HR: 1340h
AN: P23A-0174    [Abstracts]
TI: Lack of Coastal Constructional Landforms on Mars: Implications for the Nature and State of Ancient Oceans in the Northern Lowlands
AU: * Ghatan, G J
EM: GhatanG@si.edu
AF: Smithsonian Institution, Center for Earth and Planetary Studies National Air and Space Museum, Washington, DC 20013-7012 United States
AU: Zimbelman, J R
EM: ZimbelmanJ@si.edu
AF: Smithsonian Institution, Center for Earth and Planetary Studies National Air and Space Museum, Washington, DC 20013-7012 United States
AB: Thermal Emission Imaging System (THEMIS) and Mars Orbiter Camera (MOC) images were used to regionally exam two globally mapped shorelines on Mars. All available THEMIS visible and MOC narrow angle images on or near the Arabia (previously contact 1) and Deuteronilus (previously contact 2) "shorelines" within the Chryse Planitia/Arabia Terra region and the Isidis Basin were systematically examined for the purpose of identifying any features that might reasonably be interpreted as coastal constructional landforms (e.g. barrier features, spits and tombolos) associated with the former presence of a standing body of water within the northern lowlands of Mars. Additionally, raw Mars Orbiter Laser Altimeter (MOLA) profiles were selected at intervals of ~75 - 100 km and examined across both shorelines in both study regions. These profiles were compared with Differential Global Positioning System profiles of paleo-shorelines on Earth from Spring Valley and Long Valley, Nevada in an effort to identify features characteristic of shorelines on Earth within the MOLA profiles across the previously identified Martian shorelines. To date, we find few, in any, convincing features within any of the THEMIS or MOC images within the Chryse/Arabia region or the Isidis Basin reasonably interpreted as coastal constructional landforms. Further, we find no convincing patterns within the MOLA profiles across the mapped shorelines indicative of coastal constructional landforms as they appear on Earth. The absence of such features does not preclude the existence of oceans or seas within the northern lowlands of Mars, but does place important constraints on the nature and state of any such standing bodies of water.
DE: 5415 Erosion and weathering
DE: 5419 Hydrology and fluvial processes
DE: 5465 Rings and dust
SC: Planetary Sciences [P]
MN: Fall Meeting 2005