Basin and Range

The Basin and Range Province is a particular type of topography that covers much of the southwestern United States and northwestern Mexico that is typified by elongate north-south trending arid valleys bounded by mountain ranges which also bound adjacent valleys. Death Valley is a good example of a modified basin and range valley.

Related Topics:
Topography - United States - Mexico - Valley - Mountain range - Death Valley

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The basins are down-fallen blocks of crust and the ranges are up-thrust slabs (actually the arrangement is a bit tilted to the east - in profile this would look similar to an encyclopedia leaning to one side - like so ///). The normal arrangement in the basin and range system is that each valley (i.e. basin) is bounded on each side by a normal fault that runs parallel to the range.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

This arrangement is very similar to the horsts and grabens seen in divergent plate boundaries such as the Mid-Atlantic Ridge or in failed rifting areas such as the Western Rift of the Great Rift Valley in East Africa. However the extent of the rifting in the Basin and Range is not concentrated into a single valley but is spread out over a very large area creating much smaller grabens laying roughly parallel to each other in a north-south direction (which leads to a rain shadow effect resulting in exceedingly dry conditions in this province).

Related Topics:
Horst - Graben - Divergent plate boundaries - Mid-Atlantic Ridge - Great Rift Valley - East Africa - Rain shadow

~ ~ ~ ~ ~ ~ ~ ~ ~ ~