An asymmetric valley is a

valley A valley is an elongated low area often running between Hill, hills or Mountain, 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 ...

that has steeper

slope In mathematics, the slope or gradient of a line is a number that describes both the ''direction'' and the ''steepness'' of the line. Slope is often denoted by the letter ''m''; there is no clear answer to the question why the letter ''m'' is use ...

s on one side. Asymmetric valleys are

azonal In geography, azonal is an adjective that refers to processes or things that are not restricted to any climate zone. It can be used to describe soils, landforms, geomorphic processes or vegetation. Volcanism and mountain-related processes are exampl ...

landforms. In high altitudes south-facing slopes are usually steeper than north-facing slopes. Large incised rivers crossing

strike-slip fault In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

s can form asymmetrical valleys, as one bank of the river might be continuously being renewed while the other bank drifts away from the stationary river. A smaller river does not develop an asymmetrical valley as the whole river is offset or bent by the fault, rather than the river modifying the moving tectonic block. An example of this kind of asymmetrical valley can be found at the crossing of the

Yellow River The Yellow River or Huang He (Chinese: , Standard Beijing Mandarin, Mandarin: ''Huáng hé'' ) is the second-longest river in China, after the Yangtze River, and the List of rivers by length, sixth-longest river system in the world at th ...

with the Zhongwei-Tongxin fault.

References

{{geomorphology-stub Tectonics Valleys