Elysium Quadrangle - Layers

Layers

Elysium Fossae contains layers, also called strata. Many places on Mars show rocks arranged in layers. Sometimes the layers are of different colors. Light-toned rocks on Mars have been associated with hydrated minerals like sulfates. The Mars Rover Opportunity examined such layers close-up with several instruments. Pictures taken from orbiting spacecraft show that some layers of rocks seem to break up into fine dust; consequently these rocks are probably composed of small particles. Other layers break up into large boulders, so they are probably much harder. Basalt, a volcanic rock, is thought comprise the layers that form boulders. Basalt has been identified on Mars in many places. Instruments on orbiting spacecraft have detected clay (also called phyllosilicates) in some layers. Scientists are excited about finding hydrated minerals such as sulfates and clays on Mars because they are usually formed in the presence of water. Places that contain clays and/or other hydrated minerals would be good places to look for evidence of life.

Rock can be formed into layers in a variety of ways. Volcanoes, wind, or water can produce layers.

• Layers in Monument Valley. These are accepted as being formed, at least in part, by water deposition. Since Mars contains similar layers, water remains as a major cause of layering on Mars.

• Angular Unconformity in Cerberus Fossae, as seen by HiRISE. Click on image to see the angles of the layers.

• Wrinkle Ridge and pit showing layers, as seen by HiRISE. Click on image to see layers. Scale bar is 500 meters long.

• Wide view of Iberus Vallis, as seen by HiRISE. Imagine taking a walk in these canyons and looking up at the layers.

• Detail from the center of the previous image, as seen by HiRISE.

• Layers around streamlined knob, as seen by HiRISE under HiWish program.