Clay minerals exposed by the wind between fields of crescent-shaped dunes on Mars
Clay minerals exposed by the wind between fields of crescent-shaped dunes on Mars
Today, wind is the main force driving changes to the landscape of Noachis Terra; more than 3.7 billion years ago, however, water is thought to have played that role. Surrounded by fields of crescent-shaped dunes are extensive areas of strikingly bright deposits. These are thought to be clay minerals that formed when the volcanic rocks of Noachis Terra came into contact with water. The wind has since eroded the covering of sand and dust, exposing these clay minerals.