Composition, Deep Structure and Evolution of Continents

Composition, Deep Structure and Evolution of Continents PDF Author: Robert Dirk van der Hilst
Publisher:
ISBN: 9780444503091
Category : Continents
Languages : en
Pages : 342

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Composition, Deep Structure and Evolution of Continents

Composition, Deep Structure and Evolution of Continents PDF Author: R.D. van der Hilst
Publisher: Elsevier
ISBN: 0080529453
Category : Science
Languages : en
Pages : 355

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Book Description
The ensemble of manuscripts presented in this special volume captures the stimulating cross-disciplinary dialogue from the International Symposium on Deep Structure, Composition, and Evolution of Continents, Harvard University, Cambridge, Massachusetts, 15-17 October 1997. It will provide an update on recent research developments and serve as a starting point for research of the many outstanding issues.After its formation at mid-oceanic spreading centers, oceanic lithosphere cools, thickens, and subsides, until it subducts into the deep mantle beneath convergent margins. As a result of this continuous recycling process oceanic lithosphere is typically less than 200 million years old (the global average is about 80 Myr). A comprehensive, multi-disciplinary study of continents involves a wide range of length scales: tiny rock samples and diamond inclusions may yield isotope and trace element signatures diagnostic for the formation age and evolution of (parts of) cratons, while geophysical techniques (e.g., seismic and electromagnetic imaging) constrain variations of elastic and conductive properties over length scales ranging from several to many thousand kilometers. Integrating and reconciling this information is far from trivial and, as several papers in this volume document, the relationships between, for instance, formation age and tectonic behavior on the one hand and the seismic signature, heat flow, and petrology on the other may not be uniform but may vary both within as well as between cratons. These observations complicate attempts to determine the variations of one particular observable (e.g., heat flow, lithosphere thickness) as a function of another (e.g., crustal age) on the basis of global data compilations and tectonic regionalizations.Important conclusions of the work presented here are that (1) continental deformation, for instance shortening, is not restricted to the crust but also involves the lithospheric mantle; (2) the high wavespeed part of continental lithospheric mantle is probably thinner than inferred previously from vertically travelling body waves or form global surface-wave models; and (3) the seismic signature of ancient continents is more complex than expected from a uniform relationship with crustal age.

Composition, Deep Structure and Evolution of Continents

Composition, Deep Structure and Evolution of Continents PDF Author: Robert Dirk van der Hilst
Publisher:
ISBN: 9780444503091
Category : Continents
Languages : en
Pages : 342

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Book Description


A Tale of Two Cratons

A Tale of Two Cratons PDF Author: A. G. Jones
Publisher: Gulf Professional Publishing
ISBN: 9780444516145
Category : Science
Languages : en
Pages : 522

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Book Description
Given the established nature of geoscientific knowledge of the Kaapvaal craton compared to the Slave craton, and given the exciting new interdisciplinary results coming from the Kaapvaal Project and from Slave craton studies, scientists working on both cratons were brought together in a workshop to compare and contrast the nature of these two cratons. Of the 54 papers presented at the workshop, 24 are included in this volume. There are clearly major similarities and differences between these two Archean cratons. The crust of both was predominantly formed in the Mesoarchean. Both contain crustal sections consisting of terranes of different ages welded together by Archean accretionary events. Both crustal sections are underlain by lithospheric mantle sections consisting of peridotites that experienced extensive partial melt extraction between 2.9 Ga and 3.2 Ga, but this is where the similarities between the cratons end. One of the most striking differences between the Slave and Kaapvaal cartons is the apparent seismic homogeneity of the Kaapvaal craton's SCLM whereas the Slave craton is seismically layered. The seismic layering in the centre of the craton correlates laterally and with depth with electrical layering and geochemical layering. Taken together, these differences suggest that SCLM formation was different for the two cratons, implying that the search for a single causative formation process is bound to fail. Reprinted from the journal Lithos Volume 71, numbers 2-4.

Encyclopedia of Solid Earth Geophysics

Encyclopedia of Solid Earth Geophysics PDF Author: Harsh Gupta
Publisher: Springer Science & Business Media
ISBN: 904818701X
Category : Science
Languages : en
Pages : 1579

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Book Description
The past few decades have witnessed the growth of the Earth Sciences in the pursuit of knowledge and understanding of the planet that we live on. This development addresses the challenging endeavor to enrich human lives with the bounties of Nature as well as to preserve the planet for the generations to come. Solid Earth Geophysics aspires to define and quantify the internal structure and processes of the Earth in terms of the principles of physics and forms the intrinsic framework, which other allied disciplines utilize for more specific investigations. The first edition of the Encyclopedia of Solid Earth Geophysics was published in 1989 by Van Nostrand Reinhold publishing company. More than two decades later, this new volume, edited by Prof. Harsh K. Gupta, represents a thoroughly revised and expanded reference work. It brings together more than 200 articles covering established and new concepts of Geophysics across the various sub-disciplines such as Gravity, Geodesy, Geomagnetism, Seismology, Seismics, Deep Earth Processes, Plate Tectonics, Thermal Domains, Computational Methods, etc. in a systematic and consistent format and standard. It is an authoritative and current reference source with extraordinary width of scope. It draws its unique strength from the expert contributions of editors and authors across the globe. It is designed to serve as a valuable and cherished source of information for current and future generations of professionals.

8th International Kimberlite Conference: The J. Barry Hawthorne volume

8th International Kimberlite Conference: The J. Barry Hawthorne volume PDF Author: Roger H. Mitchell
Publisher: Gulf Professional Publishing
ISBN: 9780444517777
Category : Diamonds
Languages : en
Pages : 982

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Book Description
Volume 2, dedicated to Barry Hawthorne, presents papers concerned with the genesis of eclogites, the mineralogy of diamond and its inclusions, exploration methods for kimberlite, the geochemistry of the upper mantle and the character of cratons.

The Early Earth

The Early Earth PDF Author: C. M. R. Fowler
Publisher: Geological Society of London
ISBN: 9781862391093
Category : Science
Languages : en
Pages : 378

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U.S. Geological Survey Circular

U.S. Geological Survey Circular PDF Author:
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 152

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The Continental Crust

The Continental Crust PDF Author: SR Taylor
Publisher: Wiley-Blackwell
ISBN: 9780632011483
Category : Science
Languages : en
Pages : 328

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Book Description
Graduates in geology, geochemistry and geophysics will find this volume in the Geoscience Texts series a valuable reference text. The book begins by describing the known composition of the present upper crust, then deals with possible compositions for the total crusts and the inferred composition of the lower crust. The question of the uniformity of crustal composition throughout geological time is discussed. The rate of growth of the crust through time is assessed, and the effects of the extraction of the crust on mantle compositions are considered. Finally, the question of early pre-geological crusts on the Earth is debated, and comparisons are given with crusts on the Moon, Mercury, Mars, Venus and the Galilean Satellites.

Gondwana Research

Gondwana Research PDF Author:
Publisher:
ISBN:
Category : Geology, Stratigraphic
Languages : en
Pages : 688

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Office of Science and Technology policy

Office of Science and Technology policy PDF Author: United States. Congress. House. Committee on Appropriations. Subcommittee on HUD-Independent Agencies
Publisher:
ISBN:
Category : United States
Languages : en
Pages : 860

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Book Description