Techniques for Understanding Fold-And-Thrust Belt Kinematics and Thermal Evolution
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Linking Megathrust Earthquakes to Brittle Deformation in a Fossil Accretionary Complex
ARTICLE Received 9 Dec 2014 | Accepted 13 May 2015 | Published 24 Jun 2015 DOI: 10.1038/ncomms8504 OPEN Linking megathrust earthquakes to brittle deformation in a fossil accretionary complex Armin Dielforder1, Hauke Vollstaedt1,2, Torsten Vennemann3, Alfons Berger1 & Marco Herwegh1 Seismological data from recent subduction earthquakes suggest that megathrust earthquakes induce transient stress changes in the upper plate that shift accretionary wedges into an unstable state. These stress changes have, however, never been linked to geological structures preserved in fossil accretionary complexes. The importance of coseismically induced wedge failure has therefore remained largely elusive. Here we show that brittle faulting and vein formation in the palaeo-accretionary complex of the European Alps record stress changes generated by subduction-related earthquakes. Early veins formed at shallow levels by bedding-parallel shear during coseismic compression of the outer wedge. In contrast, subsequent vein formation occurred by normal faulting and extensional fracturing at deeper levels in response to coseismic extension of the inner wedge. Our study demonstrates how mineral veins can be used to reveal the dynamics of outer and inner wedges, which respond in opposite ways to megathrust earthquakes by compressional and extensional faulting, respectively. 1 Institute of Geological Sciences, University of Bern, Baltzerstrasse 1 þ 3, Bern CH-3012, Switzerland. 2 Center for Space and Habitability, University of Bern, Sidlerstrasse 5, Bern CH-3012, Switzerland. 3 Institute of Earth Surface Dynamics, University of Lausanne, Geˆopolis 4634, Lausanne CH-1015, Switzerland. Correspondence and requests for materials should be addressed to A.D. (email: [email protected]). NATURE COMMUNICATIONS | 6:7504 | DOI: 10.1038/ncomms8504 | www.nature.com/naturecommunications 1 & 2015 Macmillan Publishers Limited. -
GEO 2008 Conference Abstracts, Bahrain GEO 2008 Conference Abstracts
GEO 2008 conference abstracts, Bahrain GEO 2008 Conference Abstracts he abstracts of the GEO 2008 Conference presentations (3-5 March 2008, Bahrain) are published in Talphabetical order based on the last name of the first author. Only those abstracts that were accepted by the GEO 2008 Program Committee are published here, and were subsequently edited by GeoArabia Editors and proof-read by the corresponding author. Several names of companies and institutions to which presenters are affiliated have been abbreviated (see page 262). For convenience, all subsidiary companies are listed as the parent company. (#117804) Sandstone-body geometry, facies existing data sets and improve exploration decision architecture and depositional model of making. The results of a recent 3-D seismic reprocessing Ordovician Barik Sandstone, Oman effort over approximately 1,800 square km of data from the Mediterranean Sea has brought renewed interest in Iftikhar A. Abbasi (Sultan Qaboos University, Oman) deep, pre-Messinian structures. Historically, the reservoir and Abdulrahman Al-Harthy (Sultan Qaboos targets in the southern Mediterranean Sea have been the University, Oman <[email protected]>) Pliocene-Pleistocene and Messinian/Pre-Messinian gas sands. These are readily identifiable as anomalousbright The Lower Paleozoic siliciclastics sediments of the amplitudes on the seismic data. The key to enhancing the Haima Supergroup in the Al-Haushi-Huqf area of cen- deeper structure is multiple and noise attenuation. The tral Oman are subdivided into a number of formations Miocene and older targets are overlain by a Messinian- and members based on lithological characteristics of aged, structurally complex anhydrite layer, the Rosetta various rock sequences. -
Preliminary Catalog of the Sedimentary Basins of the United States
Preliminary Catalog of the Sedimentary Basins of the United States By James L. Coleman, Jr., and Steven M. Cahan Open-File Report 2012–1111 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Marcia K. McNutt, Director U.S. Geological Survey, Reston, Virginia: 2012 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1–888–ASK–USGS. For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod To order this and other USGS information products, visit http://store.usgs.gov Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. Suggested citation: Coleman, J.L., Jr., and Cahan, S.M., 2012, Preliminary catalog of the sedimentary basins of the United States: U.S. Geological Survey Open-File Report 2012–1111, 27 p. (plus 4 figures and 1 table available as separate files) Available online at http://pubs.usgs.gov/of/2012/1111/. iii Contents Abstract ...........................................................................................................................................................1 -
Kinematic Reconstruction of the Caribbean Region Since the Early Jurassic
Earth-Science Reviews 138 (2014) 102–136 Contents lists available at ScienceDirect Earth-Science Reviews journal homepage: www.elsevier.com/locate/earscirev Kinematic reconstruction of the Caribbean region since the Early Jurassic Lydian M. Boschman a,⁎, Douwe J.J. van Hinsbergen a, Trond H. Torsvik b,c,d, Wim Spakman a,b, James L. Pindell e,f a Department of Earth Sciences, Utrecht University, Budapestlaan 4, 3584 CD Utrecht, The Netherlands b Center for Earth Evolution and Dynamics (CEED), University of Oslo, Sem Sælands vei 24, NO-0316 Oslo, Norway c Center for Geodynamics, Geological Survey of Norway (NGU), Leiv Eirikssons vei 39, 7491 Trondheim, Norway d School of Geosciences, University of the Witwatersrand, WITS 2050 Johannesburg, South Africa e Tectonic Analysis Ltd., Chestnut House, Duncton, West Sussex, GU28 OLH, England, UK f School of Earth and Ocean Sciences, Cardiff University, Park Place, Cardiff CF10 3YE, UK article info abstract Article history: The Caribbean oceanic crust was formed west of the North and South American continents, probably from Late Received 4 December 2013 Jurassic through Early Cretaceous time. Its subsequent evolution has resulted from a complex tectonic history Accepted 9 August 2014 governed by the interplay of the North American, South American and (Paleo-)Pacific plates. During its entire Available online 23 August 2014 tectonic evolution, the Caribbean plate was largely surrounded by subduction and transform boundaries, and the oceanic crust has been overlain by the Caribbean Large Igneous Province (CLIP) since ~90 Ma. The consequent Keywords: absence of passive margins and measurable marine magnetic anomalies hampers a quantitative integration into GPlates Apparent Polar Wander Path the global circuit of plate motions. -
Lesson 3 Forces That Build the Land Main Idea
Lesson 3 Forces That Build the Land Main Idea Many landforms result from changes and movements in Earth’s crust. Objectives Identify types of landforms and the processes that form them. Describe what happens when an earthquake occurs. Vocabulary fault focus aftershock seismic wave epicenter seismograph magnitude vent What forces change Earth’s crust? At transform boundaries, the pieces of rock rub together in a force called shearing, like the blades of a pair of scissors, causing the rock to break. At convergent boundaries, plates collide and this force is called compression, squeezing the rock together. At divergent boundaries, plates separate causing tension, making the crust longer and thinner eventually breaking and creating a fault. Faults are usually located along the boundaries between tectonic plates. Three Kinds of Faults Shearing forms strike-slip faults. Tension forms normal faults. The rock above the fault moves down. Compression forms reverse faults. The rock above the fault moves up. Uplifted Landforms Folded mountains are mostly made up of rock layers folded by being squeezed together. Fault-block mountains are made by huge, tilted blocks of rock separated from the surrounding rock by faults. The Colorado Plateau was formed when rock layers were pushed upward. The Colorado River eventually formed the Grand Canyon. Quick Check Infer Why are faults often produced along plate boundaries? Forces act on the crust most directly at plate boundaries, because these locations are where plates are moving, relative to each other. Critical Thinking Why do some mountains form as folded mountains and others form as fault-block mountains? Compression forces form folded mountains, and tension forms fault- block mountains. -
The Terrane Concept and the Scandinavian Caledonides: a Synthesis
The terrane concept and the Scandinavian Caledonides: a synthesis DAVID ROBERTS Roberts , D. 1988: The terrane concept and the Scandinavian Caledonides: a synthesis. Nor. geol . unders . Bull. 413. 93-99. A revised terrane map is presented for the Scandinavian Caledcnldes. and an outline is given of the principal suspect and exot ic terranes and terrane-complexe s identified outboa rd from the Baltoscand ian miogeocline. The outermost part of the Baltoscandian continental margin is itself suspect , in the terrane sense. since the true palaeogeographical location s of rocks now represented in the Seve and serey-seuano Nappes, while inferred, are not known. The orogen -internal exotic terranes embrace the oceanic/eugeoclinal elements of the Caledonides, represented by the mag matosed imentary assemblages of the Koli Nappes, including ophiolite fragments and island arc products. Even more exot ic terranes occur in the highest parts of the tectonostratigraphy, inclu ding units which are thought possibly to derive from the Laurentian side of lapetus . D. Roberts. Norges geologiske uruierseketse, Postboks 3006. Lade, N-7002 Trondbeim , Norway . Introduction Project 233 has been to prepare a preliminary Earlier in this decade much of the research terrane map' at 1:5 M scale (Roberts et al. effort in the Caledonides of Scandinavia was 1986) for a larger, circum-Atlantic compilation. channelled through the highly successfu l IGCP This map, much simplified, is really one of Project 27 The Caledonide Orogen ' (Gee & palaeo-environments (marginal basins, vol Sturt 1985). An important aspect of the collabo canic arc comp lexes, overstep sequences , rative work in this project was that of map etc.), and not of terranes in the true sense. -
Part 3: Normal Faults and Extensional Tectonics
12.113 Structural Geology Part 3: Normal faults and extensional tectonics Fall 2005 Contents 1 Reading assignment 1 2 Growth strata 1 3 Models of extensional faults 2 3.1 Listric faults . 2 3.2 Planar, rotating fault arrays . 2 3.3 Stratigraphic signature of normal faults and extension . 2 3.4 Core complexes . 6 4 Slides 7 1 Reading assignment Read Chapter 5. 2 Growth strata Although not particular to normal faults, relative uplift and subsidence on either side of a surface breaking fault leads to predictable patterns of erosion and sedi mentation. Sediments will fill the available space created by slip on a fault. Not only do the characteristic patterns of stratal thickening or thinning tell you about the 1 Figure 1: Model for a simple, planar fault style of faulting, but by dating the sediments, you can tell the age of the fault (since sediments were deposited during faulting) as well as the slip rates on the fault. 3 Models of extensional faults The simplest model of a normal fault is a planar fault that does not change its dip with depth. Such a fault does not accommodate much extension. (Figure 1) 3.1 Listric faults A listric fault is a fault which shallows with depth. Compared to a simple planar model, such a fault accommodates a considerably greater amount of extension for the same amount of slip. Characteristics of listric faults are that, in order to maintain geometric compatibility, beds in the hanging wall have to rotate and dip towards the fault. Commonly, listric faults involve a number of en echelon faults that sole into a lowangle master detachment. -
Tectonics and Sedimentation in Foreland Basins: Results from the Integrated Basin Studies Project
Downloaded from http://sp.lyellcollection.org/ by guest on September 30, 2021 Tectonics and sedimentation in foreland basins: results from the Integrated Basin Studies project ALAIN MASCLE 1 & CAI PUIGDEFABREGAS 2,3 IIFP School, 228-232 avenue Napoldon Bonaparte, 92852 Rueil-Malmaison Cedex, France (e-mail: [email protected]) 2Norsk Hydro Research Centre, Bergen, Norway. 3Institut de Ciences de la Terra, (?SIC, Barcelona, Spain. Why foreland basins? to a better understanding of some basic interact- ing tectonic, sedimentary and hydrologic pro- Over the last ten years or so, since the Fribourg cesses (More & Vrolijk 1992; Touret & van meeting in 1985 (Homewood et al. 1986), the Hinte 1992). Additional data have also been attention given by sedimentologists and struc- obtained through the development of analogue tural geologists to the geology of foreland basins and numerical models (Larroque et al. 1992; has been growing continuously, parallel to the Zoetemeijer 1993). The physical parameters increase of co-operative links between scientists controlling the forward propagation of d6colle- from the two disciplines. A number of reasons ments and thrusts (fluid pressure, roughness, lie behind this development. Attempting to sediment thickness, etc.) have been determined understand the growth of an orogen without and tested. The relationships between rapidly paying due attention to the stratigraphic record subsiding piggyback basins and growing ramp of the derived sediments would be unrealistic. It anticlines have also been imaged, although the would, moreover, be equally unrealistic to con- lack of deep-sea well control still prevents accu- struct restored sections across the chain without rate sedimentological studies. More significant considering the constraints imposed by the has been the progress in our understanding of basin-fill architecture, or to describe the basin- the role of fluids and pore pressure in the fill evolution disregarding the development of development of thrust belts. -
Tectonics of the Musandam Peninsula and Northern Oman Mountains: from Ophiolite Obduction to Continental Collision
GeoArabia, 2014, v. 19, no. 2, p. 135-174 Gulf PetroLink, Bahrain Tectonics of the Musandam Peninsula and northern Oman Mountains: From ophiolite obduction to continental collision Michael P. Searle, Alan G. Cherry, Mohammed Y. Ali and David J.W. Cooper ABSTRACT The tectonics of the Musandam Peninsula in northern Oman shows a transition between the Late Cretaceous ophiolite emplacement related tectonics recorded along the Oman Mountains and Dibba Zone to the SE and the Late Cenozoic continent-continent collision tectonics along the Zagros Mountains in Iran to the northwest. Three stages in the continental collision process have been recognized. Stage one involves the emplacement of the Semail Ophiolite from NE to SW onto the Mid-Permian–Mesozoic passive continental margin of Arabia. The Semail Ophiolite shows a lower ocean ridge axis suite of gabbros, tonalites, trondhjemites and lavas (Geotimes V1 unit) dated by U-Pb zircon between 96.4–95.4 Ma overlain by a post-ridge suite including island-arc related volcanics including boninites formed between 95.4–94.7 Ma (Lasail, V2 unit). The ophiolite obduction process began at 96 Ma with subduction of Triassic–Jurassic oceanic crust to depths of > 40 km to form the amphibolite/granulite facies metamorphic sole along an ENE- dipping subduction zone. U-Pb ages of partial melts in the sole amphibolites (95.6– 94.5 Ma) overlap precisely in age with the ophiolite crustal sequence, implying that subduction was occurring at the same time as the ophiolite was forming. The ophiolite, together with the underlying Haybi and Hawasina thrust sheets, were thrust southwest on top of the Permian–Mesozoic shelf carbonate sequence during the Late Cenomanian–Campanian. -
THE JOURNAL of GEOLOGY March 1990
VOLUME 98 NUMBER 2 THE JOURNAL OF GEOLOGY March 1990 QUANTITATIVE FILLING MODEL FOR CONTINENTAL EXTENSIONAL BASINS WITH APPLICATIONS TO EARLY MESOZOIC RIFTS OF EASTERN NORTH AMERICA' ROY W. SCHLISCHE AND PAUL E. OLSEN Department of Geological Sciences and Lamont-Doherty Geological Observatory of Columbia University, Palisades, New York 10964 ABSTRACT In many half-graben, strata progressively onlap the hanging wall block of the basins, indicating that both the basins and their depositional surface areas were growing in size through time. Based on these con- straints, we have constructed a quantitative model for the stratigraphic evolution of extensional basins with the simplifying assumptions of constant volume input of sediments and water per unit time, as well as a uniform subsidence rate and a fixed outlet level. The model predicts (1) a transition from fluvial to lacustrine deposition, (2) systematically decreasing accumulation rates in lacustrine strata, and (3) a rapid increase in lake depth after the onset of lacustrine deposition, followed by a systematic decrease. When parameterized for the early Mesozoic basins of eastern North America, the model's predictions match trends observed in late Triassic-age rocks. Significant deviations from the model's predictions occur in Early Jurassic-age strata, in which markedly higher accumulation rates and greater lake depths point to an increased extension rate that led to increased asymmetry in these half-graben. The model makes it possible to extract from the sedimentary record those events in the history of an extensional basin that are due solely to the filling of a basin growing in size through time and those that are due to changes in tectonics, climate, or sediment and water budgets. -
Developing the Orogenic Gold Deposit Model: Insights from R&D for Exploration Success
"Accretionary Wedge Geodynamic Evolution, Metamorphic Equilibria, Metasomatic Processes, & GOLD” by Dave Lentz (UNB) Accretionary ophiolitic sequence (with quartz veins), basement Santorini, Greece 2m Orogenic Gold first used by Bohlke (1982) Developing the Orogenic Gold Deposit Model: Insights from R&D for Exploration Success by Dave Lentz (UNB) Accretionary ophiolitic sequence (with quartz veins), basement Santorini, Greece 2m Orogenic Gold first used by Bohlke (1982) SPONSORS INTRODUCTION PART I: Review Gold Deposit Settings • Historical Evolution of ideas • Description of Orogenic Au Systems • Enigmatic aspects of the metamorphogenic model PART II: Geothermal to Hydrothermal Evolution • Metamorphic Considerations to Thermal Evolution • Fluid Source (and Solubility Implications) PART III: Geodynamic Evolution • Accretionary Geodynamics (to collision) • Structural-Metamorphic Evolution & Settings • Implications for refining the metamorphogenic Orogenic Gold Model PART I: Review Gold Deposit Settings Mineralization in forearc to back arc system Accretionary Wedge fore arc settings Mitchell & Garson (1982) OROGENIC GOLD: Magmatic to Metamorphic hydrothermal continuum Groves et al. (1998) How are Gold Systems Related to Crustal Growth? From Goldfarb (2006) Magmatic-dominated Metamorphic-dominated Groves et al. (1998) Metamorphic,Metamorphic, Transitional,Transitional, andand MagmaticMagmatic GoldGold ModelsModels Poulsen (2000) Metamorphic dominated Setting Juneau Belt Prehnite- Donlin Creek pumpellite Ross Mine Kirkland Lake Dome Brittle Sigma/Giant-Con Greenschist Hollinger-McIntyre Ductile-Brittle Amphibolite Red Lake Eastmain/Lynn Lake Musselwhite Granulite Ductile Lake Lilois Fluid Egress along Advective Crustal-scale Heat n Shear Zone o i t Transfer a n o Z l a t e Zone of deposition M Low salinities (< 3 wt % NaCl, KCl, etc.) Source Region (or deeper) Fyfe & Henley (1973) RETROGRESSION PART II: Geothermal to Hydrothermal Evolution Fluid movement Ethridge et al. -
Geotectonic Model of the Alpine Development of Lakavica Graben in the Eastern Part of the Vardar Zone in the Republic of Macedonia
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by UGD Academic Repository Geologica Macedonica, Vol. 27, No. 1, pp. 87–93 (2013) GEOME 2 ISSN 0352 – 1206 Manuscript received: May 17, 2013 UDC: 551.245.03(497.71/.73) Accepted: October 25, 2013 Original scientific paper GEOTECTONIC MODEL OF THE ALPINE DEVELOPMENT OF LAKAVICA GRABEN IN THE EASTERN PART OF THE VARDAR ZONE IN THE REPUBLIC OF MACEDONIA Goše Petrov, Violeta Stojanova, Gorgi Dimov Faculty of Natural and Technical Sciences, “Goce Delčev” University, P.O.Box 201, MK 2000 Štip, Republic of Macedonia [email protected]//[email protected] A b s t r a c t: Lakavica graben is located in the eastern subzone of the Vardar zone, which during the Alpine orogenesis was covered with very complex processes of tectogenesis. On the area of about 200 km2, in the Lakavica graben, are present geological units from the oldest geological periods (Precam- brian) to the youngest (Neogene and Quaternary). Tectonic structure, or rupture tectonic, is very intense developed and gives possibility for analysis of the geotectonic processes in the Alpine orogen phase. This paper presents the possible model for geotectonic processes in the Lakavica graben, according to which can be generalized geotectonic processes in the Vardar zone during the Alpine orogeny. Key words: Lakavica graben; geotectonic model; Alpine orogeny; Vardar zone INTRODUCTION Vardar zone as a tectonic unit, for the first niki Gulf (Greece), than bent eastward and crosses time, is separated and showed on the "Geological- the ophiolite zone Izmir–Ankara (Turkey).