The Oligocene Central Swiss Molasse Basin As an Example Fritzschlunegg Erl and Teresa E

Total Page:16

File Type:pdf, Size:1020Kb

The Oligocene Central Swiss Molasse Basin As an Example Fritzschlunegg Erl and Teresa E View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Bern Open Repository and Information System (BORIS) TECTONICS, VOL. 16, NO. 5, PAGES 823-840, OCTOBER 1997 Controls of erosional denudation in the orogen on foreland basin evolution: The Oligocene central Swiss Molasse Basin as an example FritzSchlunegg erl and Teresa E. Jordan DepartmentofEarth Sciences, Cornell University, Ithaca, New York EvaMafia Klaper GeologischesInstitut, Universitat Bern, Bern, Switzerland Abstract. A high-resolution three-dimensionalreconstruc- 1. Introduction tionof the 25-m.y.-old central Swiss Molasse Basin reveals Forelandbasins have been extensivelystudied becausethey twosedimentary domains separated by a ~5-km-wide flood- chroniclein greatdetail the tectonicand denudationhistory of plain.The proximal domain of thebasin attained a width of 20 the boundingmountain belt [Jordan,1981]. Whereasit is now kin, and its basement is steeply flexed (6ø-7ø dip). widely understoodthat crustaland/or subcrustalloading con- Petrographicdata indicate that it wasfilled by sedimentfrom trols basin subsidence,relationships between erosional de- theRigi dispersalsystem derived from the central Alps of nudationand the geometricaland architecturalevolution of easternSwitzerland and by locally sourcedbajadas. In contrast, forelandbasins have been postulatedbut not yet adequately the distal sedimentary domain, located farther north, was investigated[Flemings and Jordan, 1989, 1990; Jordanand gentlydipping (<2 ø) and was filled by the meanderingLac Flemings, 1991; Paolaetal., 1992]. L6manand Honegg dispersalsystems. Chronological data re- vealthat sedimentationin the northern proximal part of the A successfulreconstruction of the relationships between basinstarted at ~27 Ma, when sediment supply to the basin crustalthickening and erosionaldenudation of the orogenand startedto increase.Deflection of the foreland plate at ~25 Ma the evolution of the adjacent foreland basin requires (1) is successfullysimulated by flexural modeling of the thrust knowledgeof the structuralgeometries and the deformation load and the sediment load. The model reveals that the Lac historyin the hinterland,(2) cooling ages to assessthe long- L•manand Honegg dispersal systems are locatedon a buried termrate and the spacialhistory of denudation,(3) a high-res- olution reconstruction of the architecture of the foreland basin, flexuralbulge. Furthermore,it showsthat burial and suppres- sionof the flexural bulge at ~27 Ma as well as an increaseof (4) petrographicdata from the forelandbasin to locate the thebasin wavelength were controlledby the contemporaneous sourcearea, and (5) knowledgeof the mechanicalproperties of increasein the sedimentsupply rate of the Rigi system.The the forelandplate [DeCellesand Mitra, 1995]. The Oligo- modelpresented suggests that the tectonic subsidenceof the Miocene Alps/Molasse Basin, which is among the best MolasseBasin was mainly controlledby tectonicevents in the understoodorogen-basin systems in the world, meetsmost of northernpart of the orogen,within ~70 km distancefrom the theserequirements [Pfiffner, 1986; $chmidet al., 1996]. On tipof the orogenicwedge. Crustalthickening in this part of the basis of flexural modeling and high-resolution magne- theorogen is reflectedin the proximal Molasse by sedimen- tostratigraphy,Sinclair et al. [1991], Royden [1993], and tarycycles characterized by an increasein the sedimentaccu- $chluneggeret al. [199r/a,b] revealedthe stratigraphicaland mulationrates up section and by the presenceof locally geometricalreponse of the MolasseBasin to crustalloading in sourcedbajada fans at the top of each cycle. Althoughsouth theAlpine orogen. Using a forwarddiffusion model of moun- vergentback thrusting along the InsubricLine ~150 km south tain belt uplift and erosion, Sinclair and Allen [1992] pro- of the foreland basin contributed little to flexure, it resulted in posedthe conceptsof linking erosionaldenudation in the hin- terland to basin architecture. anincrease of thesediment supply to the forelandbasin. This isreflected in the Molasseby coarseningand thickeningup- In thispaper, we reconstructthe three-dimensional architec- ture and the deflection of the 25-m.y.-old Molasse Basin of wardtrends, an increaseof the basin wavelength,basinward centralSwitzerland. The reconstructionis based on a compila- shiftsof the depocentersof the dispersalsystems, and uplift tionof publishedchronological and stratigraphicaldata and on anderosion of the proximalbasin borden newsedimentological and petrographicalstudies carried out for three outcrop sections. Further attention is focused on restoringthe Alpinethrust load and the sedimentload of the INowat Insitut fiir Geowissenschaften, Friedrich-Schiller-Universit•it Molasse Basin at ~25 Ma. This guessof the load distribution Jena,Jena, Germany. in the late ¸ligocene as well as determinationof the foreland platedeflection are used to estimatethe mechanicalproperties Copyright1997 by the American Geophysical Union. of theforeland plate by flexural modeling.The resultof these Papernumber 97TC01657. calculationsallows us to evaluate to what extent the sediment 0278-7407/97/TC_01657512.00 load controlled the basin subsidence. This evaluation will be 823 824 SCHLUNEGGERET AL.:MOLASSE BASIN AND ALPINE DENUDATION usedto discussthe significanceof sedimentsupply as a control [Berli,1985; Keller, 1989; Hurni, 1991; Schlunegger et on the geometricaland stratigraphicalevolution of the central 1993]. It endswith Serravalianfluvial elasticsof theOSM. Swiss Molasse Basin in the early Chattian (30-25 Ma) The Rupelianto early Chattiandeposits of central [Schluneggeret at., 1996]. Switzerlandcompose theLower Marine Molasse group (UMM• andthe lower Lower Freshwater Molasse group (USM I of 2. Geological Setting Schlanke[1974]). The UMM formsthe transitionfrom the earlyunderfilled "Flysch" stage of the northAlpine foreland The present-dayAlps are the resultof the continent-conti- basinto the overfilled "Molasse" stage [Sinclair et al.,1991; nentcollision between the Adriaticpromontory of Africa and Sinclairand Allen, 1992]. It consistsof deepmarine turbidites the Europeanplate that startedin the Late Cretaceous[Lihou at itsbase, overlain by a regressivesequence comprising off. and Allen, 1996]. The Alps form a doubly vetgent compres- shoremudstones, nearshore sandstone/mudstone alternations, sionalorogen that consistsof thin-skinnedand thick-skinned and shorefacesandstones [Diem, 1986]. At the Alpinethrust mostlyunmetamorphosed thrust sheets at their externalflanks front,contemporaneous fan deltas interfingered with the peri. andhigh-grade metamorphic rocks in their core [Laubscher, alpine sea(O. Kempf, personalcommunication, 1995). The 1990: Schi•'nborn,1992; Pfiffner, 1992; $chmideta!., 1996] USMI consistsof bajadasand alluvial megafans at the tip 0[ (Figurela). On the basisof the geologicalinterpretation of theorogenic wedge, which pass down current into conglomer. geophysicaldata, Laubscher[1990], Pfiffner [1992] and ate channelbelt, sandstonechannel belt and floodplainde. Schmidet al. [1996] could show that collisionbetween the two posits [Schluneggeret al., !997b]. platesoccurred by insertionof the Adriaticlower crust into the At the Alpineborder, the Oli goceneMolasse is presentin a interfacebetween the southdipping European lower crustand stackof southwarddipping thrust sheets (Subalpine Molasse), the Europeanupper crust (Figure 1b). which in turn are overlainby the Helveticthrust nappes In the north, the present-dayAlpine edifice consistsof the (Figure 2). The Plateau Molasse, which representsthe more Helvetic zone, which is subdivided into a lower Infrahelvetic distalpart of the basin,is mainlyfiat lying and gentlydips complex(Aar massifand its autochthonous- parautochthonous toward the Alpine orogen. However, synsedimentaryunder. cover)and an upperHelvetic (sensu stricto) complex (Helvetic plating of USM thrust sheets beneath the Plateau Molassere. thrustnappes), separated by the north vetgentbasal Helvetic sultedin backthrusting of the latterunit and in the develop- thrust (Figure lb). In the easternpart of the Swiss Alps, the ment of a classicaltriangle zone just north of the Subalpine Helvetic zone is overlain by a piggyback stack of Penninic zone [Vollmayrand Wendt, 1987; Staubleand Pfiffner,199I]. and Austroalpinesedimentary nappes (Figure la). The Central Schlunegger et al. [1997b] reconstructed the two-dimen. Alps comprise a stack of north vergent Penninie and sional architecture of the central Swiss Molasse at ~25 Ma, us- Austroalpine sedimentary and crystalline nappes. They are ing the thicknessesand the sedimentologicaldata from anout. separatedfrom the south verging SouthernAlps [Schtnborn, crop section(Rigi) and three boreholes (Entlebuch-1,Boswil- 1992] by the mainly E-W striking Insubric Line (Figure la). 1, and Htinenberg-1; Figure 2). These authors demonstrated This suturepartly accommodatedthe identationof the Adriatic that at ~25 Ma the Molasse Basin consisted of two parts promontory by steep south directed synmagmatic reverse (northernand southernsedimentary domains) that are separated faulting and right-lateral strike-slip movements [Pfiffner, by a---5-km-wide floodplain (Figure 3). The southernmore 1992; Schmidet al., 1996] (Figure lb). proximalpart of the basinattained a restoredwidth of --20km The early Chattian (30-25 Ma) and partly the Rupelian (<30 and dippedas much as 6ø-7ø southat the Alpine thrustfront, Ma) depositsof central Switzerland,which
Recommended publications
  • Geological Excursion BASE-Line Earth
    Geological Excursion BASE-LiNE Earth (Graz Paleozoic, Geopark Karavanke, Austria) 7.6. – 9.6. 2016 Route: 1. Day: Graz Paleozoic in the vicinity of Graz. Devonian Limestone with brachiopods. Bus transfer to Bad Eisenkappel. 2. Day: Visit of Geopark Center in Bad Eisenkappel. Walk on Hochobir (2.139 m) – Triassic carbonates. 3. Day: Bus transfer to Mezica (Slo) – visit of lead and zinc mine (Triassic carbonates). Transfer back to Graz. CONTENT Route: ................................................................................................................................... 1 Graz Paleozoic ...................................................................................................................... 2 Mesozoic of Northern Karavanke .......................................................................................... 6 Linking geology between the Geoparks Carnic and Karavanke Alps across the Periadriatic Line ....................................................................................................................................... 9 I: Introduction ..................................................................................................................... 9 II. Tectonic subdivision and correlation .............................................................................10 Geodynamic evolution ...................................................................................................16 Alpine history in eight steps ...........................................................................................17
    [Show full text]
  • GSA Bulletin: Magnetostratigraphic Constraints on Relationships
    Magnetostratigraphic constraints on relationships between evolution of the central Swiss Molasse basin and Alpine orogenic events F. Schlunegger* Geologisches Institut, Universität Bern, Baltzerstrasse 1, CH-3012 Bern, Switzerland A. Matter } D. W. Burbank Department of Earth Sciences, University of Southern California, Los Angeles, California 90089-0740 E. M. Klaper Geologisches Institut, Universität Bern, Baltzerstrasse 1, CH-3012 Bern, Switzerland ABSTRACT thrusting along the eastern Insubric Line, sedimentary basins than in the adjacent fold- where >10 km of vertical displacement is inter- and-thrust belt, abundant stratigraphic research Magnetostratigraphic chronologies, to- preted. During the same time span, the Alpine has been done in foreland basins to assess the gether with lithostratigraphic, sedimentologi- wedge propagated forward along the basal evolutionary processes of the orogenic thrust cal, and petrological data enable detailed re- Alpine thrust, as indicated by the coarsening- wedge (Jordan et al., 1988; Burbank et al., 1986; construction of the Oligocene to Miocene and thickening-upward megasequence and by Burbank et al., 1992; Colombo and Vergés, history of the North Alpine foreland basin in occurrence of bajada fans derived from the 1992). Despite a more complete and better dated relation to specific orogenic events and ex- Alpine border. The end of this tectonic event is record within a foreland, the correlation of sedi- humation of the Alps. The Molasse of the study marked by a basinwide unconformity, inter- mentary events recorded in the foreland with tec- area was deposited by three major dispersal preted to have resulted from crustal rebound tonic events in the adjacent hinterland is com- systems (Rigi, Höhronen, Napf).
    [Show full text]
  • The Origin of Deep Geothermal Anomalies in the German Molasse Basin: Results from 3D Numerical Models of Coupled Fluid Flow and Heat Transport
    Originally published as: Przybycin, A. M., Scheck-Wenderoth, M., Schneider, M. (2017): The origin of deep geothermal anomalies in the German Molasse Basin: results from 3D numerical models of coupled fluid flow and heat transport. - Geothermal Energy, 5, 1. DOI: http://doi.org/10.1186/s40517-016-0059-3 Przybycin et al. Geotherm Energy (2017) 5:1 DOI 10.1186/s40517-016-0059-3 RESEARCH Open Access The origin of deep geothermal anomalies in the German Molasse Basin: results from 3D numerical models of coupled fluid flow and heat transport Anna M. Przybycin1,2*, Magdalena Scheck‑Wenderoth1,3 and Michael Schneider2 *Correspondence: anna. [email protected] Abstract 1 Department 6 The European Molasse Basin is a Tertiary foreland basin at the northern front of the Geotechnologies, Section 6.1 Basin Modelling, Alps, which is filled with mostly clastic sediments. These Molasse sediments are under‑ German Research lain by Mesozoic sedimentary successions, including the Upper Jurassic aquifer (Malm) Centre for Geosciences which has been used for geothermal energy production since decades. The thermal GFZ - Helmholtz Centre Potsdam, Telegrafenberg, field of the Molasse Basin area is characterized by prominent thermal anomalies. Since 14473 Potsdam, Germany the origin of these anomalies is still an object of debates, especially the negative ones Full list of author information represent a high risk for geothermal energy exploration. With our study, we want to is available at the end of the article contribute to the understanding of the thermal configuration of the basin area and with that help to reduce the exploration risk for future geothermal projects in the Molasse Basin.
    [Show full text]
  • New Aspects on the Timing of Deformation Along the South
    Originally published as: Bachmann, R., Glodny, J., Oncken, O., Seifert, W. (2009): Abandonment of the South Penninic-Austroalpine palaeosubduction zone, Central Alps, and shift from subduction erosion to accretion: constraints from Rb/Sr geochronology. - Journal of the Geological Society London, 166, 2, 217-231 DOI: 10.1144/0016-76492008-024. Abandonment of the South Penninic-Austroalpine palaeo-subduction zone, Central Alps, and shift from subduction erosion to accretion: constraints from Rb/Sr geochronology Raik Bachmann Deutsches GeoForschungsZentrum (GFZ), Telegrafenberg, 14473 Potsdam, Germany. [email protected] Present address: Horizon Energy Partners, Prinses Margrietplantsoen 81, 2595 BR The Hague, The Netherlands [email protected] Johannes Glodny Deutsches GeoForschungsZentrum (GFZ), Telegrafenberg, 14473 Potsdam, Germany, [email protected] Onno Oncken Deutsches GeoForschungsZentrum (GFZ), Telegrafenberg, 14473 Potsdam, Germany, [email protected] Wolfgang Seifert Deutsches GeoForschungsZentrum (GFZ), Telegrafenberg, 14473 Potsdam, Germany, [email protected] Corresponding author: Raik Bachmann 1 Abstract We present new age data for the evolution of the suture zone between lower-plate South Penninic and upper-plate Austroalpine units in the Central European Alps. Rb/Sr deformation ages for mylonitized rocks of the South Penninic palaeo-subduction mélange and for deformed Austroalpine basement (Eastern Switzerland) shed light on the pre-Alpine and Alpine deformation history along the suture, as well as on syn-subduction interplate mass transfer. Rb/Sr age data define two age groups. The first group reflects pre-Alpine events within the upper plate basement, with varying degree of resetting by subsequent Alpine overprints. The second group marks the waning of subduction-related deformation along the South Penninic-Austroalpine suture zone, at around 50 Ma, and termination at ~47 Ma.
    [Show full text]
  • Long-Wavelength Late-Miocene Thrusting in the North Alpine Foreland: Implications for Late Orogenic Processes
    Solid Earth, 11, 1823–1847, 2020 https://doi.org/10.5194/se-11-1823-2020 © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. Long-wavelength late-Miocene thrusting in the north Alpine foreland: implications for late orogenic processes Samuel Mock1, Christoph von Hagke2,3, Fritz Schlunegger1, István Dunkl4, and Marco Herwegh1 1Institute of Geological Sciences, University of Bern, Baltzerstrasse 1+3, 3012 Bern, Switzerland 2Institute of Geology and Palaeontology, RWTH Aachen University, Wüllnerstrasse 2, 52056 Aachen, Germany 3Department of Geography and Geology, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria 4Geoscience Center, Sedimentology and Environmental Geology, University of Göttingen, Goldschmidtstrasse 3, 37077 Göttingen, Germany Correspondence: Samuel Mock ([email protected]) Received: 17 October 2019 – Discussion started: 27 November 2019 Revised: 24 August 2020 – Accepted: 25 August 2020 – Published: 13 October 2020 Abstract. In this paper, we present new exhumation ages 1 Introduction for the imbricated proximal molasse, i.e. Subalpine Mo- lasse, of the northern Central Alps. Based on apatite .U−Th−Sm/=He thermochronometry, we constrain thrust- Deep crustal processes and slab dynamics have been con- driven exhumation in the Subalpine Molasse between 12 and sidered to influence the evolution of mountain belts (e.g. 4 Ma. This occurs synchronously to the main deformation in Davies and von Blanckenburg, 1995; Molnar et al., 1993; the adjacent Jura fold-and-thrust belt farther north and to the Oncken et al., 2006). However, these deep-seated signals late stage of thrust-related exhumation of the basement mas- may be masked by tectonic forcing at upper-crustal levels sifs (i.e.
    [Show full text]
  • Late Miocene Thrusting in the North Alpine Foreland
    Solid Earth Discuss., https://doi.org/10.5194/se-2019-56 Manuscript under review for journal Solid Earth Discussion started: 20 March 2019 c Author(s) 2019. CC BY 4.0 License. Late Miocene thrusting in the North Alpine foreland: Driven by a deep-seated process and shaped by the local mechanical stratigraphy Samuel Mock1, Christoph von Hagke2, Fritz Schlunegger1, István Dunkl3, Marco Herwegh1 1Institute of Geological Sciences, University of Bern, Baltzerstrasse 1+3, 3012 Bern, Switzerland 5 2Institute of Geology and Palaeontology, RWTH Aachen University Wüllnerstrasse 2, 52056 Aachen, Germany 3Geoscience Center, Sedimentology and Environmental Geology, University of Göttingen Goldschmidtstrasse 3, 37077 Göttingen, Germany Correspondence to: Samuel Mock ([email protected]) Abstract. Besides classical emplacement and accretion related nappe tectonics, the Oligocene to middle Miocene post- 10 collisional evolution of the central European Alps was also characterized by pronounced vertically directed tectonics. These are expressed by backthrusting along the Insubric Line and the subsequent uplift of the External Crystalline Massifs (ECMs). During late Miocene times, the Central Alps experienced lateral growth when deformation propagated into the external parts of both the pro- and retro-side of the orogen. For the North Alpine foreland, pro-wedge propagation of deformation has been kinematically and spatially linked to the uplift and exhumation of the ECMs. In this paper, we investigate the young 15 exhumation history of the North Alpine foreland. Based on low-temperature apatite (U-Th-Sm)/He thermochronometry, we constrain thrusting in the Subalpine Molasse between 12 Ma and 5 Ma, thus occurring coeval to the main deformation phase in the adjacent Jura fold-and-thrust belt (FTB) and late stage exhumation of the ECMs.
    [Show full text]
  • Disentangling Between Tectonic, Eustatic and Sediment Flux Controls on the 20 Ma-Old Burdigalian Transgression of the Molasse Basin in Switzerland
    Disentangling between tectonic, eustatic and sediment flux controls on the 20 Ma-old Burdigalian transgression of the Molasse basin in Switzerland 5 Philippos Garefalakis1, Fritz Schlunegger1 1Institute of Geological Sciences, University of Bern, Bern, CH-3012, Switzerland Correspondence to: Philippos Garefalakis ([email protected]) Abstract 10 The stratigraphic architecture of the Swiss Molasse basin, situated on the northern side of the evolving Alps, reveals crucial information about the basin’s geometry, its evolution and the processes leading to the deposition of the siliciclastic sediments. Nevertheless, the formation of the Upper Marine Molasse and the controls on the related Burdigalian transgression have still been a matter of scientific debate. During the time period from c. 20 to 17 Ma, the Swiss Molasse basin was partly flooded by a shallow marine sea, striking SW – NE. We conducted sedimentological and stratigraphic analyses of several sites across the 15 entire Swiss Molasse basin. An attempt is made to extract stratigraphic signals that can be related to changes in sediment supply rate, variations in the eustatic sea level and subduction tectonics. Field investigations show that the transgression and the subsequent evolution of the Burdigalian seaway was characterized by (i) changes in sediment transport directions, (ii) a deepening and widening of the basin, and (iii) phases of erosion and non- deposition. We use these changes in the stratigraphic record to disentangle between tectonic and surface controls at various 20 scales. As the most important mechanism, roll-back subduction of the European mantle lithosphere and delamination of crustal material most likely explain the widening of the Molasse basin particularly at distal sites.
    [Show full text]
  • Deformation Along the Roof of a Fossil Subduction Interface in the Transition Zone Below Seismogenic Coupling: the Austroalpine GEOSPHERE; V
    Research Paper THEMED ISSUE: Subduction Top to Bottom 2 GEOSPHERE Deformation along the roof of a fossil subduction interface in the transition zone below seismogenic coupling: The Austroalpine GEOSPHERE; v. 16, no. 2 case and new insights from the Malenco Massif (Central Alps) https://doi.org/10.1130/GES02149.1 Paraskevi Io Ioannidi1, Samuel Angiboust1,2, Onno Oncken1, Philippe Agard3, Johannes Glodny1, and Masafumi Sudo4 11 figures; 5 tables; 1 set of supplemental files 1GFZ German Research Centre for Geosciences, D-14473 Potsdam, Germany 2Université de Paris, Institut de Physique du Globe de Paris, Centre National de la Recherche Scientifique (CNRS), F-75005 Paris, France 3 CORRESPONDENCE: [email protected] Institut des Sciences de la Terre de Paris (ISTeP)–Unité Mixte de Recherche (UMR) 7193, Sorbonne Université, F-75005 Paris, France 4Institut für Geowissenschaften, Universität Potsdam, 14476 Potsdam, Germany CITATION: Ioannidi, P.I., Angiboust, S., Oncken, O., Agard, P., Glodny, J., and Sudo, M., 2020, Deforma- tion along the roof of a fossil subduction interface in ABSTRACT the frame of previous studies on other segments documented thanks to a wealth of well-exposed the transition zone below seismogenic coupling: The of the same Alpine paleosubduction interface, key localities (Kitamura et al., 2005; Vannucchi Austroalpine case and new insights from the Malenco Massif (Central Alps): Geosphere, v. 16, no. 2, p. 510– A network of fossil subduction plate inter- and we propose that this system of shear zones et al., 2008; Bachmann et al., 2009b; Rowe et al., 532, https://doi.org/10.1130/GES02149.1. faces preserved in the Central Alps (Val Malenco, represents deformation conditions along the sub- 2013), our understanding of deeper deformation N Italy) is herein used as a proxy to study defor- duction interface(s) in the transition zone below processes (20–40 km depth) is hampered by the Science Editor: Shanaka de Silva mation processes related to subduction and the seismogenic zone during active subduction.
    [Show full text]
  • Geology of Nepal and Its Regional Frame
    J. geol. SOC. London, vol. 137, 1980, pp. 1-34, 15 figs. Printed in Northern Ireland. Geology of Nepal and its regional frame J. Stocklin Thirty-third William Smith Lecture CONTENTS 1. Introduction 3 a. General background 3 b. Zonation of Nepal Himalaya 3 2. The High Himalaya 4 a. Central Crystalline zone 4 (i) Composition and stratigraphy 4 (ii) Structure 5 (iii) Metamorphism, granitization, and the basement problem 5 b. Tibetan sedimentary zone 6 (i) Stratigraphy 6 (ii) Structure 7 c. Indus-Tsangpo suture zone 7 3. The Lesser Himalaya 9 a. ‘The unpaged historic manuscript’ 9 b. Palaeontological evidence 9 c. Stratigraphical implications 11 d. The Kumaon background in western Nepal 11 (i) The sedimentary belts 11 (ii) The crystalline ‘klippen’ 13 e. The Sikkim background in eastern Nepal 13 f. New studies in Central Nepal 15 (i) General aspects 15 (ii) The Nawakot Complex 18 (iii) The Kathmandu Complex 19 (iv) Metamorphism and granitization 21 (v) Autochthony or allochthony? 22 (vi) Mahabharat Thrust and Kathmandu nappe 22 g. Reverse metamorphism and Main Central Thrust 24 h. Main Boundary Thrust, Siwalik belt, and Gangetic plain 25 4. Regional aspects 26 a. Palaeogeography 26 b. The Himalaya in the structure of Central Asia 27 c.Eurasia/Gondwana relations 30 S. References 31 SUMMARY: Since the opening of Nepal in 1950, a wealth of new information on the geology of the Himalaya has emanated from this country. The sedimentary history of the Range is mostreliably recorded in the richlyfossiliferous ‘Tethyan’ or ‘Tibetan’ zone, which extends to the N from the summit region and has revealed an epicontinental to miogeosynclinal sequence, over 10 km thick, ranging from Cambrian to Cretaceous.
    [Show full text]
  • Geomol – Assessing Subsurface Potentials of the Alpine Foreland Basins for Sustainable Planning and Use of Natural Resources Project Report
    Bayerisches Landesamt für Umwelt GeoMol – Assessing subsurface potentials of the Alpine Foreland Basins for sustainable planning and use of natural resources Project Report Bayerisches Landesamt für Umwelt GeoMol – Assessing subsurface potentials of the Alpine Foreland Basins for sustainable planning and use of natural resources Project Report The GeoMol Team (2015) Imprint GeoMol – Assessing subsurface potentials of the Alpine Foreland Basins for sustainable planning and use of natural resources. Project Report Publisher: Bayerisches Landesamt für Umwelt (LfU) Bavarian Environment Agency Bürgermeister-Ulrich-Straße 160 86179 Augsburg phone: 0821 9071-0 fax: 0821 9071-5556 e-mail: [email protected] website: www.lfu.bayern.de Authors: The GeoMol Team (2015) Gerold W. Diepolder1 (editor in chief), Robin Allenbach2, Roland Baumberger2, Magdalena Bottig3, Agnès Brenot4, Anna Katharina Brüstle3, Alessandro Cagnoni5, Laure Capar4, Renaud Couëffé4, Chiara d’Ambrogi6, Chrystel Dezayes4, Mirjam Dürst Stucki2, Charlotte Fehn7, Fernando Ferri6, Sunsearé Gabalda4, Paul Gabriel8, Jan Gietzel8, Gregor Götzl3, Katja Koren9, Pascal Kuhn2, Eva Kurmann-Matzenauer2, Andrej Lapanje9, Simon Lopez4, Francesco Emanuele Maesano6, Stéphane Marc4, Salomè Michael2, Fabio Carlo Molinari10, Edgar Nitsch7, Robert Pamer1, Sebastian Pfleiderer3, Andrea Piccin5, Maria Ponzio2, Dušan Rajver9, Lance Reynolds2, Igor Rižnar9, Nina Rman9, Isabel Rupf7, Uta Schulz1, Stephan Sieblitz1, Helmut Schaeben8, Dejan Šram9, Giulio Torri10, Gunther Wirsing7, Heiko Zumsprekel7.
    [Show full text]
  • A Partial Glossary of Spanish Geological Terms Exclusive of Most Cognates
    U.S. DEPARTMENT OF THE INTERIOR U.S. GEOLOGICAL SURVEY A Partial Glossary of Spanish Geological Terms Exclusive of Most Cognates by Keith R. Long Open-File Report 91-0579 This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. 1991 Preface In recent years, almost all countries in Latin America have adopted democratic political systems and liberal economic policies. The resulting favorable investment climate has spurred a new wave of North American investment in Latin American mineral resources and has improved cooperation between geoscience organizations on both continents. The U.S. Geological Survey (USGS) has responded to the new situation through cooperative mineral resource investigations with a number of countries in Latin America. These activities are now being coordinated by the USGS's Center for Inter-American Mineral Resource Investigations (CIMRI), recently established in Tucson, Arizona. In the course of CIMRI's work, we have found a need for a compilation of Spanish geological and mining terminology that goes beyond the few Spanish-English geological dictionaries available. Even geologists who are fluent in Spanish often encounter local terminology oijerga that is unfamiliar. These terms, which have grown out of five centuries of mining tradition in Latin America, and frequently draw on native languages, usually cannot be found in standard dictionaries. There are, of course, many geological terms which can be recognized even by geologists who speak little or no Spanish.
    [Show full text]
  • The Tauern Window (Eastern Alps, Austria): a New Tectonic Map, with Cross-Sections and a Tectonometamorphic Synthesis
    Swiss J Geosci (2013) 106:1–32 DOI 10.1007/s00015-013-0123-y The Tauern Window (Eastern Alps, Austria): a new tectonic map, with cross-sections and a tectonometamorphic synthesis Stefan M. Schmid • Andreas Scharf • Mark R. Handy • Claudio L. Rosenberg Received: 31 August 2012 / Accepted: 11 March 2013 Ó Swiss Geological Society 2013 Abstract We present a tectonic map of the Tauern Window pressure overprint of some of the units of the Tauern Window, and surrounding units (Eastern Alps, Austria), combined with has a long history, starting in Turonian time (around 90 Ma) a series of crustal-scale cross-sections parallel and perpen- and culminating in Lutetian to Bartonian time (45–37 Ma). dicular to the Alpine orogen. This compilation, largely based on literature data and completed by own investigations, Keywords Alpine tectonics Á Metamorphism Á reveals that the present-day structure of the Tauern Window Age dating Á Orogenesis Á Lithosphere dynamics is primarily characterized by a crustal-scale duplex, the Venediger Duplex (Venediger Nappe system), formed during the Oligocene, and overprinted by doming and lateral extru- 1 Introduction sion during the Miocene. This severe Miocene overprint was most probably triggered by the indentation of the Southalpine The Tauern Window of the Eastern Alps exposes exhumed Units east of the Giudicarie Belt, initiating at 23–21 Ma and parts of Europe-derived crust that were accreted to the base of linked to a lithosphere-scale reorganization of the geometry an Adria-derived upper plate, represented today by the of mantle slabs. A kinematic reconstruction shows that Austroalpine nappes (e.g., Schmid et al.
    [Show full text]