True colour plan view of the western part of Arda Valles
True colour plan view of the western part of Arda Valles
This view of Arda Valles and its surroundings shows a diverse landscape, shaped by various geological processes. Particularly striking is the branching network of small valleys shown in the left half of the image, which is characteristic of the run-off of surface water. On the surface of Mars, such ‘dendritic’ run-off systems, like the branches of a tree, were principally formed in the planet’s early days. If one zooms into the high-resolution image, light layered deposits can be seen, formed by clay minerals. These are also characteristic of the early period of Mars, during which the minerals in volcanic rock were converted into clay minerals by contact with water.
At the top centre of the image, there is a 2000-metre-high mountain range, from which sediments were borne into the surroundings. These were also then deposited in craters. In the right half of the image, the southwest portion of an enormous, unnamed impact basin can be seen. This basin is also filled with sediments; tectonic faults were the result of settlement movements.
