Formation of the Sierra Nevada Batholith

This comprehensive field guide takes you on a six-day, west-to-east geologic journey across the Mesozoic magmatic arc of the central Sierra Nevada in California. It contains a summary of field, structural, geochemical, and geochronologic data collected by a number of researchers on individual intrusions (Guadalupe Igneous Complex and nearby Hornitos pluton, Fine Gold Intrusive Suite, Yosemite Valley Intrusive Suite, Tuolumne Intrusive Complex). This guide also includes data on the basement terranes intruded by these intrusions, Mesozoic volcanic-sedimentary sections, and data derived of several Sierra Nevada-wide data sets (plutonic, volcanic and sedimentary geochronology, strain analyses, structures, and geochemistry). Syntheses of these data sets at the end of the guide focus on magmatic processes from the mineral to the arc scale, as well as contemporaneous tectonics, and the tempos controlling magmatism, deformation, exhumation, and erosion/redeposition in the Sierran arc.
Day 1: Guadalupe Igneous Complex
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Published:January 01, 2014
Abstract
We begin our journey through the Mesozoic Sierran arc with an examination of the Guadalupe Igneous Complex, a layered Jurassic pluton that intrudes into largely oceanic materials in the Foothills Terrane of the Western Metamorphic belt (Figs. 1-1 and 1-2). The Guadalupe Igneous Complex is an intuitively pleasing target to begin with because of its outboard (western) location and because it consists of some of the most mafic (>8% MgO gabbros) and felsic (high-silica and high-K2O granophyres and rhyolites) igneous units that we will see on this trip and thus raises some longstanding petrologic questions about the connections between mafic and felsic granitoids in arcs. It is also an exciting objective because of the preservation of its likely feeder zone (the Hornitos pluton), internal layering, and capping volcanics (Fig. 1-2)…
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- Mariposa Formation
- Guadalupe Complex
- Hornitos Pluton