MAPPING PLEISTOCENE-AGE SHORELINE DEPOSITS IN THE SEISMICALLY-ACTIVE SALTON TROUGH USING THERMAL INFRARED MULTISPECTRAL SCANNER (TIMS) DATA

The Salton Trough region of southern California is one of the most tec tonically active regions in North America. Pleistocene-age shoreline d eposits of the ancient Lake Cahuilla have been documented at various l ocations throughout the Salton Trough and potentially across several a ctive faults. Extensive mapping of the shoreline deposits would allow their use as time-stratigraphic horizons and precise elevational surve ying would permit characterization of vertical deformation, and provid e information on displacement and slip rates. Imagery from the NASA/JP L airborne Thermal Infrared Multi-spectral Scanner (TIMS) and held rad iometric data were evaluated for their applicability to mapping the Pl eistocene-age shoreline deposits. Differences in the textural and mine ralogical properties of shoreline deposits relative to the surrounding lacustrine and alluvial sediments were exploited. The results show th at when compared with field-derived maps of known shoreline deposits, digitally enhanced TIMS imagery enabled reliable delineation of the sh oreline deposits.