In this VIS image, taken by the NASA - Mars Odyssey Orbiter on September, 8th, 2014, and during its 56.489th orbit around the Red Planet, we can see that the small section of the (almost) Linear Depression located in lower portion of the image, is a Graben (---> such as a Fault-bounded Block of Material). This Graben is called Mangala Fossa.
The morphology of the Mangala Fossa Graben, forming the source of the Mangala Valles, implies that - at least - two episodes of Graben Subsidence took place, each induced by Lateral Dike Intrusion from the Giant Martian Volcano known as Arsia Mons.
Latitude (centered): 20,1391° South
Longitude (centered): 205,1860° East
This image (which is an Original Mars Odyssey Orbiter b/w and Map-Projected frame published on the NASA - Planetary Photojournal with the ID n. PIA 18757) has been additionally processed, magnified to aid the visibility of the details, contrast enhanced and sharpened, Gamma corrected and then colorized in Absolute Natural Colors (such as the colors that a normal human eye would actually perceive if someone were onboard the NASA - Mars Odyssey Orbiter and then looked down, towards the Surface of Mars), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team.