RECENT FAULT SLIP IN QUEEN VALLEY, CALIFORNIA: IMPLICATIONS FOR FAULT KINEMATICS IN THE EASTERN CALIFORNIA SHEAR ZONE

The main purpose of this project is to investigate the late Pleistocene to Holocene fault slip history in Queen Valley, California, using field mapping and tectonic geomorphology, to understand better the kinematic evolution of recent faulting in the transition zone between dextral slip within the Eastern California Shear Zone and dextral slip within the Walker Lane Belt. Queen Valley is a ~16 km long, NE-trending basin bounded on the southeast by a NW-dipping range front normal fault at the north end of the White Mountains. Queen Valley is underlain by four major Pliocene(?) to Holocene alluvial fan surfaces. The oldest surface, Q1, is preserved as highly eroded, isolated remnants at the range front. The Q2 surfaces are preserved as large, relatively smooth surfaces within Queen Valley and abutting against the range front. Q3 surfaces, which have well-developed bar and swale topography, are the most dominant within the valley, and Q4 surfaces are present-day drainages. A ~1.7 km2 landslide at the southern end of the valley was deposited after formation of Q2, but prior to formation of Q3 surfaces. Our mapping has documented fault types and orientations that fall into four groups: (1) A series of NE-striking, NW- and SE-dipping normal fault scarps cut and offset Q1, Q2, and Q3 surfaces; (2) A set of NE-striking, left-lateral strike-slip faults, located on the northern side of the valley, cut Q2 surfaces; (3) Two NE-striking, right-lateral strike-slip faults cut Q2 and Q3 surfaces; and (4) A NW-striking right-lateral strike-slip fault, which merges into a EW-striking thrust fault, located at the southern end of the valley, cuts and offsets Q1, Q2, and Q3 surfaces. Topographic profiling of normal fault scarps yields a minimum net surface offset of 89.5 m and measurement of left-laterally and right-laterally deflected and offset channels yields net lateral offsets of 184 m and 43 m, respectively. Our mapping in Queen Valley indicates that transfer of dextral slip from the White Mountains-Owens Valley fault system is partitioned into four main components: NW-dipping normal slip, NE-striking left-lateral slip, NW-striking right-lateral slip, and EW-striking thrust slip.