Archean Crustal Evolution

Archean Crustal Evolution

Author: K.C. Condie

Publisher: Elsevier

Published: 1994-11-11

Total Pages: 543

ISBN-13: 0080869106

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The integration of Tectonics/Geochemistry, up-to-date reviews by leading scientists as well as a broad topical coverage of the Archean, are some of the features of this particular volume. As geochronology has progressed in the last 20 years, the Archean has continued to attract interest. Advancements in the understanding of Archean crustal and mantle evolution have progressed rapidly since the first International Archean Symposium in Western Australia (1970). The landmark for the Archean was the NATO Advanced Study Institute at Leicester (1975). At this meeting the Archean truly "came of age". Investigators from many different disciplines focused their expertise on the early history of the earth. For the first time, the nature of the atmosphere, oceans, and life during the Archean was an important part of an Archean symposium. During the most recent Archean Symposium in Perth in 1990, there was a shift in interest from field and trace element data to the new rapidly evolving high-precision U/Pb geochronology of Archean rocks and to detailed structural studies of both low and high grade Archean terrains. The terrane concept so widely applied to the Phanerozoic was proposed for the Archean Yilgarn Province in Western Australia and is now widely accepted for the Archean (as evident by the articles in this book). Plate tectonics is now widely accepted as the principal process that controls the history of continents and oceans. There are, though, well substantiated differences between Archean and post-Archean rocks that indicate that Archean tectonic regimes must have differed in some respects from modern ones. The question of how and to what degree did Archean plate tectonics differ from modern plate tectonics is treated in many of the chapters of this book. Altogether, the editor has presented a selection of articles that provide a fascinating insight into the latest observations in this field.


Trondhjemites, Dacites, and Related Rocks

Trondhjemites, Dacites, and Related Rocks

Author: F. Barker

Publisher: Elsevier

Published: 2013-10-22

Total Pages: 676

ISBN-13: 1483289605

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Developments in Petrology, 6: Trondhjemites, Dacites, and Related Rocks focuses on the geology, geochemistry, and petrology of several kinds of trondhjemites, dacites, and genetically related rocks. The selection first elaborates on the definition, environment, and hypotheses of origin of trondhjemite; a review of the mineralogy and chemistry of tertiary-recent dacitic, latitic, rhyolitic, and related salic volcanic rocks; and some trace elements in trondhjemites and their implications to magma genesis and paleotectonic setting. Discussions focus on tectonic environments and trace element patterns, selection and reliability of trace elements, interrelationships between mineralogy and chemistry, and regional variations of dacitic and rhyolitic magmas. The publication then tackles strontium isotope geochemistry of late Archean to late Cretaceous tonalites and trondhjemites; Archean gray gneisses and the origin of the continental crust in West Greenland; and metamorphic development of early Archean tonalitic and trondhjemitic gneisses in Saglek Area, Labrador. The book examines the petrology, geochemistry, and origin of the Sparta quartz dioritetrondhjemite complex; reconnaissance geochemistry of Devonian island-arc volcanic and intrusive rocks in West Shasta District, California; and origin of the Twillingate trondhjemite in North-Central Newfoundland. The selection is highly recommended for geologists and geochemists wanting to explore trondhjemites, dacites, and genetically related rocks.