Yardang

A yardang is a streamlined ridge carved from bedrock or other consolidated material by the combined action of wind driven sand and dust abrasion and deflation. Yardangs are typically three or more times longer than they are wide and, seen from above, resemble the hull of a boat, with a steep blunt face into the wind that tapers lower and narrower toward the lee end. They form where wind erodes a flat surface made of alternating harder and softer material, stripping away the soft rock and leaving the harder rock standing, so the resulting pattern reflects both the original rock layout and the airflow that shaped it.