Download or read book Tectonics of the East Pacific Rise 5 to 12 S written by David Kenerson Rea and published by . This book was released on 1974 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: The portion of the East Pacific Rise (EPR) between 5° and 12°S can be subdivided into three areas by fracture zones that offset the rise axis at about 6.5°S and 9°S. In all three regions, the spreading axis of the EPR is defined by a topographic block 300 to 350 m high and about 15 km wide. The axial block commonly has subordinate peaks or shoulders on each flank that vary up to 5 km wide. Analysis of linear magnetic anomalies in the southern of the three areas suggests that sea-floor spreading has been occurring at rates of 80 mm/y to the west and 77 mm/y to the east during the last 1.7 million years (my). The rise axis is offset in two places about 10 km. These displacements are interpreted to be the result of discrete jumps of the site of spreading activity. Reconnaissance data from the east flank of the EPR indicate that spreading activity on this portion of the rise began just over 8 my ago when the site of crustal accretion jumped westward from the now dormant Galapagos Rise. About 4.6 my ago the section of rise crest between approximately 10.5°S and the 9°S fracture zone jumped westward a distance of at least 10 km, isolating the pre-existing axial block. By 1.7 my ago, this axial offset no longer existed, implying a relatively westward migration of the rise axis south of 10.5° during the period from 4.6 to 1.7 my ago. The two offsets of the present axis occurred between 1.6 and 0.9 my ago and 0.7 my ago and the present in the north and south, respectively. The formation of the axial block, its associated shoulders and the abyssal topography, apparently consisting of tilted fault blocks with steep sides facing the axis, can be explained by an empirical model. This model combines extrusion of basalt along the spreading axis to form the axial block and rotational faulting to form the shoulders of the block and then lower the shoulders to merge with the abyssal topography of the uppermost rise flanks. In the region north of the 6.5°S fracture zone, seismic activity on the rise crest, combined with topographic information, suggests that the EPR axis is unstable here and that it is in the process of reorienting to a more stable regional trend. Identification and mapping of magnetic anomalies in the vicinity of 6°S reveal a spreading rate of about 77 mm/y, an episode of oblique spreading that occurred 1.7 my ago, and a 10 km westward jump of the axis which occurred since 0.7 my ago. The fracture zone at 6.5°S offsets the EPR axis 55 km right laterally. Both the bathymetric and magnetic expression of this fracture zone are markedly reduced a few tens of kilometers away from its active portion, implying that some change in the processes forming the fracture zone occurred about 0.3 my ago. Between the fracture zones at 6.5° and 9°S, two deactivated segments of the rise axis, each about 40 km long, occur 90 and 65 km west of the currently active axis. These inactive axial segments were isolated by eastward jumps of the spreading center. The more northerly jump, along 6.5°S, occurred 0.3 my ago and spanned 68 km. The other, along 7°S, covered a similar distance and is either just completed or still going on. Reconnaissance data from this part of the EPR suggests that sea-floor spreading began here about 6.5 my ago and has been continuing at a rate of approximately 78 mm/y.
Download or read book Tectonics of the East Pacific Rise 50 to 120S written by David Kenerson Rea and published by . This book was released on 1975 with total page 310 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 Tectonic Globaloney written by N. Christian Smoot and published by Author House. This book was released on 2012-05-30 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Forty-five years after the synthesis of the plate tectonic hypothesis, much newer and better information has been gathered by the seagoers of the world. Contrary to popular opinion among earth scientists, the purveyors of plate tectonics are the present-day snake oil salesmen. This null hypothesis is fraught with misinformation and misconceptions. It is in need of a massive make-over. Midocean ridge spreading does not occur universally, especially in Iceland and the North Pacific basin. Deep earthquakes do not define a descending slab; in fact, do not even occur in most places along the trenches. Therefore, subduction does not occur. Continental drift is a figment of overly active imaginations, and Gondwana is an even greater figment. India has been in place for several billion years rather than wandering around. Index fossils like Lystrosaurus and Cynognathus are misused, misdated, and show nothing. Land bridges have surfaced and been submerged many times over the years allowing for free passage of fauna and flora. Fracture zones, rather than showing the direction of seafloor spreading, leave nothing more than a pattern of at least four different directions on the ocean floor as they intersect in a random fashion. The Chicxulub crater is not the result of a bolide strike, and this was known from the get-go. In 2004 the first edition of Tectonic Globaloney was published. Since that time much new information has been gathered and published. The Ocean Drilling Program has gone defunct as the owners of that program finally realized/admitted that they were not recovering basement material, self-admitting that only eight off-ridge cores had ever reached real basement. Therefore, the age of the ocean floor was unknown and the magnetic anomalies are not ground-truthed. The time has come for the field hands to take over and replace the ideas mostly derived by the geophysicists. Plate tectonics does not work.
Download or read book Tectonics and Metamorphism written by Bozzano G Luisa and published by Elsevier. This book was released on 1976-01-01 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tectonics and Metamorphism
Download or read book Soft Plate and Impact Tectonics written by António Ribeiro (prof) and published by Springer Science & Business Media. This book was released on 2002-04-24 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a historical perspective on plate tectonics. In doing so it discusses the foundations of rigid plate tectonics and the limitations of this approach. This classic approach explains the data at a level of 95 % precision. The authors explain data anomalies as a result of the discrepancies between spatial geodetical data and rigid kinematics in oceans. Data and its interpretation from various disciplines are pulled together in this book.
Download or read book Cenozoic History and Paleoceanography of the Central Equatorial Pacific Ocean written by Tjeerd Hendrik Van Andel and published by Geological Society of America. This book was released on 1975 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Ocean Drilling Program written by Ocean Drilling Program and published by . This book was released on 1993 with total page 1038 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contributions from the Scripps Institution of Oceanography written by Scripps Institution of Oceanography and published by . This book was released on 1977 with total page 1296 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reprints from various publications.
Download or read book Nazca Plate written by LaVerne D. Kulm and published by Geological Society of America. This book was released on 1981-01-01 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt: A volume dedicated to George P. Woollard.
Download or read book Tectonics of the East Pacific Rise written by Sang-Mook Lee and published by . This book was released on 1995 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: The global mid-ocean ridge system is one of the most striking geological features on the surface of the Earth. In this system, the East Pacific Rise (EPR) is the fastest spreading ridge and is thus considered as the most active magmatically among the plate boundaries. In January and February of 1988, an extensive survey by the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution was conducted along the EPR between 9°05' and 9°55'N to study the crustal structure of the axial region. This thesis, the result of that cruise, comprises four main topics: (1) characterization of normal faulting from Sea Beam bathymetric data, (2) application of mechanical models to explore the hypothesis that buoyancy arising from crustal magma chambers and gravitational spreading of the upper crust are the principal processes leading to the initiation and development of normal faults, (3) investigation of seafloor magnetization anomalies to constrain upper crustal structure, and (4) analysis of gravity anomalies to examine possible correlations between observed variations in seafloor manifestations of volcanism and deformation and underlying structure. Thus, each topic focuses on different levels of the mid-ocean ridge. Together with the results of seismic and other observations, the findings are woven into a better understanding of the tectonic processes and structure of fastspreading mid-ocean ridges.
Download or read book Tectonic Magmatic Hydrothermal and Biological Segmentation of Mid ocean Ridges written by C. J. MacLeod and published by Geological Society of London. This book was released on 1996 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Surge Tectonics A New Hypothesis of Global Geodynamics written by Arthur A. Meyerhoff and published by Springer Science & Business Media. This book was released on 1996-08-31 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: TECTONlCS AND PHYSICS Geology, although rooted in the laws of physics, rarely has been taught in a manner designed to stress the relations between the laws and theorems of physics and the postulates of geology. The same is true of geophysics, whose specialties (seismology, gravimetIy, magnetics, magnetotellurics) deal only with the laws that govern them, and not with those that govern geology's postulates. The branch of geology and geophysics called tectonophysics is not a formalized discipline or subdiscipline, and, therefore, has no formal laws or theorems of its own. Although many recent books claim to be textbooks in tectonophysics, they are not; they are books designed to explain one hypothesis, just as the present book is designed to explain one hypothesis. The textbook that comes closest to being a textbook of tectonophysics is Peter 1. Wyllie's (1971) book, The Dynamic Earth. Teachers, students, and practitioners of geology since the very beginning of earth science teaching have avoided the development of a rigorous (but not rigid) scientific approach to tectonics, largely because we earth scientists have not fully understood the origin of the features with which we are dealing. This fact is not at all surprising when one considers that the database for hypotheses and theories of tectonics, particularly before 1960, has been limited to a small part of the exposed land area on the Earth's surface.
Download or read book Tectonics of Asia Northern Central and Eastern Asia written by Oleg V. Petrov and published by Springer Nature. This book was released on 2021-03-03 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book provides the results of tectonic, geological and geophysical studies of Northern, Central and Eastern Asia obtained over the last 20 years, and a Tectonic map for this area overview as well as essays on its geodynamic evolution. These new results were obtained by an international team of specialists within the project “Atlas of geological maps of Central Asia and adjacent areas,” scale 1: 2,500,000, initiated in 2003 by geological surveys of Russia, China, Mongolia, Kazakhstan and South Korea under the auspices of the CGMW. The most of the book contains the descriptions of the tectonic structure of major geological regions of Asia, such as the Ural, Sayan-Baikal and Tien Shan orogenic systems. The tectonic structure of the Pamirs, Turan Plate, Mongolia, Southern China, Korea and other regions is also discussed. The book contains maps of gravity and magnetic anomalies, sketch maps of deep structures of the area, and the geotransect crossing the most important geological structures of Asia. The final chapter of the book describes the tectonic evolution of the Central Asian Orogenic Belt from the Neoproterozoic to the Mesozoic.
Download or read book Faulting and Magmatism at Mid Ocean Ridges written by W. Roger Buck and published by American Geophysical Union. This book was released on 1998-02-04 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book can benefit the nonspecialist who wants to keep up with work on magmatism and tectonics, as well as researchers working on mid-ocean ridges."--BOOK JACKET.
Download or read book Investigating Seafloors and Oceans written by Antony Joseph and published by Elsevier. This book was released on 2016-12-08 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt: Investigating Seafloors and Oceans: From Mud Volcanoes to Giant Squid offers a bottom-to-top tour of the world’s oceans, exposing the secrets hidden therein from a variety of scientific perspectives. Opening with a discussion of the earth’s formation, hot spots, ridges, plate tectonics, submarine trenches, and cold seeps, the text goes on to address such topics as the role of oceans in the origin of life, tidal bore, thermal effects, ecosystem services, marine creatures, and nutraceutical and pharmaceutical resources. This unique reference provides insight into a wide array of questions that researchers continue to ask about the vast study of oceans and the seafloor. It is a one-of-a-kind examination of oceans that offers important perspectives for researchers, practitioners, and academics in all marine-related fields. Includes chapters addressing various scientific disciplines, offering the opportunity for readers to gain insights on diverse topics in the study of oceans Provides scientific discussion on thermo-tolerant microbial life in sub-seafloor hot sediments and vent fields, as well as the origin of life debates and the puzzles revolving around how life originated Includes detailed information on the origin of dreaded episodes, such as volcanic eruptions, earthquakes, tsunamis, internal waves and tidal bores Contains information on the contribution of the oceans in terms of providing useful nutraceutical and pharmaceutical products
Download or read book Tectonic Development of the Eastern Mediterranean Region written by A. H. F. Robertson and published by Geological Society of London. This book was released on 2006 with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Eastern Mediterranean region is a classic area for the study of tectonic processes and settings related to the development of the Tethyan orogenic belt. The present set of research and synthesis papers by earth scientists from countries in this region and others provides an up-to-date, interdisciplinary overview of the tectonic development of the Eastern Mediterranean region from Precambrian to Recent. Key topics include continental rifting, ophiolite genesis and emplacement, continental collision, extensional tectonics, crustal exhumation and intra-plate deformation (e.g. active faulting). Alternative tectonic reconstructions of the Tethyan orogen are presented and discussed, with important implications for other regions of the world. The book will be an essential source of information and interpretation for academic researchers (geologists and geophysicists), advanced undergraduates and also for industry professionals, including those concerned with hydrocarbons, minerals and geological hazards (e.g. earthquakes).
