Proterozoic Crustal Evolution


Book Description

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.




The Eastern San Juan Mountains


Book Description

A companion to The Western San Juan Mountains (originally published in 1996), The Eastern San Juan Mountains details the physical environment, biological communities, human history, and points of interest in this rich and diverse mountain system. A natural division between the eastern and western slopes of the San Juans is the north-south line that runs approximately through Lake City, south of the crossing of the Piedra River by US Highway 160. In this super guidebook, twenty-seven contributors--all experts in their fields--artfully bring the geology, hydrology, animal and plant life, human histories, and travel routes of these eastern slopes to life. Designed to inform researchers, educators, and students about the region's complex systems, The Eastern San Juan Mountains also serves as an informative guidebook to accompany visitors along their travels on the Silver Thread National Scenic Byway, which stretches between South Fork and Lake City. The Eastern San Juan Mountains deserves a place next to The Western San Juan Mountains on the bookshelf of every naturalist, researcher, resident, educator, student, and tourist seeking a greater understanding of this marvelous place and its history.




Gold Metal Waters


Book Description

Gold Metal Waters presents a uniquely inter- and transdisciplinary examination into the August 2015 Gold King Mine spill in Silverton, Colorado, when more than three million gallons of subterranean mine water, carrying 880,000 pounds of heavy metals, spilled into a tributary of the Animas River. The book illuminates the ongoing ecological, economic, political, social, and cultural significance of a regional event with far-reaching implications, showing how this natural and technical disaster has affected and continues to affect local and national communities, including Native American reservations, as well as agriculture and wildlife in the region. This singular event is surveyed and interpreted from multiple diverse perspectives—college professors, students, and scientists and activists from a range of academic and epistemological backgrounds—with each chapter reflecting unique professional and personal experiences. Contributors examine both the context for this event and responses to it, embedding this discussion within the broader context of the tens of thousands of mines leaking pollutants into waterways and soils throughout Colorado and the failure to adequately mitigate the larger ongoing crisis. The Gold King Mine spill was the catalyst that finally brought Superfund listing to the Silverton area; it was a truly sensational event in many respects. Gold Metal Waters will be of interest to students and scholars in all disciplines, but especially in environmental history, western history, mining history, politics, and communication, as well as general readers concerned with human relationships with the environment. Contributors: Alane Brown, Brian L. Burke, Karletta Chief, Steven Chischilly, Becky Clausen, Michael A. Dichio, Betty Carter Dorr, Cynthia Dott, Gary Gianniny, David Gonzales, Andrew Gulliford, Lisa Marie Jacobs, Ashley Merchant, Teresa Montoya, Scott W. Roberts, Lorraine L. Taylor, Jack Turner, Keith D. Winchester, Megan C. Wrona, Janene Yazzie




Proterozoic Geology


Book Description













Ancient Supercontinents and the Paleogeography of Earth


Book Description

Ancient Supercontinents and the Paleogeography of Earth offers a systematic examination of Precambrian cratons and supercontinents. Through detailed maps of drift histories and paleogeography of each continent, this book examines topics related to Earth's tectonic evolution prior to Pangea, including plate kinematics, orogenic development, and paleoenvironments. Additionally, this book discusses the methodologies used, principally paleomagnetism and tectonostratigraphy, and addresses geophysical topics of mantle dynamics and geodynamo evolution over billions of years. Structured clearly with consistent coverage for Precambrian cratons, this book combines state-of-the-art paleomagnetic and geochronologic data to reconstruct the paleogeography of the Earth in the context of major climatic events such as global glaciations. It is an ideal, up-to-date reference for geoscientists and geographers looking for answers to questions surrounding the tectonic evolution of Earth. - Provides robust paleogeographies of Precambrian cratons based on high-quality paleomagnetic and geochronologic data and critically tested by global geological datasets - Includes links to updated databases for the Precambrian such as PALEOMAGIA and the Global Paleomagnetic Database (GPMDB) - Presents full-color maps of the drift histories of each continent as well as their paleogeographies - Discusses key questions regarding continental drift, the supercontinent cycle, and the geomagnetic dipole hypothesis and analyzes palaeography in the context of Earth's holistic evolution







Precambrian: Conterminous U.S.


Book Description

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.