Eos Chaos may be made of layer after layer of lava flows, probably mixed with deposits of volcanic ash that fell out of the air following big eruptions. It is likely the rock strata in the walls preserve a long geological history of Mars. Dark layers may be due to dark lava flows. The dark volcanic rock basalt is common on Mars. However, light-toned deposits may have resulted from rivers, lakes, volcanic ash, or wind blown deposits of sand or dust. The Mars Rovers found light-toned rocks to contain sulfates. Probably having been formed in water, sulfate deposits are of great interest
Little Lava Lake side of Little Lava Lake and leads south into Three Sisters Wilderness and on to Williamson Mountain. Little Lava Lake Little Lava Lake lies in the Cascade Range about west-southwest of Bend in the U.S. state of Oregon. A close neighbor of Lava Lake, from which it is separated by solidified lava, Little Lava Lake is at an elevation of in the Deschutes National Forest. Generally considered the source of the Deschutes River, the lake covers to an average depth of . Lava Lake, Little Lava Lake, and other nearby lakes formed after lava flows from Mount Bachelor altered drainage