The Mangala Valles are a complex system of criss-crossing channels on Mars, located in the Tharsis region and in the Memnonia quadrangle.

They are thought to be an outflow channel system, carved by catastrophic floods, and the release of vast quantities of water across the Martian surface.

This flooding was probably initiated by tectonic stretching and the formation of a graben, Mangala Fossa, at the channels' head, perhaps breaching a pressurized aquifer trapped beneath a thick "cryosphere" (layer of frozen ground) beneath the surface.

[12] The presence of scoured bedrock at the base of the mapped stratigraphy, together with evidence from crater retention ages, suggests that fluvial activity came before lava flows.

These alternating periods of aqueous flooding and volcanism are similar to that of other outflow systems on Mars, such as Ravi Vallis and the Kasei Valles.