HR: 0800h
AN: P21A-0203    [Abstracts]
TI: Hyperspectral Imaging of a Chemosynthetic Seep System in the Panoche Hills, California: A Possible Terrestrial Analog for Mixed Carbonate-Silicate Deposits on Mars
AU: * Schneider, E J
EM: ericas@es.ucsc.edu
AF: University of Californi Santa Cruz, Department of Earth Sciences 1156 High Street, Santa Cruz, CA 95064
AU: Moore, J C
EM: cmoore@es.ucsc.edu
AF: University of Californi Santa Cruz, Department of Earth Sciences 1156 High Street, Santa Cruz, CA 95064
AU: Schwartz, H
EM: hschwartz@es.ucsc.edu
AF: University of Californi Santa Cruz, Department of Earth Sciences 1156 High Street, Santa Cruz, CA 95064
AU: Silver, E
EM: esilver@es.ucsc.edu
AF: University of Californi Santa Cruz, Department of Earth Sciences 1156 High Street, Santa Cruz, CA 95064
AB: Chemosynthetic communities and carbonate substrate forming at cold seeps represent a unique ecosystem for studying life in extreme environments, such as Mars. Carbonate hardgrounds form due to the upward seepage of bicarbonate saturated fluid derived from methane oxidation. Carbonates can precipitate in the subsurface, resulting in high preservation potential. In the Panoche Hills of California, carbonate seep deposits contain fossilized chemosynthetic organisms and have negative carbon isotopic compositions, similar to other ancient cold seep deposits. The carbonates occur as mounds, concretions and pavements. The carbonate seep deposits of the Panoche Hills have been mapped in detail in the central portion of the field area and identified in the northern portion. These carbonates are well exposed, which make them good targets for remote sensing. Our remote sensing information is a 2 km by 8 km swath of HyMap hyperspectral data centered on the geologically well-mapped area. HyMap has 126 bands from visible to short wave infrared wavelengths (0.45 to 2.5 ŸYm). Carbonates have a diagnostic absorption feature at 2.34 ŸYm, within the range of HyMap­Ýs accuracy. Further, the carbonate seeps measure up to 10 meters across, and are detectable with HyMap­Ýs spatial resolution of 3-meter pixels. The methane derived carbonates of the Panoche Hills formed below the sediment-water interface and incorporated a significant amount of silicate minerals, complicating the spectral identification of carbonate. Spectra and GPS locations collected in the field provided data for comparison and helped to classify carbonates associated with siliciclastic material. A spectral library, based on field spectra, was used as input for classifying with ENVI remote sensing software. The successful inputs applied to the data set found potential unmapped carbonate localities as well as correct identification of previously mapped locations. Spectroscopic investigations on Mars suggest the presence of a small amount of dispersed carbonate minerals in the Martian dust and hematite concretions within sulfate deposits; carbonate formation probably followed sulfate development during evolution to the present atmospheric state. The remote detection of carbonate seeps at the Panoche Hills may serve as a terrestrial analog in the search for Martian carbonates.
DE: 5464 Remote sensing
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting