jccwrt
Ganges Mensa (false color) - Mars Reconnaissance Orbiter
Western Ganges Mensa, a 100 x 50 km wide plateau of layered sulfate-bearing deposits within the Ganges Chasma system. At its thickest, the Ganges Mensa deposits are nearly 4,000 m thick, almost the same elevation as the canyon rim. Deposits like this are common in the eastern regions of the Valles Marineris system. The source of these deposits is unclear. They may have been deposited in large lakes impounded within a closed canyons prior to the opening of the east end of Valles Marineris by catastrophic outflow floods. Alternatively, they may have been deposited by wind, or as ashfall deposits that were later altered by acidic groundwater.
Minerals are more easily identified in infrared light than with visible light. This false color image uses much of the near infrared spectrum to highlight differences in mineralogy. The brown/red color of sandy regions in this image indicate unaltered volcanic minerals, primarily olivine, which is typical for Martian sand. The pale yellow/green color of the lower layers may indicate the possible presence of clays, although these may be an artifact of bad color alignment in this image. The whitish/pale pink colors are typical of sulfate minerals, which are bland in the wavelengths of infrared light used to construct this image.
This image combines a 40 m/px false color CRISM hyperspectral image (2.53 micron, 1.51 micron, and 1.08 micron as RGB channels, respectively) with a 5 m/px monochrome CTX image. The CRISM image was collected on June 12, 2007, and the CTX image was collected on May 4, 2009.
Image Credit: NASA / JPL / MSSS / JHU / APL / Justin Cowart
Ganges Mensa (false color) - Mars Reconnaissance Orbiter
Western Ganges Mensa, a 100 x 50 km wide plateau of layered sulfate-bearing deposits within the Ganges Chasma system. At its thickest, the Ganges Mensa deposits are nearly 4,000 m thick, almost the same elevation as the canyon rim. Deposits like this are common in the eastern regions of the Valles Marineris system. The source of these deposits is unclear. They may have been deposited in large lakes impounded within a closed canyons prior to the opening of the east end of Valles Marineris by catastrophic outflow floods. Alternatively, they may have been deposited by wind, or as ashfall deposits that were later altered by acidic groundwater.
Minerals are more easily identified in infrared light than with visible light. This false color image uses much of the near infrared spectrum to highlight differences in mineralogy. The brown/red color of sandy regions in this image indicate unaltered volcanic minerals, primarily olivine, which is typical for Martian sand. The pale yellow/green color of the lower layers may indicate the possible presence of clays, although these may be an artifact of bad color alignment in this image. The whitish/pale pink colors are typical of sulfate minerals, which are bland in the wavelengths of infrared light used to construct this image.
This image combines a 40 m/px false color CRISM hyperspectral image (2.53 micron, 1.51 micron, and 1.08 micron as RGB channels, respectively) with a 5 m/px monochrome CTX image. The CRISM image was collected on June 12, 2007, and the CTX image was collected on May 4, 2009.
Image Credit: NASA / JPL / MSSS / JHU / APL / Justin Cowart