Variation in displacement along strike of the South Virgin–White Hills detachment fault: Perspective from the northern White Hills, northwestern Arizona

The Basin and Range Province as a Composite Extensional Domain

“…Farther east, the boundary is a more diffuse transfer zone that trends WNW-ESE, subparallel to the net vector of Neogene motion of the Sierra Nevada block with respect to the Colorado Plateau. This segment of the boundary, adjacent to the SECAL-SWAZ domain, is provisionally placed immediately south of a belt of prominent post-18 Ma or post-16 Ma extensional basins and intervening ranges, in northwesternmost Arizona and adjacent southernmost Nevada, extending as far to the southeast as the Hualapai Mountains (Faulds et al, 1988(Faulds et al, , 1990(Faulds et al, , 1997Deubendorfer and Simpson, 1994;Beard, 1996;Deubendorfer and Sharp, 1998;Faulds, 1999;Brady et al, 2000). The onset of major extension within this belt adjacent to the transtaphrogen bridge was delayed until after eruption of the Early Miocene Peach Springs Tuff at ~18.5 Ma (Dickinson, 1991;Stewart, 1998), and hence postdated much of the tectonic denudation within the Desert Southwest cluster of core complexes (Fig.…”

Thermochronology of the Salt Spring fault: Constraints on the evolution of the South Virgin–White Hills detachment system, Nevada and Arizona, USA

“…The 80-km-long SVWHD of southern Nevada and northern Arizona is an along-strike alignment of three west-dipping normal fault Reiners et al, 2000;Duebendorfer and Sharp, 1998;Karlstrom et al, 2010; this study (gray shading) Wasserburg and Lanphere, 1965 Apatite ssion-track Fitzgerald et al, 1991 andthis study (gray shading) Zircon ssion-track Bernet, 2009 Hornblende (H), biotite (B), and K-feldspar(K) 40 Ar/ 39 Ar Karlstrom et al, 2010 Duebendorfer and Sharp, 1998;Brady et al, 2000;Fitzgerald et al, 2009;Duebendorfer et al, 2010). Extension accommodated by the northern segment (the Lakeside Mine fault) exhumed an easttilted block of Proterozoic crystalline rocks at Gold Butte, Nevada Fryxell et al, 1992).…”

“…In this paper we refer to this tilted section as the northern White Hills block. The Salt Spring fault zone consists of brecciated crystalline footwall rocks, clay-rich fault gouge, and, locally, a microbreccia ledge (Duebendorfer and Sharp, 1998;Duebendorfer et al, 2010).…”

“…Multiple low-temperature thermochronology investigations have documented a period of rapid Middle Miocene cooling of the Gold Butte tilted block (Fitzgerald et al, 1991(Fitzgerald et al, , 2009Reiners et al, 2000Reiners et al, , 2002Bernet, 2009). The Lakeside Mine fault zone is characterized by chloritic breccia and mylonite with top-to-the-west shear sense (Fryxell et al, 1992;Duebendorfer and Sharp, 1998) and is estimated to have accommodated ~15 km of slip at an average slip rate of 8.6 ± 6 km/m.y. (Fitzgerald et al, 2009).…”

“…1 and 2). We focus on this fault because (1) it is part of the regionally important South Virgin-White Hills detachment system (SVWHD); (2) exhumation of the footwall of the SVWHD is well constrained by low-temperature thermochronology (Fitzgerald et al, 1991(Fitzgerald et al, , 2009Reiners et al, 2000Reiners et al, , 2002Bernet, 2009;Karlstrom et al, 2010); and (3) local exposures permit direct observation of the fault zone (Duebendorfer and Sharp, 1998;Howard, 2003;Howard et al, 2010). Our data come from the Salt Spring fault and the rocks immediately above and below it, and have implications for the regional pattern of exhumation along this detachment system.…”