In this VIS image, taken by the NASA - Mars Odyssey Orbiter on April, 16th, 2014, and during its 54.733rd orbit around the Red Planet, we can see, on the left (Sx) lower side of the frame, a "Linear Depression" which is called, in Planetary Science, "Graben". In fact, the Graben, in general terms, are Surface Depressions (in a way, VERY similar, sometimes, to Channels and Valleys), that are bounded (---> limited), on both sides, by Faults; the compact - and extremely smooth - Material that is located at their centre has shifted downward between the Faults themselves, due to either Seismic or even (but more rarely) Tectonic Activities.
Cyane Fossae, which is the location of the Graben visible in today's APOD, is a Region located near the large Martian Shield Volcano known as Alba Mons. On the very top of the frame, there is another - very well visible - visible Surface Depression but, in that case, we, as IPF, believe that it is NOT a Graben, but rather a Volcanic Fissure (---> relatively narrow and steep-walled canyon) or the final portion of a Collapse Feature. As usual, like we know it happens in this Region of Mars, only a few (and small) Impact Craters can be seen on the imaged Surface.
Latitude (centered): 28,9208° North
Longitude (centered): 245,0570° 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 18499) 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 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.