It cuts through layered deposits that are thought to be sediments from an old lake that resulted from runoff of the valley networks to the west.

[1] Support for abundant, past water in Melas Chasma is the discovery by MRO of hydrated sulfates.

The floor of Melas Chasma is about 70% younger massive material that is thought to be volcanic ash whipped up by the wind into eolian features.

[4] In a recent study of southwestern Melas Chasma using high-resolution image, topographic and spectral datasets eleven fan-shaped landforms were found.

These fans add to growing evidence that Melas Chasma once held a lake that had fluctuating levels.