Mars Global Surveyor
Mars Orbiter Camera

Outcrops in Valles Marineris Walls

MGS MOC Release No. MOC2-265J, 4 December 2000


Outcrops of light-toned, layered sedimentary rock occurring in the walls of the Valles Marineris allows the age of these materials to be estimated. The Valles Marineris chasms are cut into flat, relatively un-cratered plains that have been estimated to have formed during a period in "middle" martian history generally thought to have been after 3.5 billion years ago. This means that any rocks that occur under these plains---such as the rocks exposed in the walls of the Valles Marineris---must come from the earliest part of martian history, which was between 4.5 billion (the age of the planets) and 3.5 billion years ago.

The example shown here includes two Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images taken in July 2000. On the left is a context image showing part of the northern wall of western Candor Chasma. The black box is 3 km (1.9 mi) wide and indicates the location of the picture on the right, a high resolution view of a portion of the chasm wall. The high resolution image shows light-toned layered rock coming out of the walls. The ridge in the upper left corner of the high resolution view is also composed of the same light-toned rock, but most of the ridge is covered by a veneer (perhaps less than 1 meter (1 yard)) thick) of dark debris. Sunlight illuminates these two pictures from the upper left, north is toward the upper right. For additional information about these outcrops, see "Light-toned Layered Outcrops in Valles Marineris Walls," MOC2-263, December 4, 2000.

Image Credit: NASA/JPL/Malin Space Science Systems

Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

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