Craters are most often the site of gully formation on Mars. Mega-gullies are also found on the southwestern parts of Vallis Marineris, and in this image from NASA 2001 Mars Odyssey spacecraft, on hills east of Argyre Planitia.
Craters are most often the site of gully formation on Mars. Mega-gullies are also found on the southwestern parts of Vallis Marineris, and in this image from NASA 2001 Mars Odyssey spacecraft, on hills east of Argyre Planitia.