Sedimentology on Mars as
Seen by HiRISE
Bridges, Nathan1, HiRISE Team2 (1) Jet Propulsion Laboratory,
The High Resolution Imaging Science
Experiment (HiRISE) camera on the Mars Reconnaissance
Orbiter (MRO) will provide the highest resolution orbital images ever of the
Martian surface. With a ground sampling distance of 30 cm per pixel, it will
resolve meter-scale features. Having a wide field of view (6 by up to 20+ km),
high signal-to-noise, and high geometric precision, HiRISE
images should answer key questions central to Martian geology. As of this
writing, HiRISE has acquired 8 images of Mars, taken
right after orbital insertion at an altitude ~2500 km. Even at this resolution
(~2.5 m/pixel), megaripples, gullies, channels, and
possible glacial features are seen. By the time this abstract is presented,
hundreds of HiRISE images at full resolution should
be available. These should provide fundamental insight into many Martian sedimentological problems, including: - The origin of
bedrock units as revealed in the characteristics of exposed layering at the
decimeter scale. Stereo data will quantify layer thickness and absolute height,
thereby helping determine if layers follow specific elevations and therefore
likely formed in a lacustrine environment.
Large-scale depositional structures such as cross-bedding and faults and
associated fluid flow may also be resolvable. - The origin of fluvial
landforms, including the enigmatic young Martian gullies. - Determining if any
dune or megaripple migration occurs at meter scales
over the 3+ year duration of MRO. - Assessment of the distribution, form, and morphometry of yardangs. - The
rates and characteristics of landscape modification from aeolian
and fluvial processes.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California