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Full-Text Articles in Tectonics and Structure
Constraints On Present-Day Basin And Range Deformation From Space Geodesy, Jeffrey Lee, Timothy H. Dixon, Stefano Robaudo, Marith C. Reheis
Constraints On Present-Day Basin And Range Deformation From Space Geodesy, Jeffrey Lee, Timothy H. Dixon, Stefano Robaudo, Marith C. Reheis
All Faculty Scholarship for the College of the Sciences
We use new space geodetic data from very long baseline interferometry and satellite laser ranging combined with other geodetic and geologic data to study contemporary deformation in the Basin and Range province of the western United States. Northwest motion of the central Sierra Nevada block relative to stable North America, a measure of integrated Basin and Range deformation, is 12.1±1.2 mm/yr oriented N38°W±5° (one standard error), in agreement with previous geological estimates within uncertainties. This velocity reflects both east-west extension concentrated in the eastern Basin and Range and north-northwest directed right lateral shear concentrated in the western Basin and Range. …
Rapid Uplift And Rotation Of Mylonitic Rocks From Beneath A Detachment Fault: Insights From Potassium Feldspar 40ar/39ar Thermochronology, Northern Snake Range, Nevada, Jeffrey Lee
All Faculty Scholarship for the College of the Sciences
The thermal histories of mylonitic rocks from the footwall of the northern Snake Range decollement (NSRD), Nevada, were calculated using multiple diffusion domain analyses of potassium feldspar Arrhenius data and 40Ar/39Ar age spectra in order to characterize the cooling (exhumation) history of these mylonitic rocks and thereby constrain the origin and movement history of the NSRD. The calculated thermal histories, along with reported apatite fission track ages, indicate the three following episodes of rapid cooling (10–55°C/m.y.) related to extensional denudation: (1) middle Eocene (48–41 Ma), (2) late Oligocene (30–26 Ma), and (3) early Miocene (20–16 Ma). The …