Emplacement of the Santa Rita Flat Pluton as a pluton-scale saddle reef

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doi: 10.1130/0091-7613(2000)28<1115:EOTSRF>2.0.CO;2
Authors:Vines, John A.; Law, Richard D.
Author Affiliations:Primary:
Virginia Polytechnic Institute and State University, Department of Geological Sciences, Blacksburg, VA, United States
Volume Title:Geology (Boulder)
Source:Geology (Boulder), 28(12), p.1115-1118. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0091-7613
Publication Date:2000
Note:In English; illus.
Summary:Regional mapping indicates that the Middle Jurassic Santa Rita Flat pluton, exposed in the Inyo Range of eastern California, is situated within the core of a south-plunging synform defined by bedding in the surrounding metasedimentary wall rocks, which dip beneath the pluton. However, bedding in rocks preserved above the pluton defines a south-plunging antiform. Anisotropy of magnetic susceptibility analysis revealed that magnetic foliation within the pluton also defines a south-plunging antiform, and the accompanying magnetic lineation plunges subparallel to the axis of this antiform. Our data indicate that the pluton was initially intruded as a sill in the hinge zone of the enveloping synform. Subsequent vertical inflation of the sill resulted in upward doming of the overlying roof and formation of the antiform now observed at the current erosion level in the pluton and preserved roof rocks. Emplacement of the pluton at 164 ± 1.5 Ma (U-Pb zircon age) overlaps in time with regional thrust faulting and folding ca. 185-148 Ma recognized in the southern Inyo Range. We speculate that space for initial emplacement of the pluton was produced during folding by layer-parallel slip and hinge-zone dilation, producing a saddle reef-like structure.
Subsections:Igneous petrology
Subjects:Antiform folds; Emplacement; Faults; Folds; Geophysical methods; Geophysical surveys; Intrusions; Jurassic; Magnetic methods; Magnetic susceptibility; Mesozoic; Middle Jurassic; Paleomagnetism; Plutons; Surveys; Synform folds; Tectonics; Thrust faults; California; Inyo County California; Inyo Mountains; United States; White Mountains; Santa Rita Flat Pluton
Coordinates:N354500 N373000 W1154000 W1184500
Abstract Numbers:01M/3354
Record ID:2000075436
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
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