HR: 0800h
AN: P21B-0142    [Abstracts]
TI: Geomorphic and Spectral Mapping of Meridiani Planum Northern Etched Terrains
AU: * Griffes, J L
EM: jgriffes@wustl.edu
AF: Washington University, Dept. of Earth and Planetary Sciences, Campus Box 1169, One Brookings Drive, Saint Louis, MO 63130 United States
AU: Arvidson, R E
EM: arvidson@rsmail.wustl.edu
AF: Washington University, Dept. of Earth and Planetary Sciences, Campus Box 1169, One Brookings Drive, Saint Louis, MO 63130 United States
AU: Poulet, F
EM: francois.poulet@ias.u-psud.fr
AF: Institut d'Astrophysique Spatiale, Université Paris-Sud, Orsay Cedex, 91405 France
AU: Bibring, J
EM: bibring@ias.fr
AF: Institut d'Astrophysique Spatiale, Université Paris-Sud, Orsay Cedex, 91405 France
AB: Mars Orbiter Camera (MOC), Mars Orbiter Laser Altimeter (MOLA), Thermal Emission Imaging System (THEMIS), and Mars Express (OMEGA) data were compiled and coregistered for analysis of a several hundred meter vertical section of etched terrain materials in the northern portion of Meridiani Planum. Seven units were mapped in the study area (-2.25°E to 0.75°E, 0.25°N to 4°N) based on geomorphology and distinct spectral signatures in OMEGA hyperspectral data (C-spectrometer, 0.9263 to 2.6949 μ m) acquired during orbit 485. The base of the stratigraphic column is occupied by cratered plains materials that exhibit low albedo and spectral signatures dominated by pyroxene. This unit is disconformably overlain to the south by etched terrain materials characterized by widely distributed knobby and mesa-like surfaces. Etched terrain materials show absorption bands at 1.92, 2.10 and 2.40 μ m, consistent with the presence of kieserite (Arvidson et al, 2005, Science). The third unit is topographically and stratigraphically higher than the second unit, also characterized by bumpy and mesa-like terrain, and shows spectral evidence for kieserite. The fourth unit is bright and has a strong 1.92 μ m band, indicative of the presence of water hydration. This unit is extensively exposed just to the north of the hematite-bearing plains defined by Christensen et al, 2001, JGR. The fifth unit is the hematite-bearing plains, extensively exposed in the southern portion of the study area. Finally, the uppermost unit consists of partially dissected mantled terrain, well exposed in the eastern-most section of the study area. This unit has spectral reflectance properties consistent with bright dust and is interpreted as a wind-blown deposit superimposed on etched terrain materials. The geomorphology, spectral properties and stratigraphy indicate that extensive aeolian erosion has exposed a well-defined sequence of sedimentary units deposited over the Noachian cratered terrain.
DE: 5410 Composition (1060, 3672)
DE: 5415 Erosion and weathering
DE: 5464 Remote sensing
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: Fall Meeting 2005