DOCSLIB.ORG

50. Structure and Evolution of the Mediterranean Basins

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
50. Structure and Evolution of the Mediterranean Basins 50. STRUCTURE AND EVOLUTION OF THE MEDITERRANEAN BASINS Bernard Biju-Duval, Jean Letouzey, and Lucien Montadert, Institut Français du Petrole Rueil-Malmaison, France ABSTRACT In this paper we attempt to reconstruct the general history of the Alpine-Mediterranean realm on the basis of geological cross- sections onland and offshore, general mapping of the basins and the main structural units of the Mediterranean area, and geophysi- cal data. The history of the Alpine-Mediterranean realm is related to the plate movements of Europe and Africa and associated with the opening of the Atlantic. After a first stage with a broad oceanic domain (Tethys), the opening of a proto-eastern Mediterranean and the formation of active margins south of Europe modified the physiography until the stage of continental collision. The western and eastern Mediterranean basins differ. The western basins are very young: Oligocene-Miocene episutural and intracontinental marginal basins, recently rejuvenated (Tyrrhenian Sea) and always part of the Alpine orogenic belt. The eastern basins are remnants of a former much larger Mesozoic basin south of the still active Alpine belt. The Cyprus, Aegean, and Calabrian arcs are described succes- sively. Diagrammatic sections and schematic maps show this Ceno- zoic evolution and a speculative history is presented. INTRODUCTION northern Algeria [Burollet et al., in press]; Israel [Gvirtzman et al., in press]; Turkey, the Aegean Sea, Relatively few seismic reflection data with good etc.). penetration were available in the deep Mediterranean All this information can be used to place the results basins at the time of the completion of DSDP Leg 13. of Leg 42A in a broad geological setting and we In particular, almost no information existed on the attempt here to emphasize the contribution of Leg 42A geological structure below the top of the Messinian to the reconstruction of the structural history of the evaporites defined by Horizon M (Ryan, 1969). The Mediterranean basins (Figure 1). first deep seismic information came with the use of Drilling and seismic reflection, however, give data multichannel seismic reflection which was used in 1970 mainly on the more recent geological history only: to establish the seismic stratigraphy of the deep west- primarily the Cenozoic in the western Mediterranean ern Mediterranean basins (Montadert et al., 1970). and part of the Mesozoic in the eastern Mediterranean. Since that time, data accumulated by several institu- But the recent history of these basins is related to their tions (IFP-CEPM, OGST, CNEXO, etc.) and oil com- earlier history and we must consider the geological panies have produced a better understanding of the events that succeeded one another in the region be- general geological framework of the different Mediter- tween Africa and Eurasia before describing the present ranean basins (Mulder, 1973; Finetti et al., 1973; basins. Mauffret et al., 1973; Biju-Duval et al., 1974; Morelli, Because of the very large number of publications 1975). concerning the Mediterranean area that have appeared These new data enabled new objectives to be pro- in the last 100 years, we cannot give a complete posed for the Glomar Challenger. In particular, the bibliography of all the papers considered in this syn- possibility of exploring the pre-evaporitic series was thesis. Many of them have been cited in previous recognized. These objectives were defined by several papers (Biju-Duval et al., 1974; Biju-Duval, 1974). site surveys conducted in both the Western and Eastern Consequently, we cite here only more recent papers or Mediterranean Sea by IFP-CNEXO with multichannel those useful for providing a general background or seismic reflection. specific data. Moreover, some information from offshore oil drill- ing has recently been published. These data are of prime importance for understanding the geological OUTLINE OF THE GEOLOGICAL HISTORY OF history of the margins and deep basins, and they THE ALPINE-MEDITERRANEAN AREA DURING provide an opportunity to relate land geological data MESOZOIC AND EARLY CENOZOIC TIME and DSDP drilling data (for example, drilling in the Several attempts have previously been made to Gulf of Lion [Cravatte et al., 1974] Gulf of Valencia, reconstruct the Alpine-Mediterranean geological his- 951 B. BIJU-DUVAL, J. LETOUZEY, L. MONTADERT 1 Sedimentary Basins 2 Stable Areas 3 Orogenic Belts 4 Main directions of folding 5 Major overthrusts , fronts of nappes 6 Major faults a) onshore b) offshore Figure 1. Structural map of the Mediterranean Sea. tory following different approaches: (1) from mainly employ the broad plate tectonic framework for the land data (for example, Klemme, 1958; Dercourt, Alpine-Mediterranean area which was briefly presented 1970; Argyriadis, 1975; Enay, 1972; etc.); (2) from the by Biju-Duval et al. (Split Symposium, 1976) and was application of plate tectonics concepts, using a reconsti- discussed in detail later (Biju-Duval et al. 1977). tution of relative movements of Europe and Africa and recognizing the geological consequences in the Alpine- Pre-Mesozoic (Figure 2[1]) Mediterranean area (Dewey et al, 1973); or (3) by a Many geologists and geophysicists agree that before combination of both approaches (Bosellini et al., 1973; the Mesozoic a very large Tethyan Ocean existed in the Trumpy, 1975; Laubscher and Bernouilli, in press). east which was connected with the Pacific Ocean. This In this paper we do not try to present a detailed concept of a very large ocean, however, cannot be reconstruction, but to schematically present our view accepted as definitive. Argyriadis (1975) cast doubt on of the structural history of the area at different periods: it by arguing that no marginal- or oceanic-type Per- pre-Mesozoic, Triassic, upper Liasic, Upper Jurassic, mian deposits have been found. Also, the concepts of Upper Cretaceous, upper Eocene. We use these specu- plate kinematics, on the basis of Atlantic magnetic lations as a starting point for the discussion of the anomalies, do not allow for a precise fit before anom- western Mediterranean Basin, whose history began in aly 32 (Santonian). Before that time a small difference the Oligocene, and as a general framework for the in the Atlantic fit would introduce very great differ- older eastern Mediterranean Basin. In this paper, we ences in reconstructions of the eastern part of the 952 STRUCTURE AND EVOLUTION OF THE MEDITERRANEAN BASINS gravity slidings 8 Volcanism 9 Major recent deltas 10 Mediterranean Ridge - Central Black Sea High 11 Tyrrhenian abyssal plain 12 Bathymetry Figure I. (Continued). future Mediterranean area. Thus, the existence of this Menderes) the metamorphic series have been so af- large Tethys is still speculative, and consequently its fected by later orogenies that their true nature, age, western extent is also questionable. and structural position are currently being studied. For Note that all the Paleozoic massifs surrounding the example, recently metamorphosed platform deposits of western Mediterranean (Iberian Meseta, Pelvoux, Mer- Mesozoic age have been discovered around the Men- cantour, Corsica, Sardinia, Kabylia, Menorca, etc.) deres (5 th Symposium on the Geology of Aegean were involved in the Hercynian Orogeny. The southern Regions, 1975). Thus the pre-Triassic Tethys was boundary of the Hercynian fold belt was probably located between the Hercynian fold belt to the north located near the present Saharan flexure (Figure 211]). and the Arabic-African-Anatolian-Apulian plate in the There are only a few indications of flexures, possibly South. To the West, the Mesozoic features are located related to margins of upper Carboniferous to Permian inside the Hercynian fold belt. age, in the northwestern Sahara region. The Permian Djeffara flexure is an intracratonic feature. In the eastern Mediterranean, it now appears that the Paleo- Triassic-Lias Period (Figure 2[2]) zoic in Taurus (Turkey) is a northern extension of the In the Triassic a clear contrast in depositional Arabic-African series. It was not involved in the environment existed between the west and the east. Hercynian Orogeny. In Yugoslavia, Greece, western During the entire time the western area was receiving Turkey (Serbo-Macedonian, Pelagonian, Cyclades, shallow-water marine deposits or continental deposits 953 B. BIJU-DUVAL, J. LETOUZEY, L. MONTADERT / / iI 1 PRETRIASIC > 200 M.A. (Size of the Tethys depending 4 LOWER CRETACEOUS 125 M.A. Opening of the Atlantic on the southern Atlantic fit) L a 2 LIASIC 180 M.A. Opening of Western Tethys 5 UPPER CRETACEOUS 70 M.A. initiation of Eastern Mediterranean Continental collision north of Arabia 3 UPPER JURASSIC 150 M.A. First obduction of ophioiitβs 6 EOCENE 45 M.A. Continental collision Figure 2. Tentative plate evolution in the Tethys-Alpine-Mediterranean area. 954 STRUCTURE AND EVOLUTION OF THE MEDITERRANEAN BASINS with well-characterized brackish intercalations ("Ger- Characterization of the continental margins created manic facies"). After the Werfenian episode when at that time is nevertheless still difficult because of the continental or brackish influences predominated, a succession of several tectonic phases. Studies in pro- marine transgression occurred which probably came gress by Bernoulli, Marcoux, Bourbon, Lemoine, and from the east (Tethys) and resulted in deposition of Blanchet are resolving this problem. carbonate platform sediments. More restricted condi- tions with large evaporitic deposits prevailed during Late Jurassic (Figure 2[3]) the upper Triassic (Keuper). In the eastern area, In the east, the Late Jurassic was a time of intense toward the edges of the Tethys, the presence of marine tectonic activity (Paleo-Dinarides, Dercourt, 1970; "Alpine facies" indicate the proximity of an open sea Aubouin et al., 1970), with obduction of the ophiolites during that time. On these edges (Lombardy, Di- which were later reworked into the flysch. It is still narides, Hellenides), platform carbonate facies merge uncertain whether they are chunks of a true ocean floor into deep water facies, particularly in the upper Trias- or of a marginal basin. sic deposits (Bernoulli et al., 1974; Bosellini et al., We do not know if the oceanic area that had 1973).
Load more

Recommended publications
  • Sediment Dynamics in the Gulf of Lions: the Impact of Extreme Events
    ARTICLE IN PRESS Continental Shelf Research 28 (2008) 1867–1876 Contents lists available at ScienceDirect Continental Shelf Research journal homepage: www.elsevier.com/locate/csr Introduction Sediment dynamics in the Gulf of Lions: The impact of extreme events 1. Introduction many small rivers along their western coasts. The Po and Rhoˆne, whose watersheds originate from the Alps, show a prevailing Investigating the fate of riverborne or resuspended sediment seasonal variability with a spring increase in discharge due to that is transported across continental margins is a fundamental snowmelt. However, extreme flood events associated with intense task in developing our understanding of the factors impacting precipitation also occur with sub-decadal recurrence intervals. benthic habitats and ecosystems, the dispersal and sequestration The small rivers on the western coasts are largely event of chemical elements (e.g., carbon, contaminants), and, in the long dominated. Flood sediment is primarily deposited on prodeltas term, the construction of sedimentary strata and evolution of with some redistribution along the shelf under the effect of a continental margin morphology. general cyclonic drift of the shelf circulation. Canyons at the Sediment transport on continental margins depends on a wide southwest (SW) terminus of the shelves intercept the transport variety of processes, including surface waves, bottom-boundary- pathways and control the part of the sediment that is transferred layer currents, and fluid stratification; and parameters such as directly to the deep basin. particle input rates, seabed characteristics, accumulation rates, The Adriatic Sea and the Gulf of Lions also differ in important and slope stability. Large sediment-transporting events lead to the respects, particularly in their morphology.
    [Show full text]
  • The Mediterranean Region—A Geological Primer
    160 Article by William Cavazza1 and Forese Carlo Wezel2 The Mediterranean region—a geological primer 1 Dept. of Earth and Geoenvironmental Sciences, Univ. of Bologna, Italy. [email protected] 2 Institute of Environmental Dynamics, University of Urbino, Italy. [email protected] The last twenty-five years of geological investigation of the Mediterranean region have disproved the traditional Introduction notion that the Alpine-Himalayan mountain ranges Many important ideas and influential geological models have been originated from the closure of a single, albeit complex, developed based on research undertaken in the Mediterranean oceanic domain—the Tethys. Instead, the present-day region. For example, the Alps are the most studied orogen in the geological configuration of the Mediterranean region is world, their structure has been elucidated in great detail for the most part and has served as an orogenic model applied to other collisional the result of the creation and ensuing consumption of orogens. Ophiolites and olistostromes were defined and studied for two major oceanic basins—the Paleotethys and the the first time in this region. The Mediterranean Sea has possibly the Neotethys—and of additional smaller oceanic basins highest density of DSDP/ODP sites in the world, and extensive within an overall regime of prolonged interaction research on its Messinian deposits and on their on-land counterparts has provided a spectacular example for the generation of widespread between the Eurasian and the African-Arabian plates. basinal evaporites. Other portions of this region are less well under- In greater detail, there is still some debate about exactly stood and are now the focus of much international attention.
    [Show full text]
  • Iberian Plate-Kinematics in Paleomagnetic and Mantle Reference Frames, Gondwana Research (2016), Doi: 10.1016/J.Gr.2016.03.006
    ÔØ ÅÒÙ×Ö ÔØ Cretaceous slab break-off in the Pyrenees: Iberian plate-kinematics in paleo- magnetic and mantle reference frames Reinoud L.M. Vissers, Douwe J.J. van Hinsbergen, Douwe G. van der Meer, Wim Spakman PII: S1342-937X(16)30053-3 DOI: doi: 10.1016/j.gr.2016.03.006 Reference: GR 1599 To appear in: Gondwana Research Received date: 21 September 2015 Revised date: 2 March 2016 Accepted date: 3 March 2016 Please cite this article as: Vissers, Reinoud L.M., van Hinsbergen, Douwe J.J., van der Meer, Douwe G., Spakman, Wim, Cretaceous slab break-off in the Pyrenees: Iberian plate-kinematics in paleomagnetic and mantle reference frames, Gondwana Research (2016), doi: 10.1016/j.gr.2016.03.006 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ACCEPTED MANUSCRIPT Cretaceous slab break-off in the Pyrenees: Iberian plate- kinematics in paleomagnetic and mantle reference frames Reinoud L.M. Vissers1, Douwe J.J. van Hinsbergen1, Douwe G. van der Meer1,2, Wim Spakman1,3 1 Department of Earth Sciences, Utrecht University, Budapestlaan 4, Utrecht 3584 CD, Netherlands 2 Nexen Petroleum UK Ltd, 97 Oxford Road, Uxbridge, Middlesex UB8 1LU, UK 3 Center for Earth Evolution and Dynamics (CEED), University of Oslo, Sem Saelands vei 24, NO-0316 Oslo, Norway corresponding author: Reinoud L.M.
    [Show full text]
  • Shellfish Reefs at Risk
    SHELLFISH REEFS AT RISK A Global Analysis of Problems and Solutions Michael W. Beck, Robert D. Brumbaugh, Laura Airoldi, Alvar Carranza, Loren D. Coen, Christine Crawford, Omar Defeo, Graham J. Edgar, Boze Hancock, Matthew Kay, Hunter Lenihan, Mark W. Luckenbach, Caitlyn L. Toropova, Guofan Zhang CONTENTS Acknowledgments ........................................................................................................................ 1 Executive Summary .................................................................................................................... 2 Introduction .................................................................................................................................. 6 Methods .................................................................................................................................... 10 Results ........................................................................................................................................ 14 Condition of Oyster Reefs Globally Across Bays and Ecoregions ............ 14 Regional Summaries of the Condition of Shellfish Reefs ............................ 15 Overview of Threats and Causes of Decline ................................................................ 28 Recommendations for Conservation, Restoration and Management ................ 30 Conclusions ............................................................................................................................ 36 References .............................................................................................................................
    [Show full text]
  • Marine Mammals and Sea Turtles of the Mediterranean and Black Seas
    Marine mammals and sea turtles of the Mediterranean and Black Seas MEDITERRANEAN AND BLACK SEA BASINS Main seas, straits and gulfs in the Mediterranean and Black Sea basins, together with locations mentioned in the text for the distribution of marine mammals and sea turtles Ukraine Russia SEA OF AZOV Kerch Strait Crimea Romania Georgia Slovenia France Croatia BLACK SEA Bosnia & Herzegovina Bulgaria Monaco Bosphorus LIGURIAN SEA Montenegro Strait Pelagos Sanctuary Gulf of Italy Lion ADRIATIC SEA Albania Corsica Drini Bay Spain Dardanelles Strait Greece BALEARIC SEA Turkey Sardinia Algerian- TYRRHENIAN SEA AEGEAN SEA Balearic Islands Provençal IONIAN SEA Syria Basin Strait of Sicily Cyprus Strait of Sicily Gibraltar ALBORAN SEA Hellenic Trench Lebanon Tunisia Malta LEVANTINE SEA Israel Algeria West Morocco Bank Tunisian Plateau/Gulf of SirteMEDITERRANEAN SEA Gaza Strip Jordan Suez Canal Egypt Gulf of Sirte Libya RED SEA Marine mammals and sea turtles of the Mediterranean and Black Seas Compiled by María del Mar Otero and Michela Conigliaro The designation of geographical entities in this book, and the presentation of the material, do not imply the expression of any opinion whatsoever on the part of IUCN concerning the legal status of any country, territory, or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. The views expressed in this publication do not necessarily reflect those of IUCN. Published by Compiled by María del Mar Otero IUCN Centre for Mediterranean Cooperation, Spain © IUCN, Gland, Switzerland, and Malaga, Spain Michela Conigliaro IUCN Centre for Mediterranean Cooperation, Spain Copyright © 2012 International Union for Conservation of Nature and Natural Resources With the support of Catherine Numa IUCN Centre for Mediterranean Cooperation, Spain Annabelle Cuttelod IUCN Species Programme, United Kingdom Reproduction of this publication for educational or other non-commercial purposes is authorized without prior written permission from the copyright holder provided the sources are fully acknowledged.
    [Show full text]
  • Readingsample
    The TRANSMED Atlas. The Mediterranean Region from Crust to Mantle Geological and Geophysical Framework of the Mediterranean and the Surrounding Areas Bearbeitet von William Cavazza, François M. Roure, Wim Spakman, Gerard M. Stampfli, Peter A. Ziegler 1. Auflage 2004. Buch. xxiii, 141 S. ISBN 978 3 540 22181 4 Format (B x L): 19,3 x 27 cm Gewicht: 660 g Weitere Fachgebiete > Physik, Astronomie > Angewandte Physik > Geophysik Zu Inhaltsverzeichnis schnell und portofrei erhältlich bei Die Online-Fachbuchhandlung beck-shop.de ist spezialisiert auf Fachbücher, insbesondere Recht, Steuern und Wirtschaft. Im Sortiment finden Sie alle Medien (Bücher, Zeitschriften, CDs, eBooks, etc.) aller Verlage. Ergänzt wird das Programm durch Services wie Neuerscheinungsdienst oder Zusammenstellungen von Büchern zu Sonderpreisen. Der Shop führt mehr als 8 Millionen Produkte. Chapter 1 The Mediterranean Area and the Surrounding Regions: Active Processes, Remnants of Former Tethyan Oceans and Related Thrust Belts William Cavazza · François Roure · Peter A. Ziegler Abstract 1.1 Introduction The Mediterranean domain provides a present-day geo- From the pioneering studies of Marsili – who singlehand- dynamic analog for the final stages of a continent-conti- edly founded the field of oceanography with the publi- nent collisional orogeny. Over this area, oceanic lithos- cation in 1725 of the Histoire physique de la mer, a scien- pheric domains originally present between the Eurasian tific best-seller of the time (Sartori 2003) – to the tech- and African-Arabian plates have been subducted and par- nologically most advanced cruises of the R/V JOIDES tially obducted, except for the Ionian basin and the south- Resolution, the Mediterranean Sea has represented a cru- eastern Mediterranean.
    [Show full text]
  • 1. the Western Iberia Margin: a Geophysical and Geological Overview1
    Whitmarsh, R.B., Sawyer, D.S., Klaus, A., and Masson, D.G. (Eds.), 1996 Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 149 1. THE WESTERN IBERIA MARGIN: A GEOPHYSICAL AND GEOLOGICAL OVERVIEW1 L.M. Pinheiro,2 R.C.L. Wilson,3 R. Pena dos Reis,4 R.B. Whitmarsh,5 A. Ribeiro6 ABSTRACT This paper presents a general overview of the geology and geophysics of western Iberia, and in particular of the western Portuguese Margin. The links between the onshore and offshore geology and geophysics are especially emphasized. The west Iberia Margin is an example of a nonvolcanic rifted margin. The Variscan basement exposed on land in Iberia exhibits strike- slip faults and other structural trends, which had an important effect on the development, in time and space, of subsequent rift- ing of the continental margin and even perhaps influences the present-day offshore seismicity. The margin has had a long tec- tonic and magmatic history from the Late Triassic until the present day. Rifting first began in the Late Triassic; after about 70 Ma, continental separation began in the Tagus Abyssal Plain. Continental breakup then appears to have progressively migrated northwards, eventually reaching the Galicia Bank segment of the margin about 112 Ma. Although there is onshore evidence of magmatism throughout the period from the Late Triassic until 130 Ma and even later, this was sporadic and of insignificant vol- ume. Important onshore rift basins were formed during this period. Offshore, the record is complex and fragmentary. An ocean/ continent transition, over 150 km wide, lies beyond the shelf edge and is marked on its western side by a peridotite ridge and thin oceanic crust characterized by seafloor spreading anomalies.
    [Show full text]
  • Marine Plankton Diatoms of the West Coast of North America
    MARINE PLANKTON DIATOMS OF THE WEST COAST OF NORTH AMERICA BY EASTER E. CUPP UNIVERSITY OF CALIFORNIA PRESS BERKELEY AND LOS ANGELES 1943 BULLETIN OF THE SCRIPPS INSTITUTION OF OCEANOGRAPHY OF THE UNIVERSITY OF CALIFORNIA LA JOLLA, CALIFORNIA EDITORS: H. U. SVERDRUP, R. H. FLEMING, L. H. MILLER, C. E. ZoBELL Volume 5, No.1, pp. 1-238, plates 1-5, 168 text figures Submitted by editors December 26,1940 Issued March 13, 1943 Price, $2.50 UNIVERSITY OF CALIFORNIA PRESS BERKELEY, CALIFORNIA _____________ CAMBRIDGE UNIVERSITY PRESS LONDON, ENGLAND [CONTRIBUTION FROM THE SCRIPPS INSTITUTION OF OCEANOGRAPHY, NEW SERIES, No. 190] PRINTED IN THE UNITED STATES OF AMERICA Taxonomy and taxonomic names change over time. The names and taxonomic scheme used in this work have not been updated from the original date of publication. The published literature on marine diatoms should be consulted to ensure the use of current and correct taxonomic names of diatoms. CONTENTS PAGE Introduction 1 General Discussion 2 Characteristics of Diatoms and Their Relationship to Other Classes of Algae 2 Structure of Diatoms 3 Frustule 3 Protoplast 13 Biology of Diatoms 16 Reproduction 16 Colony Formation and the Secretion of Mucus 20 Movement of Diatoms 20 Adaptations for Flotation 22 Occurrence and Distribution of Diatoms in the Ocean 22 Associations of Diatoms with Other Organisms 24 Physiology of Diatoms 26 Nutrition 26 Environmental Factors Limiting Phytoplankton Production and Populations 27 Importance of Diatoms as a Source of food in the Sea 29 Collection and Preparation of Diatoms for Examination 29 Preparation for Examination 30 Methods of Illustration 33 Classification 33 Key 34 Centricae 39 Pennatae 172 Literature Cited 209 Plates 223 Index to Genera and Species 235 MARINE PLANKTON DIATOMS OF THE WEST COAST OF NORTH AMERICA BY EASTER E.
    [Show full text]
  • Barotropic Eastward Currents in the Western Gulf of Lion, North-Western Mediterranean Sea, During Stratified Conditions Andrei Petrenko, C
    Barotropic eastward currents in the western Gulf of Lion, north-western Mediterranean Sea, during stratified conditions Andrei Petrenko, C. Dufau, C. Estournel To cite this version: Andrei Petrenko, C. Dufau, C. Estournel. Barotropic eastward currents in the western Gulf of Lion, north-western Mediterranean Sea, during stratified conditions. Journal of Marine Systems, Elsevier, 2008, 74 (1-2), pp.406-428. 10.1016/j.jmarsys.2008.03.004. hal-00518970 HAL Id: hal-00518970 https://hal.archives-ouvertes.fr/hal-00518970 Submitted on 2 Mar 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License Barotropic eastward currents in the western Gulf of Lion, north-western Mediterranean Sea, during stratified conditions A. Petrenko a,⁎, C. Dufau b,1, C. Estournel b a Aix-Marseille Université, CNRS, LOB-UMR 6535, Laboratoire d'Océanographie Physique et de Biogéochimie, OSU/Centre d'Océanologie de Marseille, Marseille, Francev b Pôle d'Océanographie Côtière, Laboratoire d'Aérologie, Laboratoire d'Etudes en Géophysique et Océanographie Spatiales, Toulouse, France The circulation of the Gulf of Lion, a large continental shelf north of the western basin of the Mediterranean Sea, is complex and highly variable.
    [Show full text]
  • A Template for an Improved Rock-Based Subdivision of the Pre-Cryogenian Timescale
    Downloaded from http://jgs.lyellcollection.org/ by guest on September 28, 2021 Perspective Journal of the Geological Society Published Online First https://doi.org/10.1144/jgs2020-222 A template for an improved rock-based subdivision of the pre-Cryogenian timescale Graham A. Shields1*, Robin A. Strachan2, Susannah M. Porter3, Galen P. Halverson4, Francis A. Macdonald3, Kenneth A. Plumb5, Carlos J. de Alvarenga6, Dhiraj M. Banerjee7, Andrey Bekker8, Wouter Bleeker9, Alexander Brasier10, Partha P. Chakraborty7, Alan S. Collins11, Kent Condie12, Kaushik Das13, David A. D. Evans14, Richard Ernst15,16, Anthony E. Fallick17, Hartwig Frimmel18, Reinhardt Fuck6, Paul F. Hoffman19,20, Balz S. Kamber21, Anton B. Kuznetsov22, Ross N. Mitchell23, Daniel G. Poiré24, Simon W. Poulton25, Robert Riding26, Mukund Sharma27, Craig Storey2, Eva Stueeken28, Rosalie Tostevin29, Elizabeth Turner30, Shuhai Xiao31, Shuanhong Zhang32, Ying Zhou1 and Maoyan Zhu33 1 Department of Earth Sciences, University College London, London, UK 2 School of the Environment, Geography and Geosciences, University of Portsmouth, Portsmouth, UK 3 Department of Earth Science, University of California at Santa Barbara, Santa Barbara, CA, USA 4 Department of Earth and Planetary Sciences, McGill University, Montreal, Canada 5 Geoscience Australia (retired), Canberra, Australia 6 Instituto de Geociências, Universidade de Brasília, Brasilia, Brazil 7 Department of Geology, University of Delhi, Delhi, India 8 Department of Earth and Planetary Sciences, University of California, Riverside,
    [Show full text]
  • Structures, Deformation Mechanisms and Tectonic Phases, Recorded In
    European Scientific Journal Jume 2019 edition Vol.15, No.18 ISSN: 1857 – 7881 (Print) e - ISSN 1857- 7431 Structures, Deformation Mechanisms and Tectonic Phases, Recorded in Paleoproterozoic Granitoids of West African Craton, Southern Part: Example of Kan’s Complex (Central of Côte d’Ivoire) K. K. Jean Marie Pria, Laboratoire de Géologie du Socle et de Métallogénie, UFR-STRM, Université Félix Houphouët-Boigny de Cocody, Abidjan, Côte d’Ivoire Laboratoire des Géosciences et Environnement, Département de Géologie, Université Ibn Tofaïl de Kénitra, Maroc Yacouba Coulibaly, N. N’guessan Houssou, M. Ephrem Allialy, T. K. L. Dimitri Boya, Laboratoire de Géologie du Socle et de Métallogénie, UFR-STRM, Université Félix Houphouët-Boigny de Cocody, Abidjan, Côte d’Ivoire Mohamed Tayebi, Lamia Erraoui, Souad M’Rabet, Laboratoire des Géosciences et Environnement, Département de Géologie, Université Ibn Tofaïl de Kénitra, Maroc Doi: 10.19044/esj.2019.v15n18p315 URL:http://dx.doi.org/10.19044/esj.2019.v15n18p315 Abstract The granito-gneissic complex of Kan is located in the central part of the Paleoproterozoic domain of Côte d’Ivoire. It consists essentially of migmatitic and mylonitic gneisses with basic intrusions and xenoliths. This Proterozoic domain belongs to the Man Leo shield, southern part of West African craton (WAC). The present study, essentially based on a structural analysis at outcrop scale, aims to identify deformation mechanisms and tectonic phases recorded in the granito-gneissic complex of Kan. Deformation mechanisms include: (1) flattening, (2) constriction, (3) simple shear (4), rotation (5), brittle shear, and (6) extension. The Kan complex deformation occurred during four major tectonic phases named D1, D2, D3 and D4.
    [Show full text]
  • Classic Localities Explained: the Eastern French Pyrenees – from Mountain Belt to Foreland Basin
    The eastern French Pyrenees: from mountain belt to foreland basin Item Type Article Authors Satterfield, Dorothy; Rollinson, Hugh; Suthren, Roger Citation Satterfield, D., Rollinson, H., and Suthren, R. (2019). 'The eastern French Pyrenees: from mountain belt to foreland basin'. Geology Today: Localities explained 23, pp. 1-34. DOI 10.1111/gto.12291 Publisher Wiley Journal Geology Today Download date 28/09/2021 21:45:49 Item License http://onlinelibrary.wiley.com/termsAndConditions#vor Link to Item http://hdl.handle.net/10545/624573 Satterfield et al. – Classic Localities – French Pyrenees Classic localities explained: The Eastern French Pyrenees – from Mountain Belt to Foreland Basin Dorothy Satterfield, Hugh Rollinson and Roger Suthren Environmental Science, University of Derby, Kedleston Road, Derby, UK. DE22 1GB [email protected] Abstract The Pyrenees are a young mountain belt formed as part of the larger Alpine collision zone. This excursion explores the development of the Pyrenean Mountain Belt in southern France, from its early extensional phase in the mid-Cretaceous and subsequent collisional phase, through its uplift and erosion in the Late Cretaceous and again in the Eocene, which led to the development of the Aquitaine-Languedoc foreland basin. One of the complexities of the Pyrenean Belt is that thrusting, uplift and erosion during the Pyrenean orogeny exposed older Variscan basement rocks in the central core of the mountains, rocks which were metamorphosed during an earlier event in the late Carboniferous. Thus, this orogenic belt also tells the story of an earlier collision between Laurussia in the north and Gondwana in the south at ca 300 Ma, prior to the onset of the Pyrenean events at ca.
    [Show full text]