Paleozoic subduction complex and Paleozoic–Mesozoic island-arc volcano-plutonic assemblages in the northern Sierra terrane
Richard E. Hanson, Gary H. Girty, David S. Harwood, Richard A. Schweickert, 2000. "Paleozoic subduction complex and Paleozoic–Mesozoic island-arc volcano-plutonic assemblages in the northern Sierra terrane", Great Basin and Sierra Nevada, David R. Lageson, Stephen G. Peters, Mary M. Lahren
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This field trip provides an overview of the stratigraphic and structural evolution of the northern Sierra terrane, which forms a significant part of the wall rocks on the western side of the late Mesozoic Sierra Nevada batholith in California. The terrane consists of a pre-Late Devonian subduction complex (Shoo Fly Complex) overlain by submarine arc-related deposits that record the evolution of three separate island-arc systems in the Late Devonian-Early Mississippian, Permian, and Late Triassic-Jurassic. The two Paleozoic arc packages and the underlying Shoo Fly Complex have an important bearing on plate-tectonic processes affecting the convergent margin outboard of the Paleozoic Cordilleran miogeocline, although their original paleogeographic relations to North America are controversial. The third arc package represents an overlap assemblage that ties the terrane to North America by the Late Triassic and helps constrain the nature and timing of Mesozoic orogenesis. Several of the fieldtrip stops examine the record of pre-Late Devonian subduction contained in the Shoo Fly Complex, as well as the paleovolcanology of the overlying Devonian to Jurassic arc rocks. Excellent glaciated exposures provide the opportunity to study a cross section through a tilted Devonian volcano-plutonic association. Additional stops focus on plutonic rocks emplaced during Middle Jurassic arc magmatism in the terrane, and during the main pulse of Cretaceous magmatism in the Sierra Nevada batholith to the east.
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Great Basin and Sierra Nevada, the second volume of the Geological Society of America Field Guide Series, focuses on the dynamic and spectacular geology of this region, providing the inspiring backdrop for the 2000 GSA Annual Meeting in Reno. This volume gives complete coverage of field trips held in conjunction with that meeting, and contains 20 chapters organized into three sections. The first section consists of 16 chapters arranged in geochronological order, beginning with the active tectonics of Lake Tahoe and the historical surface faulting and paleoseismicity of the central Nevada seismic belt, and ending with the Neoproterozoic glacial record of Death Valley. In between are chapters dealing with Basin and Range extension, Eocene magmatism, Mesozoic plutonism in the Sierra Nevada, Paleozoic subduction, and Ordovician stratigraphy, to name a few. The second section covers the geology of the Nevada Test Site and the nuclear-waste repository at Yucca Mountain. The last section is an invited field guide from the 1999 GSA Cordilleran Section meeting that covers the wines and geology of Napa Valley, California. Overall, Great Basin and Sierra Nevada is a comprehensive compilation of new and exciting research on this amazingly diverse region, with well-crafted guides to field localities of special interest. Full-color plates in some chapters make this guide an especially appealing and useful volume.