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AN odd, previously unseen landform could provide a window into the geological history of Mars, according to new research by University of Washington, United States, geologists. They call the structures periodic bedrock ridges. The ridges look like sand dunes but, rather than being made from material piled up by the wind, the scientists say the ridges actually form from wind erosion of bedrock.
“These bedforms look for all the world like sand dunes but they are carved into hard rock by wind,” said David Montgomery, a UW professor of Earth and Space sciences. It is something there are not many analogs for on Earth.”
He believes the ridges, while still bedrock, are composed of a softer, more erodible material than typical bedrock and were formed by an unusual form of wind erosion that occurs perpendicular to the prevailing wind rather than in the same direction.
He contrasts the ridges with another bedrock form called a yardang, which has been carved over time by headwinds. A yardang has a wide, blunt leading edge in the face of the wind, and its sides are tapered so that it resembles a teardrop.
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