Present-Day Deformation Across the Basin and Range Province, Western United States

Abstract

The distribution of deformation within the Basin and Range province was determined from 1992, 1996, and 1998 surveys of a dense, 800-kilometer-aperture, Global Positioning System network. Internal deformation generally follows the pattern of Holocene fault distribution and is concentrated near the western extremity of the province, with lesser amounts focused near the eastern boundary. Little net deformation occurs across the central 500 kilometers of the network in western Utah and eastern Nevada. Concentration of deformation adjacent to the rigid Sierra Nevada block indicates that external plate-driving forces play an important role in driving deformation, modulating the extensional stress field generated by internal buoyancy forces that are due to lateral density gradients and topography near the province boundaries.

Paleoseismic and Slip-Rate Observations along the Honey Lake Fault Zone, Northeastern California, USA

“…Our radiocarbon ages constrain the age of abandonment of the inset terrace surface to after 4670 calendar years B.P., yielding a minimum Holocene slip rate of 1:7 0:6 mm=yr. This slip rate is similar to that reported by Wills and Borchardt (1993) and is consistent with the Honey Lake fault accommodating a major portion of the 4-8 mm=yr of right-lateral shear (e.g., Thatcher et al, 1999) measured geodetically across the northern Walker Lane. The top of the terrace riser is interpreted to be within the 1267 and 1270.5 m contours on the west and east sides of the fault, respectively.…”

“…1). Geodetic observations indicate that about 6 2 mm=yr, or approximately 10%-15% of this relative motion, is accumulating across the northern Walker Lane (Thatcher et al, 1999;Thatcher, 2003). The Honey Lake fault zone comprises two main strands, a normal range-front fault (Russell, 1885) and a strike-slip strand Wills, 1990).…”

Mantle control of plate boundary deformation

“…Geodetic measurements indicate that current margin deformation occurs within a broad zone of strike-slip accommodation penetrating at least 400 Km into the continental interior, but the majority of shear strain occurs in close proximity to the surface expression of the continental margin (Figure 3; [Thatcher et al, 1999]. If the Pacific lithosphere constitutes a translating, impenetrable barrier to lower crustal flow which 'deflects' extending continental material northward, then mass balance requires that the mantle component of the young, subducting Gorda and Juan de Fuca plates must be substantially more penetrable than the impenetrable rheological step imaged here across the lower California transform system.…”

Late Pleistocene and Holocene Paleoearthquake Activity of the Olinghouse Fault Zone, Nevada

“…1) (Dokka and Travis, 1990;Savage et al, 1990;Thatcher et al, 1999;Bennett et al, 2003;Hammond and Thatcher, 2004). The Walker Lane is a zone of northwest-directed, right-lateral shear east of the Sierra Nevada and subparallel to the San Andreas fault zone ( Fig.…”