In physical geography and geology, a horst is the raised fault block bounded by normal faults. The raised block is a portion of the Earth's crust that has remained stationary while the land has sunk on either side of it or has been crushed by a mountain range against it.

The Vosges and Black Forest are examples of the former, the Table, Jura and the Dôle mountains are results of the latter. The word is also applied to those larger areas, such as the Russian plain, Arabia, India and Central South Africa, where the continent remains stable, with horizontal table-land stratification, in distinction to folded regions such as the Eurasian chains.

"Horst" is the German word for aerie, the nest of a bird (such as an eagle) that is located on a high place such as a cliff.

See also

• Graben