The Papoose Flat pluton, Inyo Mountains, California: A reassessment of the kinematics of deformation and emplacement history in the light of current fabric data
- Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Geological Sciences
- Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Geology and Geophysics
- Univ. of California, Santa Barbara, CA (United States). Dept. of Geology
- Univ. of Calgary, Alberta (Canada). Dept. of Geology and Geophysics
The Papoose Flat pluton of eastern California is characterized by intense crystal plastic deformation and dynamic recrystallization accompanied by stratigraphic attenuation around its western margin. Previously reported microstructures and crystal fabrics within quartz veins from the pluton's gneissic border facies and quartzites within the overlying aureole, indicated a dominant top-to-the-SE shear sense. Models proposed to account for this shear sense in these quartz-rich L-S tectonites have included: (a) magmatic wedging towards the NW beneath a static cover of sedimentary rocks, (b) SE directed overthrusting of the cover rocks during the pluton's cooling stage, and (c) synchronous magmatic wedging and overthrusting. New fabric analyses based on a more detailed field sampling program indicate that while the aureole quartzites display either symmetrical c-axis fabrics or asymmetric fabrics indicating a top-to-the-SE shear sense, the quartz veins in the gneissic border facies are characterized by asymmetric fabrics indicating a domainal (km scale) distribution of top-to-the-SE and top-to-the-NW shear senses. This domainal variation in shear sense is difficult to reconcile with a simple overthrusting model, but could be explained by a more complex model involving NW directed magmatic wedging accompanied and/or postdated by localized magma chamber inflation. Such localized inflation could result in a top-to-the-NW shear sense being superimposed on gneissic border facies quartz veins located beneath the NW dipping areas of the pluton's roof.
- OSTI ID:
- 5097973
- Report Number(s):
- CONF-9305259-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 25:5; Conference: 89. annual meeting of the Cordilleran Section and the 46th annual meeting of the Rocky Mountain Section of the Geological Society of America (GSA), Reno, NV (United States), 19-21 May 1993; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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Contact metamorphism associated with emplacement of the Papoose Flat pluton, Inyo Mountains, California
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