Turn this image sideways (so North is to the right) and the highstanding landforms look like an exclamation mark.

The origin of these hills may be difficult to understand on such ancient terrain. The straight edges suggest fractures related to faults. Maybe this feature was lifted up by the faulting, maybe the surrounding terrain has been eroded down over billions of years, or both.

Written by: Alfred McEwen   (12 January 2011)

More info and image formats at http://hirise.lpl.arizona.edu/ESP_020794_1860

Image: NASA/JPL/University of Arizona