DOCSLIB.ORG

BASEMENT SEISMICITY BENEATH the ANDEAN PRECORDILLERA THIN&Hyphen

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
BASEMENT SEISMICITY BENEATH the ANDEAN PRECORDILLERA THIN&Hyphen TEC'rO••, VOL. 12, NO. 1, PAGES 63-76, FEBRUARY 1993 BASEMENT SEISMICITY BENEATH THE by subductionof the oceanic Nazca plate beneath the ANDEAN PRECORDILLERA THIN- continentalSouth American plate. The modernAndes are due SKINNED THRUST BELT AND to Neogene tectonics characterized by along-strike IMPLICATIONS FOR CRUSTAL AND segmentationof majorfeatures of thesubducted and overriding LITHOSPHERIC BEHAVIOR plates [Barazangiand Isacks, 1976; Jordan et al., 1983] (Figures1 and2). In addition,the along-strikefeatures of the Robert Smalley,Jr., 1 Jos6Pujol, 1 MarcRegnier, 2 two platesare correlated,both spatiallyand in their temporal Jer-MingChiu, 1 Jean-LucChatelain, 2,3Bryan L. Isacks,4 development.Between 15øS and 24øS the Altiplano-Puna MarioAraujo, 5 and N. Puebla5 plateau, the EasternCordillera and SubandeanZone thrust belts,and an activevolcanic arc are located above a moderately Abstract.Data froma digitallyrecording seismic network dippingWadati-Benioff zone (WBZ). In contrast,a narrow in SanJuan, Argentina, provide the first imagesof crustal thin-skinned thrust belt (lyecordillera), a wide zone of scalebasement faults beneath the lyecordillera. This seismicity basementuplifts (SierrasPampeanas), and an extinctare are is nearthe boundary between the lyecordillera (a thin-skinned locatedabove an intermediate-depthsubhorizontally subducting thrustbelt) and the SierrasPampeanas (a regionof thick- WBZ between 28øS and 33øS. Shutdownof volcanism, onset skinnedbasement deformation), two seismically active tectonic of Pampean and Precordilleran crustal deformation, and provincesof theAndean foreland. The seismicity data support developmentof flat subductionare thoughtto coincide at modelsfor thisregion in whichcrustal thickening, rather than 10-15Ma [Jordanet al., 1983]. The SierrasPampeanas and magmaticaddition or thermaluplift, plays the dominant the lYecordilleraare thoughtto have a tectonicrelationship mountainbuilding role. The lYecordillera seismicity occurs in similarto thatof theMesozoic Sevier and Laramide provinces three segmentsdistributed north to south.The southern of North America,which are alsothought to havedeveloped segmentis an areaof diffuseactivity extending across the overa regionof flat subduction[Dickenson and Snyder, 1978; Precordilleraand eastwardinto the SierrasPampeanas that Fieldingand Jordan, 1988]. showsno patternsin mapor crosssection. The northernand The Andeanorogen is seismicallyactive, and variations of centralsegments have well-defined dipping planes that define crustalintraplate seismicity in the overridingplate correlate crustalscale faults extending from 5 to 35 km depth.It is with the along-strikevariations of tectonicstyle (Figure2). clear from the relativefault geometriesthat the overlying Crustalseismicity is concentratedin a narrowband along the Precordillerais not simplyrelated to the basementactivity. easternmargin of theforeland in areasover normal subduction, Theseismicity here may result from reactivation of anancient while above flat subductiona wide area of the foreland, with suturebetween the lYecordillera and Pampeanas terranes or be thin- and thick-skinnedtectonic provinces, is highly active occurringin basementof unknownaffinity west of thesuture. seismically.The easternmostlimit of crustal seismicity Theseismicity provides the first constraints on basement fault coincideswith the easternmostWBZ activityin bothflat and geometries,and we present models integrating this information steepsubduction regions. The depthof crustalearthquakes also with the surfacegeology. These basement faults may have correlateswith tectonicstyle. In regionsof normalsubduction, been responsiblefor the 1944 Ms 7.4 earthquakethat seismicityoccurs in the upper and mid crust to depthsof destroyedthe city of SanJuan. The imagingof thesefaults 25 km [Cahill et al., 1992], while in areasof flat subduction suggeststhat seismic risk estimates for SanJuan made on the crustalevents occur at mid and lower crustaldepths to 40 km basisof surfacegeologic studies may be too low. ISmalleyand Isacks,1990; Su•ez et al., 1983].This variation may be due to regionaldifferences in lithosphericor crustal INTRODUCTION stress,strain rate, crustalgeotherm, or rheology,both across andalong the orogen. The Andesprovide a uniquelaboratory to studymountain belt formation in a subduction-driven but noncollisional GEOLOOY environment.The presentorogen began in theJurassic, driven Precordillera. The lYecordillera is a thin-skinned thrust belt of Paleozoicelastics divided into three structural subprovinces: 1 Centerfor Earthquake Research and Information, Memphis Western,Central, and Eastern(Figure 3) [Baldis,1975; Ortiz StateUniversity, Memphis, TN. and Zambrano, 1981; Baldis et al., 1982]. The Central and 2 InstitutFranqais de RechercheScientifique pour le Westernprovinces form the forelandthrust belt foundon the D6veloppementen CoopdrationNoumea, New Caledonia, cratonicside of compressionalorogens. These mountain belts South West Pacific. are interpretedas the resultof a crustalshortening across an 3 Nowat Institut Franqais deRecherche Scientifique pour le orogenin which crustalthickening associated with A-type D6veloppementen Coop6ration,Domaine Universitaire, subductionoccurs along a majorintracontinental thrust [Bally, Grenoble,France. 1981]. Crustalmaterial from the orogenproper is thrust 4 Institutefor the Studyof the Continents,Cornell cratonwardover relatively undeformedforeland basement, University,Ithaca, New York. pushingthe forelandbasin sediments into a thin-skinnedthrust 5 InstitutoNacional de Prevenci6nSfsmica, San Juan, belt. This thrustbelt is typicallythe cratonwardmostlimit of Argentina. deformation associatedwith an orogenic system. The developmentof thesethrust belts generally follows a set of Copyfight1993 by the AmeficanGeophysical Union. rules, derived from geologic studies [Chappie, 1978; Dahlstrom,1970; Davis et al., 1983]and physical models of Paper number92TC01108. deformation[Panian and Pilant, 1990] describing the spatial 0278-7407/93/92TC-01108510.00 andtemporal evolution of their structures. 64 Smalleyet al.: BasementSeismicity in AndeanPrecordillera 20 S 25 30 75 W 7O 65 Fig. 1. Map of westernSouth America illustrating upper plate tectonic features, volcanic arc, and contours of theWadati-Benioff zone (WBZ). Along-strikesegmentation of the upperplate tectonic provinces correlateswith the along-strike segmentation of the WBZ [Jordanet al., 1983].The distribution of Neogene volcanoes(open circles) [Isacks, 1988] shows an active magmatic arc over the steep WBZ segmentand the absenceof anactive arc over the flat segment. The drainage divide, which defines the internally drained Puna/Altiplanoplateau and then follows the crest of theAndes southward between the Principal and Frontal cordilleras,is also shown. The inset shows the major topographic features of theoceanic Nazca plate (Juan Fernandezand Nazca ridges). 20 S 25 30 o o 75 W 70 65 Fig. 2. Shallowintraplate seismicity (solid circles) and damaging historic earthquakes (open circles) [Zamarbideand Castano,1978] of the Andeanback-arc. Epicenters are selectedfrom Preliminary Determinationof Epicenters(1963, 1983-1990)and International Seismological Center (1964-1982) catalogs.Selected events were located with 15or moreP arrivals,are shallower than 50 km,and are east of the 100km WBZ contourensuring they are in SouthAmerican lithosphere and are notinterplate or WBZ events.A selectionof focal mechanisms[Chinn and Isacks,1983; Dziewonski et al., 1987; Kadinsky-Cade, 1985;Stauder, 1973] is alsoshown. The level of seismicityin thePie dePalo area (31.5øS, 67.5øW) is so intensethat only focalmechanisms with accuratesource depths from syntheticmodeling are shown. Tectonicprovinces and inset are as in Figure1. 66 Smalleyet al.: BasementSeismicity in AndeanPrecordillera 894 .2 31 [] 1977 6.7 7A 32 Okm 50km Salinas i i 69 W 68 67 Fig.3. Geology,mapped and inferred faults (solid and dotted bold lines), seismic station sites (small triangles:solid for stations, open for arrays of 8 to 11stations with apertures of 1 m to 1 km),damaging historicalseismicity (dated open squares, 1944 location from Kadinsky-Cade [1985]), the 1944earthquake intensityVIII isoseismal(large triangle outline) [Castellanos, 1945], and two LANDSAT lineaments in SanJuan (heavy gray lines). The LANDSAT lineament near La Lajaincludes the fault suffering offset in 1944.Mountain range patterns are light gray for sedimentaryrocks (Precordillera) and dark gray for basementblocks (Sierras Pampeanas); intermontane valleys are in white.The Eastern Precordillera is the chainof mountainseast of the MatagusanosValley (SierrasChica de Zonda,Villicum, Morado, and extensionsnorth and south). West of thePrecordillera are the Calingasta and Iglesia valleys. The CentralPrecordillera is a typicalforeland thin-skinned Pampeanas,a province of Precambrianmetamorphic basement thrust belt. The Eastern Precordillera was fu'st described as the block uplifts [Caminoset al., 1982; Cingolaniand Varela, easternmostpart of this thrust belt [Orfiz and Zambrano, 1975]. Such deformationcratonward of the thin-skinnedthrust 1981], but it appearsto break two rules of thin-skinned belt is unusualand found only in regions overlying thrusting.First, the EasternPrecordillera is thrustwestward, subhorizontalsubducfion, a correlation also thought to holdin away from the craton.Second, the basalunit of the Eastern extinctorogens [Dickenson and Snyder, 1978]. The Pampeanas Precordillerais over 2 km down-sectionwith respectto the
Load more

Recommended publications
  • Geologic Storage Formation Classification: Understanding Its Importance and Impacts on CCS Opportunities in the United States
    BEST PRACTICES for: Geologic Storage Formation Classification: Understanding Its Importance and Impacts on CCS Opportunities in the United States First Edition Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed therein do not necessarily state or reflect those of the United States Government or any agency thereof. Cover Photos—Credits for images shown on the cover are noted with the corresponding figures within this document. Geologic Storage Formation Classification: Understanding Its Importance and Impacts on CCS Opportunities in the United States September 2010 National Energy Technology Laboratory www.netl.doe.gov DOE/NETL-2010/1420 Table of Contents Table of Contents 5 Table of Contents Executive Summary ____________________________________________________________________________ 10 1.0 Introduction and Background
    [Show full text]
  • Map: Basement-Cover Relationships
    Downloaded from http://sp.lyellcollection.org/ by guest on September 30, 2021 • BASEMENT-COVER RELATIONSHIPS Downloaded from http://sp.lyellcollection.org/ by guest on September 30, 2021 BASEMENT-COVER RELATIONSHIPS FLINN ET AL~g~ JOHNSTONE ET AL RATHBONE ~ HARRIS~'~ RAMSAY & STURT SANDERSi I & VAN BREEMEN BREWER ET AL" 0 km 100 I I WATSON & DUNNING- GENERAL REVIEW KENNAN ET AL-- PARATECTONIC IRELAND BAMFORD-- SEISMIC CONSTRAINTS Downloaded from http://sp.lyellcollection.org/ by guest on September 30, 2021 The Caledonides of the British Isles--reviewed. 1979. Geological Society of London. Basement-cover relations in the British Caledonides Janet Watson & F. W. Dunning CONTENTS 1. Introduction 67 2. The Metamorphic Caledonides 68 a The Lewisian complex and related rocks 68 b Pre-Caledonian cover units 70 c Other possible basement units 72 d The Caledonian orogenic front 73 e Grenville activity in the northern Caledonian province 74 3. The Non-metamorphic Caledonides 76 a Basic facts relating to the belt in general 76 b The Midland Valley Transition Zone 77 c The Southern Uplands-Longford-Down-Clare Inliers Belt 83 d The Iapetus Suture 84 e The Lake District-Isle of Man-Leinster Belt 84 f The Irish Sea Horst 85 g The Welsh Basin and its eastern borders 85 h Eastern England 86 j The Midland Craton 86 4. Conclusions 87 5. Acknowledgements 88 6. References 88 1. Introduction underlying the Metamorphic Caledonides (which Although the conventional regional subdivi- consists mainly of gneisses) and that underlying sion of the British and Irish
    [Show full text]
  • Basement Characteristic Western Part of Java, Indonesia
    Vol.8 (2018) No. 5 ISSN: 2088-5334 Basement Characteristic Western Part of Java, Indonesia; Case Study in Bayah Area, Banten Province Aton Patonah# , Haryadi Permana* #Faculty of Geological Engineering, Padjadjaran University, Sumedang KM 21. Jatinangor, 45363, West Java, Indonesia E-mail: [email protected] *Research Center for Geotechnology LIPI, Jl Sangkuriang Bandung 40135, West Java, Indonesia E-mail: [email protected] Abstract — Recent study reveals that in Bayah Complex, 20 km west of Ciletuh Melange Complex, discovered a metamorphic rock that interpreted as the basement of Java. This research aims to know the characteristic of metamorphic in Bayah areas. The result shows that the metamorphic rocks of Bayah Geological Complex are dominated by mica schist group, i.e., muscovite schist, muscovite-biotite schist, garnet biotite schist and chlorite schist associated with Pelitic - Psammitic protolith. The amphibolite, epidote amphibolite and actinolite schist found were metamorphosed of mafic rock protolith. All of them have been deformed and altered. Based on mineral assemblage, mica schist group included lower greenschist - epidote-amphibolite facies, whereas actinolite schist, epidote amphibolite schist, and hornblende schist included greenschist facies, epidote-amphibolite facies, and amphibolite facies respectively. Based on the data, these metamorphic rocks are associated with the orogenic style. The metamorphic rocks exposed to the surface through a complex process since Late Cretaceous. Metamorphic rocks have been deformed, folded and faulted since its formation. Its possible this rock was uplifted to the surface due to the intrusion of Cihara Granodiorite. Keywords — Bayah Geological Complex; greenschist facies; amphibolite facies; orogenic style; uplifted. [12]. According to [11], metamorphic rocks that exposed in I.
    [Show full text]
  • Part 629 – Glossary of Landform and Geologic Terms
    Title 430 – National Soil Survey Handbook Part 629 – Glossary of Landform and Geologic Terms Subpart A – General Information 629.0 Definition and Purpose This glossary provides the NCSS soil survey program, soil scientists, and natural resource specialists with landform, geologic, and related terms and their definitions to— (1) Improve soil landscape description with a standard, single source landform and geologic glossary. (2) Enhance geomorphic content and clarity of soil map unit descriptions by use of accurate, defined terms. (3) Establish consistent geomorphic term usage in soil science and the National Cooperative Soil Survey (NCSS). (4) Provide standard geomorphic definitions for databases and soil survey technical publications. (5) Train soil scientists and related professionals in soils as landscape and geomorphic entities. 629.1 Responsibilities This glossary serves as the official NCSS reference for landform, geologic, and related terms. The staff of the National Soil Survey Center, located in Lincoln, NE, is responsible for maintaining and updating this glossary. Soil Science Division staff and NCSS participants are encouraged to propose additions and changes to the glossary for use in pedon descriptions, soil map unit descriptions, and soil survey publications. The Glossary of Geology (GG, 2005) serves as a major source for many glossary terms. The American Geologic Institute (AGI) granted the USDA Natural Resources Conservation Service (formerly the Soil Conservation Service) permission (in letters dated September 11, 1985, and September 22, 1993) to use existing definitions. Sources of, and modifications to, original definitions are explained immediately below. 629.2 Definitions A. Reference Codes Sources from which definitions were taken, whole or in part, are identified by a code (e.g., GG) following each definition.
    [Show full text]
  • Pan-African Orogeny 1
    Encyclopedia 0f Geology (2004), vol. 1, Elsevier, Amsterdam AFRICA/Pan-African Orogeny 1 Contents Pan-African Orogeny North African Phanerozoic Rift Valley Within the Pan-African domains, two broad types of Pan-African Orogeny orogenic or mobile belts can be distinguished. One type consists predominantly of Neoproterozoic supracrustal and magmatic assemblages, many of juvenile (mantle- A Kröner, Universität Mainz, Mainz, Germany R J Stern, University of Texas-Dallas, Richardson derived) origin, with structural and metamorphic his- TX, USA tories that are similar to those in Phanerozoic collision and accretion belts. These belts expose upper to middle O 2005, Elsevier Ltd. All Rights Reserved. crustal levels and contain diagnostic features such as ophiolites, subduction- or collision-related granitoids, lntroduction island-arc or passive continental margin assemblages as well as exotic terranes that permit reconstruction of The term 'Pan-African' was coined by WQ Kennedy in their evolution in Phanerozoic-style plate tectonic scen- 1964 on the basis of an assessment of available Rb-Sr arios. Such belts include the Arabian-Nubian shield of and K-Ar ages in Africa. The Pan-African was inter- Arabia and north-east Africa (Figure 2), the Damara- preted as a tectono-thermal event, some 500 Ma ago, Kaoko-Gariep Belt and Lufilian Arc of south-central during which a number of mobile belts formed, sur- and south-western Africa, the West Congo Belt of rounding older cratons. The concept was then extended Angola and Congo Republic, the Trans-Sahara Belt of to the Gondwana continents (Figure 1) although West Africa, and the Rokelide and Mauretanian belts regional names were proposed such as Brasiliano along the western Part of the West African Craton for South America, Adelaidean for Australia, and (Figure 1).
    [Show full text]
  • Precambrian Basement Terrane of South Dakota
    BULLETIN 41 Precambrian Basement Terrane of South Dakota KELLI A. MCCORMICK Department of Environment and Natural Resources Geological Survey Program Akeley-Lawrence Science Center University of South Dakota Vermillion, South Dakota 2010 GEOLOGICAL SURVEY PROGRAM DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES AKELEY-LAWRENCE SCIENCE CENTER, USD 414 EAST CLARK STREET VERMILLION, SOUTH DAKOTA 57069-2390 (605) 677-5227 Derric L. Iles, M.S., C.P.G. State Geologist Sarah A. Chadima, M.S., C.P.G. Senior Geologist Daniel E. Costello, M.S. Geologist Timothy C. Cowman, M.S. Natural Resources Administrator Brian A. Fagnan, M.S. Senior Geologist Dragan Filipovic, M.S. Senior Hydrologist Ann R. Jensen, B.S. Senior Geologist Darren J. Johnson, M.S. Geologist Matthew T. Noonan, B.S. Hydrologist Thomas B. Rich, M.S. Senior Hydrologist Layne D. Schulz, B.S. Senior Geologist Dennis D. Iverson Civil Engineering Technician Scott W. Jensen Civil Engineering Technician Ted R. Miller, B.S. Civil Engineering Technician Colleen K. Odenbrett Word Processing Supervisor Jeffrey J. Puthoff, B.A. Natural Resources Technician Lori L. Roinstad Cartographer Priscilla E. Young, B.S. Senior Secretary RAPID CITY REGIONAL OFFICE 2050 WEST MAIN, SUITE 1 RAPID CITY, SOUTH DAKOTA 57702-2493 (605) 394-2229 Mark D. Fahrenbach, Ph.D. Senior Geologist Kelli A. McCormick, Ph.D. Senior Geologist Joanne M. Noyes, M.S., P.E. Senior Hydrologist STATE OF SOUTH DAKOTA M. Michael Rounds, Governor DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES Steven M. Pirner, Secretary DIVISION OF FINANCIAL AND TECHNICAL ASSISTANCE David Templeton, Director GEOLOGICAL SURVEY PROGRAM Derric L. Iles, State Geologist BULLETIN 41 PRECAMBRIAN BASEMENT TERRANE OF SOUTH DAKOTA KELLI A.
    [Show full text]
  • Field Trip - Alps 2013
    Student paper Field trip - Alps 2013 Evolution of the Penninic nappes - geometry & P-T-t history Kevin Urhahn Abstract Continental collision during alpine orogeny entailed a thrust and fold belt system. The Penninic nappes are one of the major thrust sheet systems in the internal Alps. Extensive seismic researches (NFP20,...) and geological windows (Tauern-window, Engadin-window, Rechnitz-window), as well as a range of outcrops lead to an improved understanding about the nappe architecture of the Penninic system. This paper deals with the shape, structure and composition of the Penninic nappes. Furthermore, the P-T-t history1 of the Penninic nappes during the alpine orogeny, from the Cretaceous until the Oligocene, will be discussed. 1 The P-T-t history of the Penninic nappes is not completely covered in this paper. The second part, of the last evolution of the Alpine orogeny, from Oligocene until today is covered by Daniel Finken. 1. Introduction The Penninic can be subdivided into three partitions which are distinguishable by their depositional environment (PFIFFNER 2010). The depositional environments are situated between the continental margin of Europe and the Adriatic continent (MAXELON et al. 2005). The Sediments of the Valais-trough (mostly Bündnerschists) where deposited onto a thin continental crust and are summarized to the Lower Penninic nappes (PFIFFNER 2010). The Middle Penninic nappes are comprised of sediments of the Briançon-micro-continent. The rock compositions of the Lower- (Simano-, Adula- and Antigori-nappe) and Middle- Penninic nappes (Klippen-nappe) encompass Mesozoic to Cenozoic sediments, which are sheared off from their crystalline basement. Additionally crystalline basement form separate nappe stacks (PFIFFNER 2010).
    [Show full text]
  • Age of the Basement Rocks of Southwest Montana
    Age of the basement rocks of southwest Montana H. L. JAMES U.S. Geological Survey, Port Townsend, Washington 98368 C. E. HEDGE U.S. Geological Survey, Denver, Colorado 80225 ABSTRACT 113 m.y. Inclusion of other published data in Wyoming and Montana. The exposed for the Tobacco Root Range yields a best-fit rocks have complex histories, and the Rb-Sr analyses of a suite of quartzo- value of 2,730 ± 85 m.y. This age corre- questions of true ages and age relations are feldspathic gneisses that are interlayered sponds closely to that of the principal only gradually yielding to attack by isotopic with beds of marble, quartzite, and am- metamorphic-plutonic epoch of the Bear- dating. This paper is concerned mainly with phibolite in the Ruby and Tobacco Root tooth Mountains, to which the term "Bear- the results and implications of Rb-Sr Ranges and the Gallatin River canyon of tooth orogeny" has been applied. It also analyses of a suite of samples of quartzo- southwest Montana show that the age of demonstrates that the major Precambrian feldspathic gneiss from the Ruby Range, the metamorphism of these strata occurred metasedimentary sequences of the region Tobacco Root Range, and the Gallatin about 2,750 m.y. ago. The 13 samples are of Archean age. River canyon area (Fig. 1). analyzed are from rock units that have in the past been assigned stratigraphically to INTRODUCTION GEOLOGY the Pony Group, Cherry Creek Group, and Dillon Granite Gneiss. Except for two Precambrian rocks of pre-Belt age — that General Outline samples of anomalous composition, the is, older than about 1,400 m.y.
    [Show full text]
  • Deep Structure, Tectonics and Petroleum Potential of the Western Sector of the Russian Arctic
    Journal of Marine Science and Engineering Article Deep Structure, Tectonics and Petroleum Potential of the Western Sector of the Russian Arctic Alexey S. Egorov 1, Oleg M. Prischepa 2, Yury V. Nefedov 2,* , Vladimir A. Kontorovich 3 and Ilya Y. Vinokurov 4 1 The Faculty of Geology, Federal State Budget Educational Institution of Higher Education, Saint-Petersburg Mining University, 199106 Saint-Petersburg, Russia; [email protected] 2 Oil and Gas Geology Department, Federal State Budget Educational Institution of Higher Education, Saint-Petersburg Mining University, Saint-199106 Petersburg, Russia; [email protected] 3 Siberian Branch, Russian Academy of Science, The Trofimuk Institute of Petroleum Geology and Geophysics, 630090 Novosibirsk, Russia; [email protected] 4 Deep Geophysics Department, Russian Geological Research Institute, 199106 Saint-Petersburg, Russia; [email protected] * Correspondence: [email protected]; Tel.: +7-911-230-56-36 Abstract: The evolutionary-genetic method, whereby modern sedimentary basins are interpreted as end-products of a long geological evolution of a system of conjugate palaeo-basins, enables the assessment of the petroleum potential of the Western sector of the Russian Arctic. Modern basins in this region contain relics of palaeo-basins of a certain tectonotype formed in varying geodynamic regimes. Petroleum potential estimates of the Western Arctic vary broadly—from 34.7 to more than 100 billion tons of oil equivalent with the share of liquid hydrocarbons from 5.3 to 13.4 billion tons of oil equivalent. At each stage of the development of palaeo-basins, favourable geological, geochemical and thermobaric conditions have emerged and determined the processes of oil and gas formation, Citation: Egorov, A.S.; Prischepa, migration, accumulation, and subsequent redistribution between different complexes.
    [Show full text]
  • Late Cretaceous to Paleogene Exhumation in Central Europe – Localized Inversion Vs
    https://doi.org/10.5194/se-2020-183 Preprint. Discussion started: 11 November 2020 c Author(s) 2020. CC BY 4.0 License. Late Cretaceous to Paleogene exhumation in Central Europe – localized inversion vs. large-scale domal uplift Hilmar von Eynatten1, Jonas Kley2, István Dunkl1, Veit-Enno Hoffmann1, Annemarie Simon1 1University of Göttingen, Geoscience Center, Department of Sedimentology and Environmental Geology, 5 Goldschmidtstrasse 3, 37077 Göttingen, Germany 2University of Göttingen, Geoscience Center, Department of Structural Geology and Geodynamics, Goldschmidtstrasse 3, 37077 Göttingen, Germany Correspondence to: Hilmar von Eynatten ([email protected]) Abstract. Large parts of Central Europe have experienced exhumation in Late Cretaceous to Paleogene time. Previous 10 studies mainly focused on thrusted basement uplifts to unravel magnitude, processes and timing of exhumation. This study provides, for the first time, a comprehensive thermochronological dataset from mostly Permo-Triassic strata exposed adjacent to and between the basement uplifts in central Germany, comprising an area of at least some 250-300 km across. Results of apatite fission track and (U-Th)/He analyses on >100 new samples reveal that (i) km-scale exhumation affected the entire region, (ii) thrusting of basement blocks like the Harz Mountains and the Thuringian Forest focused in the Late 15 Cretaceous (about 90-70 Ma) while superimposed domal uplift of central Germany is slightly younger (about 75-55 Ma), and (iii) large parts of the domal uplift experienced removal of 3 to 4 km of Mesozoic strata. Using spatial extent, magnitude and timing as constraints suggests that thrusting and crustal thickening alone can account for no more than half of the domal uplift.
    [Show full text]
  • Tectonic Evolution of the Mesozoic South Anyui Suture Zone, GEOSPHERE; V
    Research Paper GEOSPHERE Tectonic evolution of the Mesozoic South Anyui suture zone, GEOSPHERE; v. 11, no. 5 eastern Russia: A critical component of paleogeographic doi:10.1130/GES01165.1 reconstructions of the Arctic region 18 figures; 5 tables; 2 supplemental files; 1 animation Jeffrey M. Amato1, Jaime Toro2, Vyacheslav V. Akinin3, Brian A. Hampton1, Alexander S. Salnikov4, and Marianna I. Tuchkova5 1Department of Geological Sciences, New Mexico State University, MSC 3AB, P.O. Box 30001, Las Cruces, New Mexico 88003, USA CORRESPONDENCE: [email protected] 2Department of Geology and Geography, West Virginia University, 330 Brooks Hall, P.O. Box 6300, Morgantown, West Virginia 26506, USA 3North-East Interdisciplinary Scientific Research Institute, Far East Branch, Russian Academy of Sciences, Magadan, Portovaya Street, 16, 685000, Russia CITATION: Amato, J.M., Toro, J., Akinin, V.V., Hamp- 4Siberian Research Institute of Geology, Geophysics, and Mineral Resources, 67 Krasny Prospekt, Novosibirsk, 630091, Russia ton, B.A., Salnikov, A.S., and Tuchkova, M.I., 2015, 5Geological Institute, Russian Academy of Sciences, Pyzhevskii per. 7, Moscow, 119017, Russia Tectonic evolution of the Mesozoic South Anyui su- ture zone, eastern Russia: A critical component of paleogeographic reconstructions of the Arctic region: ABSTRACT INTRODUCTION Geosphere, v. 11 no. 5, p. 1530–1564, doi: 10 .1130 /GES01165.1. The South Anyui suture zone consists of late Paleozoic–Jurassic ultra- The South Anyui suture zone (Fig. 1) is a remnant of a Mesozoic ocean Received 19 December 2014 mafic rocks and Jurassic–Cretaceous pre-, syn-, and postcollisional sedimen- basin that separated the Arctic Alaska–Chukotka microplate from Siberia Revision received 2 July 2015 tary rocks.
    [Show full text]
  • African Origins 200 Million Years of Calcium Carbonate Deposition
    The Florida We are all So Familiar With is a relatively new phenomenon, geologically speaking. This distinctive peninsula of land we live on, and the gently sloping, sandy shorelines we’re drawn to for recreation and renewal, have not always existed as they appear today. In fact, Florida was a very different-looking place not so long ago, and over the past 500 million years it has had quite a unique and surprising geological history. African Origins Believe it or not, the deep bedrock that underlies Florida was originally a part of Africa. Florida’s oldest Scott, Means) rocks formed about 500 million years ago on the “megacontinent” Gondwana. They were wedged between other masses of rock that would eventually separate—through the activity of plate tectonics—into (Kosche, Bryan,(Kosche, the modern continents of Africa and South America. About 250 million years ago, Gondwana (containing the geologic beginnings of Florida) collided with another megacontinent called Laurasia (which contained the rest of future North America). The result was the supercontinent Pangea. When Pangea eventually broke up, about 230 million years ago, that special wedge of African bedrock that would be Florida, rifted apart from its tectonic plate of origin, and remained sutured instead to what we’ve come to know as the continent of North America. 200 Million Years of Calcium Carbonate Deposition It is upon these very old, African-born igneous and metamorphic basement rocks that the sedimentary rocks of the Florida Platform would start to accumulate. Thick layers of carbonate rock—predominantly limestones and dolostones composed of the mineral calcium carbonate— built up over the next 200 million years to create Florida’s flat-topped, “carbonate platform” structure.
    [Show full text]