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JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 108, NO. E12, 8073, doi:10.1029/2002JE001982, 2003

Mantled and exhumed terrains in Terra Meridiani, Mars

R. E. Arvidson

McDonnell Center for the Space Sciences, Department of Earth and Planetary Sciences, Washington University, St. Louis, Missouri, USA


F. P. Seelos IV

McDonnell Center for the Space Sciences, Department of Earth and Planetary Sciences, Washington University, St. Louis, Missouri, USA


K. S. Deal

McDonnell Center for the Space Sciences, Department of Earth and Planetary Sciences, Washington University, St. Louis, Missouri, USA


W. C. Koeppen

McDonnell Center for the Space Sciences, Department of Earth and Planetary Sciences, Washington University, St. Louis, Missouri, USA


N. O. Snider

McDonnell Center for the Space Sciences, Department of Earth and Planetary Sciences, Washington University, St. Louis, Missouri, USA


J. M. Kieniewicz

McDonnell Center for the Space Sciences, Department of Earth and Planetary Sciences, Washington University, St. Louis, Missouri, USA


B. M. Hynek

McDonnell Center for the Space Sciences, Department of Earth and Planetary Sciences, Washington University, St. Louis, Missouri, USA


M. T. Mellon

Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado, USA


J. B. Garvin

NASA Goddard Space Flight Center, Greenbelt, Maryland, USA


Abstract

Hematite-bearing deposits in the Terra Meridiani region of Mars constitute the top stratum of a partially eroded layered complex that covers dissected Noachian-aged cratered terrain. The hematite unit consists of dark plains and dunes covering a bright substrate. This substrate is fully exposed beyond the borders of the hematite-bearing deposit and consists of polygonal ground separated by ridges or valleys, together with layered deposits that have been eroded into a variety of landforms. The complex is partially covered by a regional-scale aeolian mantle that thickens toward the north. The hematite-bearing stratum exhibits low albedoes, pulse widths, and intermediate thermal inertias, whereas the underlying unit exhibits high values of these parameters. Both units have spectral emissivity signatures similar to those for the low albedo cratered terrain to the south, with the addition of hematite for the top stratum. The complex is interpreted to consist of extensive plains-forming lava flows and tephra deposits emplaced during an extensional regime and at least partially buried by an aeolian mantle. Aeolian stripping of the mantle exposed much of the complex and differentially eroded the deposits to produce the landforms existent today. Exploration of the hematite-bearing deposits by the 2003 Mars Exploration Rover, “Opportunity,” will allow testing of the hypotheses presented since this stratum has been locally reworked into dunes that only partially cover the underlying brighter portion of the complex. In particular, the rover-based measurements will allow us to test the extent to which the unusual remote-sensing properties of the units indicate aqueous alteration.

Received 9 December 2002; accepted 22 December 2002; published 18 October 2003.

Index Terms: 6225 Planetology: Solar System Objects: Mars; 5470 Planetology: Solid Surface Planets: Surface materials and properties; 5464 Planetology: Solid Surface Planets: Remote sensing; 5415 Planetology: Solid Surface Planets: Erosion and weathering.

Read Full Article (file size: 4626512 bytes)    Cited by

Citation: Arvidson, R. E., F. P. Seelos IV, K. S. Deal, W. C. Koeppen, N. O. Snider, J. M. Kieniewicz, B. M. Hynek, M. T. Mellon, and J. B. Garvin (2003), Mantled and exhumed terrains in Terra Meridiani, Mars, J. Geophys. Res., 108(E12), 8073, doi:10.1029/2002JE001982.