with dikes of magma. Magma might move along, under the surface, breaking the rock and more importantly melting ice. The resulting action would cause a crack to form at the surface. Dikes caused both by tectonic stretching (extension) and by dikes are found in Iceland. Pit craters are not common on Earth. Sinkholes, where the ground falls into a hole (sometimes in the middle of a town) resemble pit craters on Mars. However, on the Earth these holes are caused by limestone being dissolved thereby causing a void. Knowledge of the locations and formation mechanisms of pit craters and fossae is important for the future colonization of Mars because they may be reservoirs of water. Tharsis quadrangle Arcadia quadrangle Elysium quadrangle Mare Tyrrhenum quadrangle Memnonia quadrangle Phoenicus Lacus quadrangle Diacria quadrangle Phaethontis quadrangle Ismenius Lacus quadrangle Cebrenia quadrangle Lunae Palus quadrangle Amenthes quadrangle References External resources Fossae on Mars Fossae on Venus Fossae on the Moon Fossae on Enceladus Fossae on Ganymede Surface features of bodies of the Solar System