https://ntrs.nasa.gov/search.jsp?R=20080041011 2019-08-29T19:11:15+00:00Z View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by NASA Technical Reports Server RECENT GEOLOGIC MAPPING RESULTS FOR THE POLAR REGIONS OF MARS. K.L. Tanaka1 and E.J. Kolb2, 1Astrogeology Team, U.S. Geological Survey, Flagstaff, AZ 86001,
[email protected], 2Google, Inc., Mountain View, CA 94043,
[email protected]. Introduction: The polar regions of Mars include the steep scarps exposed on the margins of Abalos Mensa, densest data coverage for the planet because of the polar from Boreum and Tenuis Cavi at the head of Chasma orbits of MGS, ODY, and MEX. Because the geology of Boreale, and from reentrants of Olympia Cavi into the polar plateaus has been among the most dynamic on Planum Boreum. The bases of the scarps include dark, the planet in recent geologic time, the data enable the cross-bedded bright and dark layered material mapped most detailed and complex geologic investigations of any as the Planum Boreum cavi unit (ABbc) [7, 10]. Some regions on Mars, superseding previous, even recent, map- of the dunes of Olympia Undae are embayed by the ping efforts [e.g., 1-3]. Geologic mapping at regional and young mid-latitude mantle [11] and the youngest polar local scales is revealing that the stratigraphy and modifi- layered deposits (Planum Boreum unit 2). cational histories of polar materials by various processes The Planum Boreum cavi unit grades upwards into are highly complex at both poles. Here, we describe some Planum Boreum 1 unit (ABb1), which forms the major- of our recent results in polar geologic mapping and how ity of what are commonly referred to as “polar layered they address the geologic processes involved and implica- deposits” (however, other polar deposits are also lay- tions for polar climate history.