Whole-lithosphere shear during oblique rifting
نویسندگان
چکیده
Abstract Processes controlling the formation of continental whole-lithosphere shear zones are debated, but their existence requires that lithosphere is mechanically coupled from base to top. We document a dextral, zone in Death Valley region (DVR), southwest United States. Dextral deflections depth gradients lithosphere-asthenosphere boundary and Moho stacked vertically, defining 20–50-km-wide, lower lithospheric with ~60 km shear. These underlie an upper-crustal fault accrued dextral slip since ca. 8–7 Ma, when we infer began. This offset less than net on (~90 km, 13–0 Ma) total extension (~250 16–0 Ma). show that, before weak middle crust decoupled deformation mantle lithosphere. Between 16 7 detachment thinned, uplifted, cooled, thus strengthened crust, which exposed metamorphic core complexes collocated zone. Midcrustal strengthening layered vertically therefore enabled Where thick exists (as pre–16 Ma DVR), midcrustal probably necessary condition for
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ژورنال
عنوان ژورنال: Geology
سال: 2021
ISSN: ['0091-7613', '1943-2682']
DOI: https://doi.org/10.1130/g49603.1