Download or read book Strain Localization and Exhumation of the Lower Crust written by Alice C. Newman and published by . This book was released on 2014 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, I present structural and kinematic data on rock fabrics, shear zones and fault zones from the Cretaceous Malaspina orthogneiss and some of its satellite plutons in central Fiordland, New Zealand. Central Fiordland exposes a large tract of granulite- to eclogite-facies lower crust that was exhumed between late Mesozoic to Cenozoic times. The deformational structures of interest were formed and preserved during the lifecycle of a Cretaceous continental arc that involved thickening to over 60 km followed by collapse and rifting. As such, they provide an excellent opportunity to study strain localization in the deep crust and the process of exhumation. Detailed structural mapping, analysis, and the construction of a 45-kilometer cross section through the Malaspina orthogneiss and adjacent plutons reveal the spatial distribution, sequence, and kinematics of crosscutting deformational structures. The earliest structures record Cretaceous magmatism, high-grade metamorphism at the granulite and eclogite facies, and ductile flow that resulted in widespread (over 1200 km2), disorganized magmatic foliations. These events were followed by regional extension that resulted in the formation of multiple, ≤0.5 km-thick ductile, upper amphibolite facies shear zones that record cooling, hydration, and horizontal flow during the Late Cretaceous. Extension continued but changed obliquity in the early to middle Tertiary and resulted in sets of strike-slip and normal brittle to semi-brittle faults forming a sinistral transtensional system. These faults are distributed across central Fiordland and crosscut and transpose the ductile shear zones and magmatic foliations. Lastly, a change in relative plate motions resulted in the inception of the Alpine fault and the development of a late Tertiary transpressional fault system that crosscuts all previous structures. The dominant factors controlling strain localization in central Fiordland changed from magma, heat, and melting, to fluid activity, plate boundary reorganization, and reactivation of inherited structures. The succession of contrasting strain localization styles in response to changing tectonic and local conditions led to the development of multiple phases of deformation. These multiple phases of deformation allowed the deep crust to be exhumed in a heterogeneous and fragmented, or 'piecemeal', way. In particular, the inability of late Cretaceous ductile shear zones to fully exhume the lower crust was compensated by the ability of early Tertiary transtensional faults to simultaneously thin and further exhume the lower crust. Investigations of strain localization patterns in central Fiordland shed light on the causes and mechanisms of crustal exhumation, a phenomenon that is integral to the lifecycle of virtually all orogenic belts.
Download or read book The Interplay Between Deformation and Metamorphism During Strain Localization in the Lower Crust Insights from Fiordland New Zealand written by Kathryn Elise Dianiska and published by . This book was released on 2015 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, I present field, microstructural, and Electron Backscatter Diffraction (EBSD) analyses of rock fabrics from high strain zones in exposures of lower crustal Cretaceous plutons at Breaksea Entrance, Fiordland, New Zealand. The interplay between deformation and metamorphism occurs across multiple scales at the root of a continental arc. I show a series of steps in which retrogressive metamorphism is linked to the accommodation of deformation. I define three main phases of deformation and metamorphism at Breaksea Entrance. The first phase (D1) involved emplacement of dioritic to gabbroic plutons at depths up to 60 km. The second phase (D2) is characterized by deformation and metamorphism at the granulite and eclogite facies that produced high strain zones with linear fabrics, isoclinal folding of igneous layering, and asymmetric pressure shadows around mafic aggregates. New structural analyses from Hāwea Island in Breaksea Entrance reveal the development of doubly plunging folds that define subdomes within larger, kilometer-scale gneiss domes. The development and intensification of S2 foliations within the domes was facilitated by the recrystallization of plagioclase and clinopyroxene at the micro-scale (subgrain rotation and grain boundary migration recrystallization), consistent with metamorphism at the granulite and eclogite facies and climb-accommodated dislocation creep. EBSD data show a strong crystallographic preferred orientation in plagioclase during D2 deformation. The third phase (D3) is characterized by deformation and metamorphism at the upper amphibolite facies that produced sets of discrete, narrow shear zones that wrap and encase lozenges of older fabrics. Structural analyses reveal a truncation and/or transposition relationship between the older S2 and the younger S3 foliations developed during D3. Progressive localization of deformation during cooling, hydration, and retrogression, resulted in the breakdown of garnet and pyroxene to form hornblende, biotite, fine plagioclase and quartz. EBSD data show a strong crystallographic preferred orientation in hornblende. During D3, hornblende and biotite accommodated most of the strain through fluid-assisted diffusion creep. The last two events (D2 and D3) reflect a transition in deformation and metamorphism during exhumation, as well as a focusing of strain and evolving strain localization mechanisms at the root of a continental arc. An examination of structures at multiple scales of observation reveals that fabrics seen in the field are a composite of multiple generations of deformation and metamorphism.
Download or read book Deformation Mechanisms and Strain Localization in the Mafic Continental Lower Crust written by Giulia Degli Alessandrini and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Non volcanic Rifting of Continental Margins written by Geological Society of London and published by Geological Society of London. This book was released on 2001 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: Non-continental margins lack thick lavas that are generated as continental crust thins immediately prior to the onset of seafloor spreading. They may form up to 30 per cent of passive margins around the world. This volume contains papers examining an active margin, fossil margins that border present day oceans, and remnants of margins exposed today in the Alps. The papers present evidence across a range of scales, from individual mineral grains, through borelide cores and outcrop, to whole margins at the crustal scale.
Download or read book Exhumation Associated with Continental Strike slip Fault Systems written by Alison B. Till and published by Geological Society of America. This book was released on 2007-01-01 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Channel Flow Ductile Extrusion and Exhumation in Continental Collision Zones written by Richard D. Law and published by Geological Society of London. This book was released on 2006 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume includes sections on: Evolution of ideas on channel flow and ductile extrusion in the Himalaya-Tibetan Plateau system; Modeling channel flow and ductile extrusion processes; Geological constraints on channel flow and ductile extrusion as an important orogenic process in the Himalaya-Tibetan Plateau, the Hellenides and Appalachians, and the Canadian Cordillera.
Download or read book Global Tectonics written by Philip Kearey and published by John Wiley & Sons. This book was released on 2013-05-28 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: The third edition of this widely acclaimed textbook provides acomprehensive introduction to all aspects of global tectonics, andincludes major revisions to reflect the most significant recentadvances in the field. A fully revised third edition of this highly acclaimed textwritten by eminent authors including one of the pioneers of platetectonic theory Major revisions to this new edition reflect the mostsignificant recent advances in the field, including new andexpanded chapters on Precambrian tectonics and the supercontinentcycle and the implications of plate tectonics for environmentalchange Combines a historical approach with process science to providea careful balance between geological and geophysical material inboth continental and oceanic regimes Dedicated website available at ahref="http://www.blackwellpublishing.com/kearey/"www.blackwellpublishing.com/kearey//a
Download or read book Dynamics of Plate Tectonics and Mantle Convection written by Joao Duarte and published by Elsevier. This book was released on 2023-02-10 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamics of Plate Tectonics and Mantle Convection, written by specialists in the field, gathers state-of-the-art perspectives on the dynamics of plate tectonics and mantle convection. Plate tectonics is a unifying theory of solid Earth sciences. In its initial form, it was a kinematic theory that described how the planet’s surface is fragmented into several rigid lithospheric plates that move in relation to each other over the less viscous asthenosphere. Plate tectonics soon evolved to describe the forces that drive and resist plate movements. The Earth sciences community is now developing a new perspective that looks at plate tectonics and mantle convection as part of a single system. Why does our planet have plate tectonics, and how does it work? How does mantle convection drive the supercontinent cycle? How have tectono-convective modes evolved over the Earth’s history? How did they shape the planet and impact life? Do other planets have mantle convection and tectonics? These are some of the fascinating questions explored in this book. This book started with a challenge from the editor to the authors to provide perspectives from their vantage point and open the curtain to the endeavors and stories behind the science. Provides diverse perspectives from different experts around the world in plate tectonics and geodynamics Includes the most up-to-date knowledge on plate tectonics and mantle convection Sets the scene for the developments and challenges likely to be faced by researchers in the future of geodynamics
Download or read book Issues in Biophysics and Geophysics Research and Application 2013 Edition written by and published by ScholarlyEditions. This book was released on 2013-05-01 with total page 1160 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Biophysics and Geophysics Research and Application: 2013 Edition is a ScholarlyEditions™ book that delivers timely, authoritative, and comprehensive information about Geophysics. The editors have built Issues in Biophysics and Geophysics Research and Application: 2013 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Geophysics in this book to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Biophysics and Geophysics Research and Application: 2013 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
Download or read book Deformation Mechanisms Rheology and Tectonics written by Siese de Meer and published by Geological Society of London. This book was released on 2002 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: The motion and deformation of rocks are processes of fundamental importance in shaping the Earth, from outer crustal layers to the deep mantle. Reconstructions of the evolution of the Earth therefore require detailed knowledge of the geometry of deformation structures and their relative timing, of the motions leading to deformation structures and of the mechanisms governing these motions. This volume contains a collection of 22 papers on field, experimental and theoretical studies that add to our knowledge of these processes.
Download or read book Tectonic DevelThermal History and Hydrocarbon Habitat Models of Transform Margins their Differences from Rifted Margins written by M. Nemčok and published by Geological Society of London Special Publications. This book was released on 2023-07-21 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transform margins form a significant portion of Earth’s continent–ocean transition and are integral to continental break-up, yet compared to other margins are poorly understood. This volume brings together new multidisciplinary research to document the structural, sedimentological and thermal evolution of transform margins, highlighting their relationship to continental structure, neighbouring oceanic segments, pull-apart basins and marginal plateaus. Special emphasis is given to the comparison of transform and rifted margins, and to the economic implications of transform margin structure and evolution. Transform case studies include the Agulhas–Falkland transform, Coromandal transform (East India), Davie margin and Limpopo transform (East Africa), Guyana transform margin, Demerara transform margin (Suriname), Romanche and St Paul transforms (equatorial Africa), Sagaing transform (Andaman Sea) and Zenith–Wallaby–Perth transform (West Australia). The broad-scale interplay between transform and rifted margin segments in the North and Central Atlantic, and Caribbean, is also examined.
Download or read book Orogenic Processes written by Wolfgang Franke (géologue).) and published by Geological Society of London. This book was released on 2000 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conjugate Divergent Margins written by Webster Mohriak and published by Geological Society of London. This book was released on 2013 with total page 569 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main focus of the book is the geological and geophysical interpretation of sedimentary basins along the South, Central and North Atlantic conjugate margins, but concepts derived from physical models, outcrop analogues and present-day margins are also discussed in some chapters. There is an encompassing description of several conjugate margins worldwide, based on recent geophysical and geological datasets. An overview of important aspects related to the geodynamic development and petroleum geology of Atlantic-type sedimentary basins is also included. Several chapters analyse genetic mechanisms and break-up processes associated with rift-phase structures and salt tectonics, providing a full description of conjugate margin basins based on deep seismic profiles and potential field methods.--
Download or read book Exposed Cross Sections of the Continental Crust written by M.H. Salisbury and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the Fall of 1988, 64 geologists and geophysicists from 11 countries met in Killarney, Ontario, on the north shore of Lake Huron to examine evidence that suggests that the continental crust is exposed in cross-section at several key locations on the Earth's surface. The meeting, which was held under NATO auspices as an Advanced Study Institute, was a landmark event in that it was the first time that many of the lead scientists working on these complexes in relative isolation around the world had' ever gathered together to compare results. The present volume is a compendium of the invited lectures given on the principle sections, plus an array of supporting papers on these and other sections as well as on related topics such as crustal emplacement mechanisms, deformation and rheology. Nearly all of the best known sections are represented, including the Ivrea Zone, Calabria, the Kapuskasing Zone, Fiordland and many others. It is our hope that this Volume will serve as a reference for Earth scientists who are trying to understand levels of the crust not normally exposed to view, as well as a point of departure for new research and a teaching aid to new entrants in this relatively new field of study.
Download or read book Geological Setting Palaeoenvironment and Archaeology of the Red Sea written by Najeeb M.A. Rasul and published by Springer. This book was released on 2018-12-05 with total page 788 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers invited contributions from active researchers to provide an up-to-date overview of the geological setting of the Red Sea. It discusses aspects ranging from historical information to modern research in the Red Sea, and presents findings from rapidly advancing, emerging fields. This semi-enclosed young ocean basin provides a unique opportunity to study the development of passive continental margins in order to examine the current status of that region. In addition to studies on the Sea itself, it includes those from related fields on the littoral zone. The book is of interest to geoscientists and non-specialists alike.
Download or read book Tectonic Faults written by Mark R. Handy and published by MIT Press. This book was released on 2007 with total page 461 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientists examine tectonic faulting on all scales--from seismic fault slip to the formation of mountain ranges--and discuss its connection to a wide range of global phenomena, including long-term climate change and evolution. Tectonic faults are sites of localized motion, both at the Earth's surface and within its dynamic interior. Faulting is directly linked to a wide range of global phenomena, including long-term climate change and the evolution of hominids, the opening and closure of oceans, and the rise and fall of mountain ranges. In Tectonic Faults, scientists from a variety of disciplines explore the connections between faulting and the processes of the Earth's atmosphere, surface, and interior. They consider faults and faulting from many different vantage points--including those of surface analysts, geochemists, material scientists, and physicists--and in all scales, from seismic fault slip to moving tectonic plates. They address basic issues, including the imaging of faults from Earth's surface to the base of the lithosphere and deeper, the structure and rheology of fault rocks, and the role of fluids and melt on the physical properties of deforming rock. They suggest strategies for understanding the interaction of faulting with topography and climate, predicting fault behavior, and interpreting the impacts on the rock record and the human environment. Using an Earth Systems approach, Tectonic Faults provides a new understanding of feedback between faulting and Earth's atmospheric, surface, and interior processes, and recommends new approaches for advancing knowledge of tectonic faults as an integral part of our dynamic planet.
Download or read book Crust Mantle and Lithosphere Asthenosphere Boundaries written by Gianluca Bianchini and published by Geological Society of America. This book was released on 2017-05-10 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 10-chapter volume encompasses contributions from a wide spectrum of Earth science disciplines, including geophysics, geodynamics, geochemistry, and petrology, to provide an overview of the nature and evolution of the crust-mantle and lithosphere-asthenosphere boundaries in different tectonic settings, combining studies that exploit different types of data and interpretative approaches. The integration of geochemical, geophysical, and geodynamic data sets and their interpretation provides a state-of-the-art summary of current understanding, and will serve as a blueprint for future research activities.
