The majority of the San Andreas fault zone is convergently oblique to relative plate motion. The commonness of transpression makes it significant for understanding deformation of the continental lithosphere. We have quantified the distribution of transpressional deformation along the San Andreas fault zone with respect to variations in boundary conditions along its length and distance from the fault zone itself. Rock uplift was used as a proxy for transpressional deformation. The pattern of exhumation along the fault was synthesized based on previously determined apatite fission-track and (U-Th)/He ages from 210 locations within 40 km of the fault trace. Patterns of mean elevation and slope in swaths along the fault were used as rough proxies of surface uplift and erosion. Relatively higher exhumation rates and mean elevations occur most commonly along the most oblique sections of the fault, such as in the Transverse Ranges. The highest rates of exhumation (>0.5 mm/yr) and highest and steepest topography also occur almost exclusively in the near field (i.e., within ∼10 km) of the fault trace. These trends are consistent with the strain-partitioning model of transpression, in which distributed deformation is concentrated in the fault zone and the degree of partitioning between simple and pure shear is a function of obliquity. However, the pattern of rock uplift also exhibits considerable variability. Neither the degree of obliquity nor the distance to the fault trace is enough to predict where high exhumation or mean elevation will occur. This suggests that heterogeneity in boundary conditions, including mechanical weaknesses and variations in erodibility, is equally important for controlling the pattern of transpressional deformation.

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Abstract Recent studies, including structural mapping, stratigraphic and sedimentologic studies, geothermochronology, and geodetic measurements, have improved our understanding of the kinematics of Miocene to Recent deformation in the central Basin and Range. Based on reconstructions of rocks in the extensionally dismembered foreland and leading edge of the Sevier thrust belt, offset along the Las Vegas Valley shear zone, and on the provenance of a unique clast assemblage in proximal channel facies deposits at Frenchman Mountain, the southern and northern Lake Mead extensional domains have extended ~94 km and ~46 km, respectively. A compilation of >70 cooling ages from the Gold Butte crystalline block indicates that onset of this extension occurred at ~20 Ma, with rapid, large-magnitude extension beginning at ~15 Ma. In the Death Valley extended domain, studies of the provenance, depositional environment, and age of the Eagle Mountain Formation show that middle Miocene siliciclastic strata occurring in a northwest-trending belt from Chicago Valley to the Cottonwood Mountains were all deposited in an environment proximal to the Hunter Mountain batholith of the Cottonwood Mountains. This requires ~100 km of roughly southeast-northwest extensional and strike-slip displacement since ~11 Ma. Identification of extensionally dismembered Cenozoic structures, correlative with structures in the Cottonwood Mountains, Panamint Range, Bare Mountain, the CP Hills, and the Funeral Mountains, are also consistent with ~100 km of west-northwest extension across the Death Valley region .