A type of geological structure where a rock layer has pushed up into the rock layer above in a typically spherical shape. Domes are often good oil or gas traps

A domical arch (anticline) of sedimentary rock beneath the earth’s surface in which the layers bend downward in opposite directions from the crest and that has a mass of rock salt as its core. Salt is a peculiar substance. If you put enough heat and pressure on it, the salt will slowly flow, much like a glacier that slowly but continually moves downhill. Unlike glaciers, salt which is buried kilometers below the surface of the Earth can move upward until it breaks through to the Earth’s surface, where it is then dissolved by ground- and rain-water. To get all the way to the Earth’s surface, salt has to push aside and break through many layers of rock in its path. This is what ultimately will create the oil trap. Hydrocarbons are commonly found around salt domes because of the abundance and variety of traps created by salt movement and the association with evaporite minerals that can provide excellent sealing capabilities