Download or read book Continental Crust Structures on the Continental Margin of Western North America written by Henry V. Lyatsky and published by Springer. This book was released on 2006-04-10 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NE Pacific Ocean is considered the birthplace of many fundamental ideas for modern plate tectonics theory. In this book the orogenic belts of this region are discussed in a single, internally consistent tectonic concept. Geological information is considered the most reliable. Geophysical models are tested for compatibility with observable geological data. The new concept avoids force-fitting interpretations to preconceived assumptions regarding accreted far-traveled terranes in the Cordillera and continental-oceanic plate interactions in the entire region.
Download or read book The Geology of Continental Margins written by C.A. Burk and published by Springer. This book was released on 2013-12-20 with total page 976 pages. Available in PDF, EPUB and Kindle. Book excerpt: The continental margins of the world constitute the most impressive and largest physiographic feature of the earth's surface, and one of fundamentally great geological significance. Continental margins have been the subject of increasing attention in recent years, an interest focused by a body of new data that has provided new insights into their character. This interest was further stimulated by the realization that, in addition to the abundant living resources, continental margins contain petroleum and mineral resources that are accessible with existing technology. This realization, along with their basic geological importance, has provoked further research into the nature of continental margins throughout the world. A summary of these findings, as related to both recent and ancient continental margins, is the subject of this book. At various times in the past we had been approached individually to prepare a basic reference to continental margins; we then proposed to do such a volume jointly. However, the stimulus for the present volume eventually arose from a Penrose Conference arranged through the Geological Society of America. This conference was attended by specialists of numerous disciplines and from throughout the world, many of whom insisted that such a volume would be both timely and useful. Consequently, we agreed to undertake the task of assembling this book, with the objectives of making it available as soon and as inexpensively as possible.
Download or read book Crustal Structure of Rifted and Convergent Margins written by Daniel Lizarralde and published by . This book was released on 1997 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many of the most important processes that create and modify continental crust occur at continental margins, but recently has the scientific community acquired the necessary intrumentation to image crustal structure across margins in detail. In this thesis we investigate the crustal structure across the U.S. East Coast rifted margin and the convergent margin of southwestern Alaska using modern, deep-penetrating marine seismic reflection/refraction data. We consider U.S. East Coast margin transects along the shelf offshore Georgia and across the mid-Atlantic margin near Chesapeak bay. Results by other workers, based on data from these transects, have shown that voluminous volcanism accompanied formation of the rifted margin during continental breakup. Results presented in this thesis constrain the landward extent of rift-related magmatic emplacement. We find that magmatic intrusion and underplating of pre-existing continental crust occurs primarily in extended crust and that crustal extension is focused in a 75-km-wide region beneath the shelf and slope. The crust thinned by 50 to 80% within this interval and then seafloor spreading began with an unusually large volume of igneous crust production. The initial volcanic extrusives were emplaced subaerially and are now present beneath the sediments in a thick seaward-dipping wedge. We use post-stack depth migration to image this wedge and use the resulting image to consider the early subsidence of the margin. The geometry of the subaerially extruded rift volcanics suggest that the margin subsided rapidly once volncanism began. We infer from the subsidence, the along-margin distribution of magmatic material, and the across-margin localization of magmatic emplacement and deformation that the U.S. East Coast rift volcanics had an anomalously-hot mantle source whose distribution beneath the lithosphere prior to rifting was long (the length of the margin) but not deep. We speculate that the distribution of this material was controlled by topography at the base of the lithosphere inherited from the Paleozoic collision of North America and Africa. Our analysis of the southwestern Alaska convergent margin is based on data from the 1994 Aleutian seismic experiment. The crust of most of Alaska has been built through terrane accretion and arc magmatism, and this experiment was conducted to study the evolution of continental crust through these processes. We consider transects across the westernmost Alaska Peninsula margin, where subduction is occurring beneath protocontinental crust composed of oceanic-arc terranes accreted in the Cretaceous, and across Bristol Bay in the back arc region where the crust has undergone a number of geologic events since accretion. Across the Peninsula, we find that the velocity structure of the accreted terranes differs little from that of the Cenozoic Aleutian oceanic-arc crust west of the Peninsula determined along another transect of this experiment. The accreted oceanicarc terranes are considerably more mafic than continental crust and the process of accretion has apparently not modified the bulk composition of these terranes toward that of average continental crust. It is possible that Cenozoic arc magmatism has been more felsic in composition than that which formed the accreted terranes and the Aleutian oceanic arc to the west, and that these magmas have been emplaced primarily within the crust inboard of the accreted terranes which lie south of the currently active arc. The geology of the Bristol Bay region suggests that the crustal components here had an origin similar to that of the Alaska Peninsula margin- that is, accreted terranes. We find, however, that the crust beneath Bristol Bay has a typically continental velocity structure. If this crust originally had a structure similar to the Alaska Peninsula margin, then at least two processes must have occured to affect the transformation to its current structure: crustal thickening and removal of the mafic lower crust. The geologic events that have affected this region since accretion are consistent with such and evolution.
Download or read book New Publications of the Geological Survey written by Geological Survey (U.S.) and published by . This book was released on 1988 with total page 748 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physical Geology written by Steven Earle and published by . This book was released on 2016-08-12 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a discount Black and white version. Some images may be unclear, please see BCCampus website for the digital version.This book was born out of a 2014 meeting of earth science educators representing most of the universities and colleges in British Columbia, and nurtured by a widely shared frustration that many students are not thriving in courses because textbooks have become too expensive for them to buy. But the real inspiration comes from a fascination for the spectacular geology of western Canada and the many decades that the author spent exploring this region along with colleagues, students, family, and friends. My goal has been to provide an accessible and comprehensive guide to the important topics of geology, richly illustrated with examples from western Canada. Although this text is intended to complement a typical first-year course in physical geology, its contents could be applied to numerous other related courses.
Download or read book Continental Tectonics written by National Research Council and published by National Academies Press. This book was released on 1980-02-01 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geophysical Framework of the Continental United States written by Louis Charles Pakiser and published by Geological Society of America. This book was released on 1989 with total page 843 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review and evaluation of our knowledge of the structure of the crust and upper mantle of the continental United States, exclusive of Alaska, as determined from geophysical observations. Covers geophysical methods of studying the crust and upper mantle; a region-by-region review of crustal and upper-mantle structure; continental overviews based on the different geophysical methods; and geologic and petrologic syntheses based largely on the geophysical results.
Download or read book Tectonic Growth of a Collisional Continental Margin written by Kenneth D. Ridgway and published by Geological Society of America. This book was released on 2007 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The convergent margin of southern Alaska is considered one of the type areas for understanding the growth of continental margins through collisional tectonic processes. Collisional processes that formed this margin were responsible for multiple episodes of sedimentary basin development, subduction complex growth, magmatism, and deformation. Two main collisional episodes shaped this Mesozoic-Cenozoic continental margin. The first event was the Mesozoic collision of the allochthonous Wrangellia composite terrane. This event represents the largest addition of juvenile crust to western North America in the past 100 m.y. The second event is the ongoing collision of the Yakutat terrane along the southeastern margin of Alaska. This Cenozoic event has produced the highest coast mountain range on Earth (Saint Elias Mountains), the Wrangell continental arc, and sedimentary basins throughout southern Alaska. Active collisional processes continue to shape the southern margin of Alaska, mainly through crustal shortening and strike-slip deformation, large-magnitude earthquakes, and rapid uplift and exhumation of mountain belts and high sedimentation rates in adjacent sedimentary basins. This volume contains 24 articles that integrate new geophysical and geologic data, including many field-based studies, to better link the sedimentary, structural, geochemical, and magmatic processes that are important for understanding the development of collisional continental margins."--Publisher's website.
Download or read book Principles of Practical Tectonic Analysis of Cratonic Regions written by Henry Lyatsky and published by Springer. This book was released on 2006-04-10 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt: Steep crystalline-basement faults, commonly indicated by potential-field anomalies, played a crucial role in evolution of continental cratonic platforms. In the Phanerozoic Western Canada Sedimentary Province, history of crustal block movements and warps is reconstructed from the distribution of depocenters, lithofacies and structures in structural-formational étages in sedimentary cover. Each étage is a rock succession formed during a particular tectonic stage; regional tectonic restructuring closes each stage, and the next stage represents a new tectonic regime. Practical tectonic analysis, based on observation of rocks and geophysical data, is a reliable guide for deciphering a region's geologic history and for resource exploration.
Download or read book Tectonics of Circum Pacific Continental Margins written by Jean Aubouin and published by VSP. This book was released on 1990-12 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the structure and nature of movements within the Earth's crust has become increasingly important as we try to understand the history of the Earth and try to use this knowledge as a key to events in the future. This is especially relevant to those everincreasing communities populating the edges of the Pacific Ocean. This collection of papers deals with the tectonic modelling and evolution in some of the most seismically active regions in the world. Structural and stratigraphical analysis, together with geophysical, petrological and geochemical data give us some insight into tectonic events from the past and how they affected ancient landforms, and gives us a clearer understanding of earth movements and, therefore, allows us to predict catastrophic events such as earthquakes with greater accuracy.
Download or read book Bibliography of North American Geology written by and published by . This book was released on 1966 with total page 1126 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1919/28 cumulation includes material previously issued in the 1919/20-1935/36 issues and also material not published separately for 1927/28. 1929/39 cumulation includes material previously issued in the 1929/30-1935/36 issues and also material for 1937-39 not published separately.
Download or read book Crustal Cross Sections from the Western North American Cordillera and Elsewhere written by Robert Bruce Miller and published by Geological Society of America. This book was released on 2009 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Exposed crustal cross sections provide a unique direct view of continental crust, and are a major source of insights into variations in lithologic and geochemical composition, structural style, metamorphism, plutonism, and rheology with progressive depth through the crust. This volume provides a synthesis of crustal cross sections with a special emphasis on Phanerozoic sections from the western North American Cordillera, supplemented by articles on lower- and mid-crustal sections through Proterozoic crust in North America and Australia, and the classic crustal section of Fiordland, New Zealand. Many of the papers describe multidisciplinary research on crustal sections and include data from various combinations of structural analysis, geochemistry, geothermobarometry, geochronology, geophysics, and other disciplines. The volume also discusses common problems for the interpretation of crustal cross sections, including how sections that expose deep-crustal rocks are eventually exhumed, and leading to the conclusion that there is no simple 'standard model' for continental crust. This volume will be useful to those interested in structural geology, tectonics, geodynamics, regional geology, petrology, geochemistry/isotope geology, and geophysics."--Pub. desc.
Download or read book Geology of North America An Overview written by Albert W. Bally and published by Geological Society of America. This book was released on 1989 with total page 633 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summaries of the major features of the geology of North America and the adjacent oceanic regions are presented in 20 chapters. Topics covered include concise reviews of current thinking about Precambrian basement, Phanerozoic orogens, cratonic basins, passive-margin geology of the Atlantic and Gulf Coast regions, marine and terrestrial geology of the Caribbean region and economic geology.
Download or read book Studies in Continental Margin Geology written by Joel S. Watkins and published by . This book was released on 1983 with total page 844 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Ocean Basins Their Structure and Evolution written by Open Open University and published by Elsevier. This book was released on 1998-01-26 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an invaluable textbook, prepared by the Open University team and designed so that it can be read on its own or as part of the OU course. This second edition has been fully revised and updated including new colour illustrations increasing the striking spread of full colour diagrams throughout the book. The clarity of the text has been improved, providing comprehensive coverage of the evolution of ocean basins and their structure in a clear, concise manner aimed specifically at the student market.In this second edition the technological advances in fields as diverse as:- deep-towed instruments for `sniffing' hydrothermal plumes- mapping the sea-floor by sophisticated sonar techniques - three-dimensional imaging of crustal structure by seismic tomography- the use of satellites for navigation, and for making precise measurements of the height of the sea-surfaceThe first chapters describe the processes that shape the ocean basins, determine the structure and composition of oceanic crust and control the major features of continental margins. How the 'hot springs' of the oceanic ridges cycle chemical elements between seawater and oceanic crust is then explored. Sediment distributions are examined next, to demonstrate how sediments can preserve a record of past climatic and sea-level changes. Finally, the role of the oceans as an integral part of global chemical changes is reviewed. - High quality full colour diagrams - Substantial chapter summaries ideal for revision - Answers, hints and notes for questions at back of the book
Download or read book Crustal Properties Across Passive Margins written by C. E. Keen and published by Elsevier. This book was released on 2013-10-22 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developments in Geotectonics, 15: Crustal Properties across Passive Margins covers the papers presented at the symposium ""Crustal Properties across Passive Margins"", held at Dalhousie University in Halifax, Nova Scotia on June 19-23, 1978. The book focuses on theoretical modelling of the rheological properties in the upper mantle beneath oceans and continents and stratigraphic studies of the sedimentary basins. The selection first offers information on seismic refraction study of the continental edge off the Eastern United States and gravity field of the U.S. Atlantic continental margin. Topics include crustal sections, inner and outer quiet zones, alternative models and complications, gravity models, free-air anomaly map, and the ocean-continent transition zone. The text then takes a look at the geologic history of the passive margin off New England and the Canadian Maritime Provinces and geophysical observations bearing upon the origin of the Newfoundland Ridge. The manuscript elaborates on the age and origin of the deepest correlative structures recognized off Canada and Europe and geophysical transects of the Labrador Sea. Discussions focus on magnetics and gravity, stratigraphic control, consequences regarding subduction or rifting, and deep structures of the Grand Banks of Newfoundland. The selection is a dependable reference for readers interested in crustal properties across passive margins.
Download or read book New Publications of the U S Geological Survey written by and published by . This book was released on 1987 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
