In planetary nomenclature, a chasma /ˈkæzmə/ (plural: chasmata /ˈkæzmətə/) is a deep, elongated, steep-sided depression.
The European Space Agency's Mars Express found evidence of perhaps epsomite and kieserite.
Some cliffs on Mars show a few darker layers standing out and often breaking into large pieces; these are thought to be hard volcanic rock instead of soft ash deposits.
Probably having been formed in water, sulfate deposits are of great interest to scientists because they may contain traces of ancient life.
Some suggest present or fossilized life forms may be found there because the deposits are relatively young.