A steephead valley, steephead or blind valley is a deep, narrow, flat bottomed

valley A valley is an elongated low area often running between hills or mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over ...

with an abrupt ending. Such closed valleys may arise in

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms wh ...

or karst landscapes, where a layer of permeable rock lies above an impermeable substract such as marl. Water flowing through a steephead valley leaves via one or more ponors or

sinkhole A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. The term is sometimes used to refer to doline, enclosed depressions that are locally also known as ''vrtače'' and shakeholes, and to openi ...

s. Blind valleys are typically

dry Dry or dryness most often refers to: * Lack of rainfall, which may refer to ** Arid regions ** Drought * Dry or dry area, relating to legal prohibition of selling, serving, or imbibing alcoholic beverages * Dry humor, deadpan * Dryness (medica ...

at their lower ends. If the ponor cannot contain the high runoff during a flood event an intermittent flow may continue through the valley beyond the sink. Such a landform is called a semi-blind or half-blind valley.

Development

They are created by a stream flowing within the permeable rock and eroding it from within, until the rock above collapses opening up a steep narrow valley which is then further eroded by the stream running across the impermeable valley floor. At the head of the valley the stream emerges from the rock as a spring. Notable examples can be found in the Jura region of

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan ar ...

, for example the Reculée de Baume at Baume-les-Messieurs and the Reculée d'Arbois with its head at Les Planches-près-Arbois and its exit at

Arbois Arbois () is a commune in the Jura department, in the Bourgogne-Franche-Comté region, eastern France. The river Cuisance passes through the town, which centres on an arcaded central square where one can sample the local wines. The commune h ...

. In North America, blind valleys (the preferred American term) are found in the

Driftless Area The Driftless Area, a topographical and cultural region in the American Midwest, comprises southwestern Wisconsin, southeastern Minnesota, northeastern Iowa, and the extreme northwestern corner of Illinois. Never covered by ice during the last ...

and other karst regions.

Examples

* Tasghîmût * Gara Medouar

References

Canyons and gorges Geomorphology Valleys {{topography-stub

Development

Examples

See also

References