A gap is a
geological formation that is a low point or opening between
hills or
mountain
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher ...
s or in a
ridge or
mountain range
A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have ari ...
. It may be called a
col, notch,
pass
Pass, PASS, The Pass or Passed may refer to:
Places
*Pass, County Meath, a townland in Ireland
* Pass, Poland, a village in Poland
* Pass, an alternate term for a number of straits: see List of straits
*Mountain pass, a lower place in a mounta ...
,
saddle
The saddle is a supportive structure for a rider of an animal, fastened to an animal's back by a girth. The most common type is equestrian. However, specialized saddles have been created for oxen, camels and other animals. It is not kno ...
,
water gap, or
wind gap, and
geomorphologically is most often carved by water erosion from a
freshet,
stream
A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long large streams ...
or a
river
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of ...
.
GNIS Feature Class Definitions: Gap
/ref> Gaps created by freshets are often, if not normally, devoid of water through much of the year, their streams being dependent upon the meltwaters of a snow pack. Gaps sourced by small springs will generally have a small stream excepting perhaps during the most arid parts of the year.
Water gaps of necessity often cut entirely through a barrier range and riverine gaps may create canyons such as the riverine gaps of the Danube River, Lehigh River Gorge, the Colorado River's Grand Canyon and the Genesee River. Such cuttings may expose millennia of strata in the local rock column writing the geologic record.
References
Landforms