Wednesday, August 4, 2010

Layered Rocks in a Crater in Arabia Terra

This image shows a ground surface composed of many thin light– and dark–toned layers.

These layers are mostly parallel with adjacent layers, and sets of layers often form intricate curved shapes that are reminiscent of wood grain.

What we see here is actually a series of rock layers that have been sequentially laid down on the floor of a large impact crater. These layers create interesting geometric patterns because they initially accumulated as large ripples, or sand dunes.

Subsequently, the ground surface was eroded away by the wind, revealing these underground layers of bedrock.

Photo credit: NASA/JPL/University of Arizona

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