Pit Chain on the Eastern Flank of Pavonis Mons (Original NASA/MGS/MSSS b/w Frame)

Caption NASA originale:"Pavonis Mons is the middle of the 3 large Tharsis Montes Volcanoes in the Martian Western Hemisphere.
Located on the Equator at about 113° West Longitude, Pavonis Mons stands as much as 7 Km above the surrounding Plain. The MGS-MOC recently spied the above Chain of Elliptical Pits on the lower East Flank of Pavonis Mons. The picture covers an area approx. 3 Km wide by 3,4 Km in length. The Pits are aligned down the center of a 485 meters-(approx. 530 yards)-wide, shallow Trough.
The straight Trough and the Pits were both formed by collapse associated with faulting. The Scarp on each side of the Trough is a "Fault Line" - Troughs of this type are known to geologists as "Graben". Such features are typically formed when the ground is being moved apart by tectonic forces, or when the ground is uplifted by molten rock injected into the near sub-surface from deeper underground. Both processes may be contributing to the features seen on Pavonis Mons. The Pits follow the trend of these Faults, and indicate the locus of collapse".