HR: 0800h
AN: T51D-1372    [Abstracts]
TI: Geometry of Quaternary Fault Scarps in the East Potrillo Mountains, Dona Ana County, New Mexico
AU: * Cervera, S N
EM: sncervera@utep.edu
AF: University of Texas at El Paso, Department of Geological Sciences, El Paso, TX 79968
AU: Hurtado, J M
EM: hurtado@geo.utep.edu
AF: University of Texas at El Paso, Department of Geological Sciences, El Paso, TX 79968
AU: Andronicos, C L
EM: ca98@cornell.edu
AF: Cornell University, Department of Earth and Atmospheric Sciences, Snee Hall, Ithaca, NY 14850
AB: The East Potrillo Mountains are located just north of the Mexico-United States border in southwestern Dona Ana County, New Mexico, west of El Paso, Texas and southwest of Las Cruces, New Mexico. The structural features exposed in the East Potrillo Mountains formed in response to Laramide and Rio Grande Rift deformation and include middle Tertiary low-angle normal faults and late Tertiary high-angle normal faults. Along the range bounding faults are piedmont scarps that indicate continuous movement on the high-angle faults into the late Quaternary. The most dramatic of these is a north-striking fault scarp in the eastern foothills of the East Potrillo Mountains, a structure that may pose a major seismic hazard to El Paso and Las Cruces. Thus, the purpose of this study is to better understand the Quaternary deformation history of this structure using field and remote sensing observations. I will present measurements of the geometry of Quaternary deformation as constrained by displacements of geomorphic surfaces, including alluvial fans and fluvial deposits. To reproduce the fault scarp geometry, a number of profiles perpendicular to the scarp will be surveyed. From these profiles, estimations of fault scarp age will be made by using scarp-height-slope-angle relationships. The final outcome of this study will be an estimate of the average deformation rate on the fault and of when the last major earthquake occurred. These measurements are vital for constraining seismic hazards in the region.
DE: 8002 Continental neotectonics (8107)
DE: 8010 Fractures and faults
DE: 8036 Paleoseismology (7221)
DE: 8040 Remote sensing
DE: 8109 Continental tectonics: extensional (0905)
SC: Tectonophysics [T]
MN: Fall Meeting 2005