Meridiani Planum (Mars)

This feature is named after an earlier feature.

Meridiani Planum is a plain located 2 degrees south of Mars' equator in the westernmost portion of Terra Meridiani. It hosts a rare occurrence of gray crystalline hematite. On Earth, hematite is often formed in hot springs or in standing pools of water; therefore, many scientists believe that the hematite at Meridiani Planum may be indicative of ancient hot springs or that the environment contained liquid water. The hematite is part of a layered sedimentary rock formation about 200 to 800 meters thick. (wikipedia entry)

A planum is a plateau or high plain. On Mars they are named after the nearest named albedo feature on the Schiaparelli or Antoniadi maps.