High resolution THEMIS daytime infrared image mosaic of Noctis Labyrinthus and its surroundings. The area is crisscrossed by multiple sets of graben running in different directions. The shield volcano Pavonis Mons is at upper left.
Mariner 9 view of the Noctis Labyrinthus "labyrinth" at the western end of Valles Marineris on Mars. Linear graben, grooves, and crater chains dominate this region, along with a number of flat-topped mesas. The image is roughly 400 km across, centered at 6 S, 105 W, at the edge of the Tharsis bulge. North is up. Image located in Phoenicis Lacus quadrangle
Noctis Labyrinthus, "the labyrinth of the night", is a region of Mars between Valles Marineris and the Tharsis upland. It is located in the Phoenicis Lacus quadrangle. The region is notable for its maze-like system of deep, steep-walled valleys. The valleys and canyons of this region formed by faulting and many show classic features of grabens, with the upland plain surface preserved on the valley floor. In some places the valley floors are rougher, disturbed by landslides, and there are places where the land appears to have sunk down into pit-like formations. It is thought that this faulting was triggered by volcanic activity in the Tharsis region. Research described in December 2009 found a variety of minerals, including clays, sulfates, and hydrated silicas, in some of the layers.