Basin and range is a geologic term for a type of topography characterized by a series of separate and parallel mountain ranges with broad valleys interposed, extending over a more or less wide area. It is typified by the topography found in the Great Basin in the western United States, which is part of a larger regional topography known as the Basin and Range Province. Basin and range provinces exist in other regions of the world as well, on dry land and also on the sea floor.

Basin and range topography results from crustal extension. As the crust stretches, faults develop to accommodate the extension. Most of these faults are vertically-oriented normal faults. The basins are down-fallen blocks of crust and the ranges are relatively uplifted blocks, many of which tilt slightly in one direction at their tops. The normal arrangement in the basin and range system is that each valley (i.e., basin) is bounded on each side by one or more normal faults that are oriented along or sub-parallel to the range front.

Basin and range faulting is characteristic of incipient rift zones in continental crust, and also of back-arc basins.

References

• Southern California Earthquake Data Center Glossary