Mars Global Surveyor
Mars Orbiter Camera

Unconformity in Gale Crater Mound

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


A hint as to the complexity of the history recorded in the rocks of the Gale Crate central mound is shown by the partial emergence of a buried crater from beneath a light-toned, massive (i.e., not layered) rock unit. The massive light-toned rock covers the upper left quarter of the image on the left, which is a subframe of Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image M03-01521. The picture on the right is a colored map showing the different layered and massive rock units identified in the Gale Crater mound; the white box indicates the location of the picture on the left. The crater seen here formed in a previously-existing layered rock unit that was later buried by the light-toned massive unit seen at the upper left. This means that there is a gap in the geologic record---some of the history of this location is missing---because the gray-toned rock into which the crater formed was exposed to the atmosphere and eroded and hit by meteorites (to form craters) before the light-toned massive material was deposited and the record resumed. In geologic terms, this kind of relationship is called an unconformity. Refer to "Oblique view of Gale Crater Mound," MOC2-265E, December 4, 2000 to see the location of the color map relative to the entire mound. For additional information about Gale Crater, see Sediment History Preserved in Gale Crater Central Mound, MOC2-260, 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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