exhumation of the Lepontine Dome (Spiegel et A (10)(10)* 47°N al., 2004; von Eynatten and Wijbrans, 2003). Swiss Molasse basin Aar G THRUST FRONT PROPAGATION, K-Ar and40 Ar/ 39 Ar ages: 140–60 Ma LD SUBSIDENCE, AND EXHUMATION 30–60 Ma From ca. 40 to 30 Ma the North Alpine pro- 30–15 Ma 46°N 15–0 Ma foreland basin (Swiss Molasse Basin) was an MB DB ZFT ages < 20 Ma (1)(2)(5) ~100-km-wide, deeply underfi lled fl exural AFT ages < 15 Ma G SL trough with <200 m of sedimentary fi ll. The AFT ages < 5 Ma B GP pro-wedge thrust front advanced northward at Milano (6) Retro-foreland high rates of 10–20 mm/a (Sinclair and Allen, Torino 45°N Po Plain 1992; Burkhard and Sommaruga, 1998). This TPB correlates to a supercritical wedge behavior. (7) (8) Between 30 and 22 Ma, both the thrust front Pro-foreland DM Alpes de and the distal foreland basin depositional pin- Arg Apennine(3)(4) foreland (12)(12*) Proven e (4)* chout migrated northwestward at a slower rate Digne Haute 44°N Valensole ç of ~5 mm/a (Fig. 4). Increased tectonic subsi- basin Bâ rreme dence (2.7 km) produced a basin that was totally basin Nice Ligurian Sea fi lled above sea level by sediment (Sinclair and Allen, 1992; Burkhard and Sommaruga, 1998). The thermochronological lag time decreased 43°N during this time (30–12 Ma), indicating increas- 4E° 5°E 6°E 7°E 8°E 9°E 10°E 11°E 12°E ing exhumation (Fig. 3A) and subcritical taper B Pro-foreland Retro-foreland conditions. An increase in sediment fl ux into the A AU MA MO HE PF NCA PA AU PA IL SA B foreland basin, between 30 and 22 Ma (Kuhle- mann et al., 2002), correlates with an increase VA SU B TA in source exhumation. From 22 to 12 Ma, the Aar 10 AD foreland basin depositional pinchout continued GO A A 20 1 34 5 to migrate northwestward at a slower rate. The B 2 B km basin had a width of ~100–140 km, and rapid Figure 1. Digital elevation model of Alps and fl anking foreland basins with compilations of subsidence continued (Burkhard and Somma- 40Ar/ 39Ar ages younger than 140 Ma (after Hunziker et al., 1992, and references therein), zircon ruga, 1998).
Load more

Recommended publications
  • Rollback Orogeny Model for the Evolution of the Swiss Alps
    Research Collection Journal Article Rollback Orogeny Model for the Evolution of the Swiss Alps Author(s): Kissling, Edi; Schlunegger, Fritz Publication Date: 2018-04 Permanent Link: https://doi.org/10.3929/ethz-b-000268411 Originally published in: Tectonics 37(4), http://doi.org/10.1002/2017TC004762 Rights / License: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International This page was generated automatically upon download from the ETH Zurich Research Collection. For more information please consult the Terms of use. ETH Library Tectonics RESEARCH ARTICLE Rollback Orogeny Model for the Evolution 10.1002/2017TC004762 of the Swiss Alps Key Points: Edi Kissling1 and Fritz Schlunegger2 • Central Alpine orogeny driven by mantle llithosphere rollback 1Institute of Geophysics, ETH Zürich, Zürich, Switzerland, 2Institute of Geological Sciences, University of Bern, Bern, subduction • No hard collision between two Switzerland continents required to build up the Alps • Deep crustal root compensating loads Abstract The construction of the European Alps and the Himalayas has been related to the convergence of relatively low topography and and subsequent collision of two continental plates. Nearly all models of orogeny build on this concept, and all mantle slab of them relate the stacking of nappes and the buildup of topography to compressional forces at work in response to the collision between two continental plates. For the central European Alps, however, these models fail to explain the first-order observations of a mountain belt, which particularly includes the striking Correspondence to: isostatic imbalance between the low surface topography and the thick crust beneath the Alps. Here we E. Kissling, review and synthesize data on the geologic architecture of the central Alps, the chronology and pattern of [email protected] crustal deformation, and information about the deep crustal structure derived from seismic tomography.
    [Show full text]
  • International Society for Soil Mechanics and Geotechnical Engineering
    INTERNATIONAL SOCIETY FOR SOIL MECHANICS AND GEOTECHNICAL ENGINEERING This paper was downloaded from the Online Library of the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE). The library is available here: https://www.issmge.org/publications/online-library This is an open-access database that archives thousands of papers published under the Auspices of the ISSMGE and maintained by the Innovation and Development Committee of ISSMGE. UNDER THE HIGH PATRONAGE OF SOUS LE HAUT PATRONAGE DU Swiss F ederal C ouncil Conseil F édéral de la C onfédération Suisse Cantonal G overnment of Z ur ich C onseil d ’Etat du Canton de Z ur ich Cantonal G overnment of Va ud Conseil d ’Etat du Canton de Va ud T own Council of Z ur ich C onseil M unicipa l de la Vil l e de Z ur ich T own Council of L ausanne C onseil M unicipa l de la Vil l e de L ausanne Board of t he Swiss F ederal Institute of T echnology Conseil de l’E cole polytechnique fédérale GUESTS OF HONOUR Dr. P h . Etter President of the Swiss Confederation Dr. P. M eierhans Councillor to the Cantonal Government of Zurich P. O guey Councillor to the Cantonal Government of Vaud J. Baumann Municipal Councillor of Zurich J. P eit r equin Municipal Councillor of Lausanne Prof. Dr. H. Pallmann President of the Board of the Swiss Federal Institute of Technology, Zurich Prof. Dr. h. c. A. R ohn Formerly President of the Board of the Swiss Federal Institute of Technology, Zurich Prof.
    [Show full text]
  • Connecting Quartz Fluid Inclusion, Fissure Monazite Age, and Fissure
    Gnos et al. Swiss J Geosci (2021) 114:14 https://doi.org/10.1186/s00015-021-00391-9 Swiss Journal of Geosciences ORIGINAL PAPER Open Access Episodes of fssure formation in the Alps: connecting quartz fuid inclusion, fssure monazite age, and fssure orientation data Edwin Gnos1* , Josef Mullis2, Emmanuelle Ricchi3, Christian A. Bergemann4, Emilie Janots5 and Alfons Berger6 Abstract Fluid assisted Alpine fssure-vein and cleft formation starts at prograde, peak or retrograde metamorphic conditions of 450–550 °C and 0.3–0.6 GPa and below, commonly at conditions of ductile to brittle rock deformation. Early-formed fssures become overprinted by subsequent deformation, locally leading to a reorientation. Deformation that follows fssure formation initiates a cycle of dissolution, dissolution/reprecipitation or new growth of fssure minerals enclos- ing fuid inclusions. Although fssures in upper greenschist and amphibolite facies rocks predominantly form under retrograde metamorphic conditions, this work confrms that the carbon dioxide fuid zone correlates with regions of highest grade Alpine metamorphism, suggesting carbon dioxide production by prograde devolatilization reac- tions and rock-bufering of the fssure-flling fuid. For this reason, fuid composition zones systematically change in metamorphosed and exhumed nappe stacks from diagenetic to amphibolite facies metamorphic rocks from saline fuids dominated by higher hydrocarbons, methane, water and carbon dioxide. Open fssures are in most cases oriented roughly perpendicular to the foliation and lineation of the host rock. The type of fuid constrains the habit of the very frequently crystallizing quartz crystals. Open fssures also form in association with more localized strike-slip faults and are oriented perpendicular to the faults.
    [Show full text]
  • Structure, Geometry and Kinematics of the Northern Adula Nappe (Central Alps)
    Swiss J Geosci (2014) 107:135–156 DOI 10.1007/s00015-014-0175-7 Structure, geometry and kinematics of the northern Adula nappe (Central Alps) Mattia Cavargna-Sani • Jean-Luc Epard • Albrecht Steck Received: 13 May 2013 / Accepted: 28 October 2014 / Published online: 21 November 2014 Ó Swiss Geological Society 2014 Abstract The eclogitic Adula nappe of the Central Alps zone involving the entire nappe and responsible for the (cantons Graubu¨nden and Ticino, Switzerland) displays an emplacement of the Lower Penninic sediments and the exceptionally complex internal structure with the particu- Middle Penninic nappes in the eastern part of the Lepontine larity of enclosing numerous slices of Mesozoic cover Dome. rocks (Internal Mesozoic) within the Palaeozoic gneiss basement. This study is principally based on detailed lith- Keywords Alpine orogeny Á Fold structures Á ological and structural mapping of selected areas of the Nappe emplacement Á High-pressure metamorphism Á northern Adula nappe. Specific focus was placed on the Switzerland Á Pennine zone Mesozoic slivers embedded in pre-Mesozoic basement (Internal Mesozoic). The most pervasive structures are related to the Zapport deformation phase that is responsible 1 Introduction for the development of a fold-nappe and ubiquitous north- directed shear. Locally, the structures in the upper and Eclogitic rocks in mountain belts are commonly associated frontal part of the nappe can be assigned to the older with a suture zone tracing old subduction zones (Ernst ductile Ursprung phase. These earlier structures are only 1971; Dal Piaz et al. 1972; Ernst 1973). Nappes containing compatible with top-to-S shear movement.
    [Show full text]
  • Basement Lithostratigraphy of the Adula Nappe: Implications for Palaeozoic Evolution and Alpine Kinematics
    Int J Earth Sci (Geol Rundsch) (2014) 103:61–82 DOI 10.1007/s00531-013-0941-1 ORIGINAL PAPER Basement lithostratigraphy of the Adula nappe: implications for Palaeozoic evolution and Alpine kinematics Mattia Cavargna-Sani • Jean-Luc Epard • Franc¸ois Bussy • Alex Ulianov Received: 6 March 2013 / Accepted: 8 July 2013 / Published online: 20 August 2013 Ó Springer-Verlag Berlin Heidelberg 2013 Abstract The Adula nappe belongs to the Lower Penni- are pre-Alpine in age. Consequently, me´lange models for nic domain of the Central Swiss Alps. It consists mostly of the Tertiary emplacement of the Adula nappe are not pre-Triassic basement lithologies occurring as strongly consistent and must be rejected. The present-day structural folded and sheared gneisses of various types with mafic complexity of the Adula nappe is the result of the intense boudins. We propose a new lithostratigraphy for the Alpine ductile deformation of a pre-structured entity. northern Adula nappe basement that is supported by detailed field investigations, U–Pb zircon geochronology, Keywords Adula nappe Á Central Alps Á Palaeozoic and whole-rock geochemistry. The following units have basement Á U–Pb dating Á Zircon been identified: Cambrian clastic metasediments with abundant carbonate lenses and minor bimodal magmatism (Salahorn Formation); Ordovician metapelites associated Introduction with amphibolite boudins with abundant eclogite relicts representing oceanic metabasalts (Trescolmen Formation); Palaeozoic basement rocks in the Alpine realm experienced Ordovician peraluminous
    [Show full text]
  • Abstract Title
    16th Swiss Geoscience Meeting, Bern 2018 Relationships of banded amphibolites and Ordovician orthogneisses in pre-Variscan basements of the Alps Roger Zurbriggen Feldmatt 10, CH-6206 Neuenkirch ([email protected]) Despite of the individual character of each of the pre-Variscan basement units of the Alps, they show analogous formations (paragneisses, migmatites, peraluminous orthogneisses, and amphibolites) and structures indicating similar genetic processes. There is consensus regarding the protoliths of the gneisses and migmatites. But the protoliths of the amphibolites are under discussion because their age is largely unknown and original structures often are overprinted by Variscan and Alpine tectonics. However, the amphibolites (i) are typically banded from millimeter to meter-scale (in all units; e.g., Fig. 1a), (ii) are intercalated with para- and orthogneisses on a map-scale (especially in the Aar massif and Silvretta nappe), (iii) can vary in percentage from 3 area% (Strona- Ceneri zone) to 22 area% (Silvretta nappe), (iv) are associated with metagabbros, meta-ultramafics and (meta-) eclogites (in all units), (v) can be migmatic and occur within migmatite formations (Aar massif). Most studies interpret the banded amphibolites as members of an ophiolite sequence (due to their MORB signature and association with eclogites and ultramafic rocks) or bimodal metavolcanics (due to their compositional banding). Both tectonic settings are supported by case studies. But from a general perspective of subduction-accretion tectonics of the Ordovician orogeny (Fig. 1b and Zurbriggen 2017) they cannot serve as main setting due to following reasons: A clear ubiquitous ophiolite stratigraphy is lacking and obduction is the exception rather than the rule in accretionary complexes.
    [Show full text]
  • Rollback Orogeny Model for the Evolution of the Swiss Alps
    Tectonics RESEARCH ARTICLE Rollback Orogeny Model for the Evolution 10.1002/2017TC004762 of the Swiss Alps Key Points: Edi Kissling1 and Fritz Schlunegger2 • Central Alpine orogeny driven by mantle llithosphere rollback 1Institute of Geophysics, ETH Zürich, Zürich, Switzerland, 2Institute of Geological Sciences, University of Bern, Bern, subduction • No hard collision between two Switzerland continents required to build up the Alps • Deep crustal root compensating loads Abstract The construction of the European Alps and the Himalayas has been related to the convergence of relatively low topography and and subsequent collision of two continental plates. Nearly all models of orogeny build on this concept, and all mantle slab of them relate the stacking of nappes and the buildup of topography to compressional forces at work in response to the collision between two continental plates. For the central European Alps, however, these models fail to explain the first-order observations of a mountain belt, which particularly includes the striking Correspondence to: isostatic imbalance between the low surface topography and the thick crust beneath the Alps. Here we E. Kissling, review and synthesize data on the geologic architecture of the central Alps, the chronology and pattern of [email protected] crustal deformation, and information about the deep crustal structure derived from seismic tomography. Furthermore, we discuss the intrinsic and explicit assumptions in the kinematic models of Alpine evolution in Citation: the context of plate tectonic considerations. We combine these views with progress in understanding that Kissling, E., & Schlunegger, F. (2018). Rollback orogeny model for the has been gained through subduction and collision, isostatic mass and force balancing and with information evolution of the Swiss Alps.
    [Show full text]
  • Miocene Basement Exhumation in the Central Alps Recorded by Detrital
    https://doi.org/10.5194/se-2019-98 Preprint. Discussion started: 14 June 2019 c Author(s) 2019. CC BY 4.0 License. 1 Miocene basement exhumation in the Central Alps recorded 2 by detrital garnet geochemistry in foreland basin deposits 3 Laura Stutenbecker1*, Peter M.E. Tollan2, Andrea Madella3, Pierre Lanari2 4 5 1Institute of Applied Geosciences, Technische Universität Darmstadt, Schnittspahnstr. 9, 6 64287 Darmstadt, Germany 7 2Institute of Geological Sciences, University of Bern, Baltzerstrasse 1+3, 3012 Bern, 8 Switzerland 9 3Department of Geosciences, University of Tuebingen, Wilhelmstr. 56, 72074 Tübingen, 10 Germany 11 *corresponding author: [email protected] 12 Abstract 13 The Neogene evolution of the European Alps was characterized by the exhumation of crystalline 14 basement, the so-called external crystalline massifs. Their exhumation presumably controlled the 15 evolution of relief, distribution of drainage networks and generation of sediment in the Central Alps. 16 However, due to the absence of suitable proxies, the timing of their surficial exposure, and thus the 17 initiation of sediment supply from these areas, are poorly constrained. 18 The northern alpine foreland basin preserves the Oligocene to Miocene sedimentary record of tectonic 19 and climatic adjustments in the hinterland. This contribution analyses the provenance of 25 to 14 My- 20 old alluvial fan deposits by means of detrital garnet chemistry. Unusually grossular- and spessartine- 21 rich garnets are found to be unique proxies for identifying detritus from the external crystalline 22 massifs. In the foreland basin, these garnets are abundant in 14 My-old deposits, thus providing a 23 minimum age for the surficial exposure of the crystalline basement.
    [Show full text]
  • Large-Scale Crustal-Block-Extrusion During Late Alpine Collision
    Research Collection Journal Article Large-Scale Crustal-Block-Extrusion During Late Alpine Collision Author(s): Herwegh, Marco; Berger, Alfons; Baumberger, Roland; Wehrens, Philip; Kissling, Edi Publication Date: 2017-03-24 Permanent Link: https://doi.org/10.3929/ethz-b-000130321 Originally published in: Scientific Reports 7, http://doi.org/10.1038/s41598-017-00440-0 Rights / License: Creative Commons Attribution 4.0 International This page was generated automatically upon download from the ETH Zurich Research Collection. For more information please consult the Terms of use. ETH Library www.nature.com/scientificreports OPEN Large-Scale Crustal-Block- Extrusion During Late Alpine Collision Received: 12 September 2016 Marco Herwegh 1, Alfons Berger1, Roland Baumberger1,2, Philip Wehrens1,2 & Edi Kissling3 Accepted: 27 February 2017 The crustal-scale geometry of the European Alps has been explained by a classical subduction- Published: xx xx xxxx scenario comprising thrust-and-fold-related compressional wedge tectonics and isostatic rebound. However, massive blocks of crystalline basement (External Crystalline Massifs) vertically disrupt the upper-crustal wedge. In the case of the Aar massif, top basement vertically rises for >12 km and peak metamorphic temperatures increase along an orogen-perpendicular direction from 250 °C–450 °C over horizontal distances of only <15 km (Innertkirchen-Grimselpass), suggesting exhumation of midcrustal rocks with increasing uplift component along steep vertical shear zones. Here we demonstrate that delamination of European lower crust during lithosphere mantle rollback migrates northward in time. Simultaneously, the Aar massif as giant upper crustal block extrudes by buoyancy forces, while substantial volumes of lower crust accumulate underneath. Buoyancy-driven deformation generates dense networks of steep reverse faults as major structures interconnected by secondary branches with normal fault component, dissecting the entire crust up to the surface.
    [Show full text]
  • Volcanism and Volcanogenic Submarine Sedimentation in the Paleogene Foreland Basins of the Alps: Reassessing the Source-To-Sink Systems with an Actualist View
    geosciences Review Volcanism and Volcanogenic Submarine Sedimentation in the Paleogene Foreland Basins of the Alps: Reassessing the Source-to-Sink Systems with an Actualist View Andrea Di Capua 1,* , Federica Barilaro 2 and Gianluca Groppelli 1 1 Institute of Environmental Geology and Geoengineering, Italian National Research Council (CNR), Via Mario Bianco 9, 20131 Milano, Italy; [email protected] 2 Department of Theoretical and Applied Sciences, Previously at University of Insubria, 21100 Varese, Italy; [email protected] * Correspondence: [email protected] Abstract: This work critically reviews the Eocene–Oligocene source-to-sink systems accumulating volcanogenic sequences in the basins around the Alps. Through the years, these volcanogenic sequences have been correlated to the plutonic bodies along the Periadriatic Fault System, the main tectonic lineament running from West to East within the axis of the belt. Starting from the large amounts of data present in literature, for the first time we present an integrated 4D model on the evolution of the sediment pathways that once connected the magmatic sources to the basins. The magmatic systems started to develop during the Eocene in the Alps, supplying detritus to the Adriatic Foredeep. The progradation of volcanogenic sequences in the Northern Alpine Foreland Basin is subsequent and probably was favoured by the migration of the magmatic systems to the North and to the West. At around 30 Ma, the Northern Apennine Foredeep also was fed by large volcanogenic inputs, but the palinspastic reconstruction of the Adriatic Foredeep, together with Citation: Di Capua, A.; Barilaro, F.; stratigraphic and petrographic data, allows us to safely exclude the Alps as volcanogenic sources.
    [Show full text]
  • Abstract Volume 17Th Swiss Geoscience Meeting Fribourg, 22Nd + 23Rd November 2019
    Abstract Volume 17th Swiss Geoscience Meeting Fribourg, 22nd + 23rd November 2019 Geoscience goes underground: understanding resources & processes II Geoscience goes underground Knowledge of the shallow and deep underground has ever-growing importance in modern society. This is espe- cially true for Switzerland, which has a longstanding tradition of exploring the deep that was acquired over the course of decades of building tunnels throughout its territories. Hydrocarbon exploration of the Alpine Molasse Basin and the Jura fold-and-thrust belt yielded modest successes, but the public controversy regarding shale gas exploration and induced seismicity in the wake of deep geothermal exploration has highlighted the importance and the role of communication of our geoscientific knowledge to the public. The extraction of geothermal energy, building management, and land use planning will increasingly rely on knowledge of the near and deep subsurface geology. Natural resources of the underground, such as geothermal energy (from shallow to deep), CO2 sequestration, shale gas, reservoir technology, water exploitation, subsurface energy storage, or “classic” mineral resources will thereby play a central role in the future. Geodata, GeoBIM, GeoCIM projects, and 3D geology models will reshape future management and use of underground resources and geoscientists must not miss the opportunity to get involved. Indeed, geoscientists should reach out to poli- ticians and the public and take a position in a debate that will become increasingly more complex.
    [Show full text]
  • The Adula Nappe: Stratigraphy, Structure and Kinematics of an Exhumed High-Pressure Nappe
    Unicentre CH-1015 Lausanne http://serval.unil.ch Year : 2013 THE ADULA NAPPE: STRATIGRAPHY, STRUCTURE AND KINEMATICS OF AN EXHUMED HIGH-PRESSURE NAPPE Cavargna-Sani Mattia Cavargna-Sani Mattia, 2013, THE ADULA NAPPE: STRATIGRAPHY, STRUCTURE AND KINEMATICS OF AN EXHUMED HIGH-PRESSURE NAPPE Originally published at : Thesis, University of Lausanne Posted at the University of Lausanne Open Archive. http://serval.unil.ch Droits d’auteur L'Université de Lausanne attire expressément l'attention des utilisateurs sur le fait que tous les documents publiés dans l'Archive SERVAL sont protégés par le droit d'auteur, conformément à la loi fédérale sur le droit d'auteur et les droits voisins (LDA). A ce titre, il est indispensable d'obtenir le consentement préalable de l'auteur et/ou de l’éditeur avant toute utilisation d'une oeuvre ou d'une partie d'une oeuvre ne relevant pas d'une utilisation à des fins personnelles au sens de la LDA (art. 19, al. 1 lettre a). A défaut, tout contrevenant s'expose aux sanctions prévues par cette loi. Nous déclinons toute responsabilité en la matière. Copyright The University of Lausanne expressly draws the attention of users to the fact that all documents published in the SERVAL Archive are protected by copyright in accordance with federal law on copyright and similar rights (LDA). Accordingly it is indispensable to obtain prior consent from the author and/or publisher before any use of a work or part of a work for purposes other than personal use within the meaning of LDA (art. 19, para. 1 letter a).
    [Show full text]