[meteorite-list] MRO Reveals Rock Fracture Plumbing On Mars

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu, 25 Sep 2008 12:54:27 -0700 (PDT)
Message-ID: <200809251954.MAA13145_at_zagami.jpl.nasa.gov>

Sept. 25, 2008

Dwayne Brown
Headquarters, Washington
202-358-1726
dwayne.c.brown at nasa.gov

Guy Webster
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6278
guy.webster at jpl.nasa.gov

Lori Stiles
University of Arizona, Tucson
520-626-4402
lstiles at u.arizona.edu

RELEASE: 08-244

NASA ORBITER REVEALS ROCK FRACTURE PLUMBING ON MARS

PASADENA, Calif. -- NASA's Mars Reconnaissance Orbiter has revealed
hundreds of small fractures exposed on the Martian surface that
billions of years ago directed flows of water through underground
Martian sandstone.

Researchers used images from the spacecraft's High Resolution Imaging
Science Experiment, or HiRISE, camera. Images of layered rock
deposits at equatorial Martian sites show the clusters of fractures
to be a type called deformation bands, caused by stresses below the
surface in granular or porous bedrock.

"Groundwater often flows along fractures such as these, and knowing
that these are deformation bands helps us understand how the
underground plumbing may have worked within these layered deposits,"
said Chris Okubo of the U.S. Geological Survey in Flagstaff, Ariz.

Visible effects of water on the color and texture of rock along the
fractures provide evidence that groundwater flowed extensively along
the fractures.

"These structures are important sites for future exploration and
investigations into the geological history of water and water-related
processes on Mars," Okubo and co-authors state in a report published
online this month in the Geological Society of America Bulletin.

Deformation band clusters in Utah sandstones, as on Mars, are a few
yards wide and up to a few miles long. They form from either
compression or stretching of underground layers, and can be
precursors to faults. The ones visible at the surface have become
exposed as overlying layers erode away. Deformation bands and faults
can strongly influence the movement of groundwater on Earth and
appear to have been similarly important on Mars, according to this
study.

"This study provides a picture of not just surface water erosion but
true groundwater effects widely distributed over the planet," said
Suzanne Smrekar, deputy project scientist for the Mars Reconnaissance
Orbiter at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
"Ground water movement has important implications for how the
temperature and chemistry of the crust have changed over time, which
in turn affects the potential for habitats for past life."

The recent study focuses on layered deposits in Mars' Capen crater,
approximately 43 miles in diameter and 7 degrees north of the
equator. This formerly unnamed crater became notable due to this
discovery of deformation bands within it and was recently assigned a
formal name. The crater was named for the late Charles Capen, who
studied Mars and other objects as an astronomer at JPL's Table
Mountain Observatory in southern California and at Lowell
Observatory, Flagstaff, Ariz.

The HiRISE camera is one of six science instruments on the orbiter. It
can reveal smaller details on the surface than any previous camera to
orbit Mars. The orbiter reached Mars in March 2006 and has returned
more data than all other current and past missions to Mars combined.

The mission is managed by JPL for NASA's Science Mission Directorate.
Lockheed Martin Space Systems of Denver built the spacecraft. The
University of Arizona operates the HiRISE camera, built by Ball
Aerospace and Technology Corp. of Boulder, Colo.

Images of the deformation band clusters and additional information
about the mission are on the Internet at:



http://www.nasa.gov/mro


For more information about NASA and agency programs, visit:



http://www.nasa.gov

        
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Received on Thu 25 Sep 2008 03:54:27 PM PDT