ISBN: 9781334496646 - geologic reconnaissance of the northern coast ranges and klamath mountains, california: with a summary of the mineral resources (classic reprint) (3 resultados)

PAP. Condición: New. New Book. Shipped from UK. Established seller since 2000.

PAP. Condición: New. New Book. Shipped from UK. Established seller since 2000.

Paperback. Condición: New. Print on Demand. This book is a synthesis of available published and unpublished data on the geology of northwestern California, an area that includes most of the northern Coast Ranges and the Klamath Mountains geologic provinces in addition to the western part of the Sacramento Valley province. The text and maps are compilations of data, supplemented by reconnaissance during the period 1953-1957 by members of the U.S. Geological Survey. The geologic provinces differ markedly from the standpoint of topography, geologic history, and mineral deposits. The principal rocks of the Klamath Mountains range from early Paleozoic to middle Late Jurassic in age, and are intruded by granitic rocks that range from hornblende diorite to true granite in composition. In the northern Coast Ranges the principal rocks range from late Late Jurassic to Cretaceous in age, and there is little evidence that they have been intruded by granitic rocks. The principal rocks of both provinces, however, are intruded by abundant mafic and ultramafic rocks. The author describes four concentric, arcuate belts that are concave to the east within the Klamath Mountains province. From east to west the belts are (1) the eastern Paleozoic belt, (2) the central metamorphic belt, (3) the western Paleozoic and Triassic belt, and (4) the western Jurassic belt. The northern Coast Ranges are chiey graywackes and shales that range in age from late Late Jurassic to Late Cretaceous. The author describes a coastal belt of graywacke and shale west of the central belt of the Franciscan formation. The Sacramento Valley sequence is an orderly pile of graywacke, shale, and conglomerate that has been subdivided into the Knoxville formation of late Late Jurassic age, the Shasta series of Early Cretaceous age, and Upper Cretaceous rocks. The age of the Franciscan with respect to the Sacramento Valley sequence is not clearly known. The author concludes that this book provides a comprehensive overview of the geology of northwestern California, an area that has been studied only briey by various geologists, and whose meager knowledge precludes detailed description of lithology, thickness of section, age, and relations to adjacent rocks. This book is a reproduction of an important historical work, digitally reconstructed using state-of-the-art technology to preserve the original format. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in the book. print-on-demand item.…