Mars Global Surveyor
Mars Orbiter Camera

Layered and Massive Units, Candor Mensa

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


Not all martian sedimentary rocks are expressed as stacks of thin, repeated beds, all of similar thickness, like those in west Candor Chasma or western Arabia Terra; some of them consist of a single, thick layer with very little clear evidence for bedding (geologists use the term massive to describe such layers). On Mars, massive units are typically found above layered units, indicating that they are younger and that the depositional environment changed over time, from one that was changing in a repeated, episodic fashion, to one in which little change occurred over some period of time. This image, on the north slope of Candor Mensa in the Valles Marineris, shows a transition from layered lower units to a massive upper unit. The surface slopes down from the top to the bottom of the image, sunlight illuminates the scene from the lower right. The picture is a subframe of Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image M10-02361, obtained in December 1999. The north slope of Candor Mensa can be seen in a Viking orbiter image mosaic that is part of an accompanying release, "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.

To MSSS Home Page