Precambrian: Conterminous U.S.

Precambrian: Conterminous U.S.

Author: John C. Reed, Jr.

Publisher: Geological Society of America

Published: 1993

Total Pages: 752

ISBN-13: 081375447X

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This wide-ranging discussion of Precambrian rocks includes contributions from a diverse array of authors actively engaged in investigations of various aspects of U.S. Precambrian geology. Summary discussions by the editors of the five major chapters place these contributions in a logical regional framework.


The Rio Chama

The Rio Chama

Author: Paul W. Bauer

Publisher:

Published: 2021-12

Total Pages:

ISBN-13: 9781883905323

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In the course of the hundreds of Rio Chama rafting trips that we've logged during the last 30 years, none of us has ever had a bad trip. Such is the magic of the Rio Chama. No matter the weather, the water level, the season, the crowded Big Eddy boat ramp on a blistering Sunday afternoon, or even the coffee forgotten at home, the Rio Chama remains "The People's River." Its stunning beauty, plus its exceptional camping, user-friendly whitewater, and mostly predictable flows, combine to create one of the Southwest's premiere, multi-day, river running experiences.The spectacular, towering canyon walls of the Wild & Scenic section through the remote Chama River Canyon Wilderness is New Mexico's own "Grand Canyon." The geology of the Rio Chama is so exceptional that this river is ideally suited for a river guide with a geological theme. And so, following the release of the Rio Grande geologic river guide in 2011, we turned our (part-time) attention to the Rio Chama. Although most Rio Chama recreation is focused on the El Vado to Big Eddy stretch, thedecision was easily made to include the entire boatable section, from the highlands in Colorado to the confluence with the Rio Grande, as each section of the river displays its own visual spectacles and assortment of adventures. Plus, the geology is magnificent and diverse along the entire length of the river.


Proterozoic Crustal Evolution

Proterozoic Crustal Evolution

Author: K.C. Condie

Publisher: Elsevier

Published: 1993-02-03

Total Pages: 553

ISBN-13: 0080869092

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As a final product of the International Geological Correlation Program (IGCP) Project 217, this volume brings together significant advances in the understanding of Proterozoic crustal evolution. This IGCP Project focussed on nine research objectives: 1) Comparison of Archean and Proterozoic supracrustal assemblages to more fully understand differences between Archean and post-Archean tectonic regimes; 2) To more fully understand the geochemical differences between Archean and post-Archean sediments and to evaluate the various factors that control sediment composition; 3) From combined U/Pb zircon and whole-rock Sm/Nd studies, to see if the apparent 2.4-2.0 continental crust "generation gap" is real; 4) To employ new techniques in the dating of individual zircons to more fully understand Proterozoic tectonic history and the role of crustal reworking; 5) From trace element ratios and Nd isotopic data from basalts, to better understand Proterozoic mantle evolution; 6) To encourage more detailed studies of the anorogenic granite-anorthosite association to better understand its origin and significance in terms of crustal evolution; 7) From combined Nd, Pb, and Sr isotopic data, to more precisely estimate the amount of new continental crust formed during the Proterozoic; 8) To encourage joint P-T and geochronological studies of Proterozoic and high-grade terranes to better understand Proterozoic orogenesis: and 9) To try and understand why hydrothermal precious metal deposits are relatively rare in the Proterozoic compared to both the Archean and the Phanerozoic. The book should be of interest to professionals in the geosciences (especially geochemists, petrologists and structural geologists) and graduate students in the same fields.