PIA09097: Layers Exposed at Polar Canyon January 6, 2007Posted by jtintle in Planets, Space Fotos.
Tags: Chasma Boreale, HiRISE, JPL-Caltech, Mars, Mars Reconnaissance Orbiter (MRO), NASA, Unversity of Arizona
NASA/JPL-Caltech/Univ. of Arizona
This false-color subframe of an image from the High Resolution Imaging Science Experiment camera on NASA’s Mars Reconnaissance Orbiter shows the north polar layered deposits at top and darker materials at bottom, exposed in a scarp at the head of Chasma Boreale, a large canyon eroded into the layered deposits.
The polar layered deposits appear red because of dust mixed within them, but are ice-rich as indicated by previous observations. Water ice in the layered deposits is probably responsible for the pattern of fractures seen near the top of the scarp. The darker material below the layered deposits may have been deposited as sand dunes, as indicated by the crossbedding (truncation of curved lines) seen near the middle of the scarp. It appears that brighter, ice-rich layers were deposited between the dark dunes in places. Exposures such as these are useful in understanding recent climate variations that are likely recorded in the polar layered deposits.