Gorge Formation

Gorge formation is a geological process that occurs when a river or stream erodes the land around it, creating a deep, narrow valley with steep sides. Gorges can form over thousands of years due to the constant erosion caused by flowing water.

Three Gorges

One of the most famous examples of gorge formation is the Three Gorges on the Yangtze River in China. The Three Gorges, which include the Qutang Gorge, the Wuxia Gorge, and the Xiling Gorge, are believed to have formed no earlier than 10 million years ago. The formation of these gorges is attributed to the uplift of the Tibetan Plateau and the erosion caused by the Yangtze River.

Bedrock Erosion

Bedrock erosion is a critical factor in the formation of gorges. It occurs when the river's flow erodes the underlying rock, causing the bed of the river to lower and the sides of the river to steepen. This process can lead to the formation of steep-sided gorges.

Inner Gorges

Inner gorges, which are formed within a larger gorge, can also be created through the erosion process. The formation of inner gorges depends on the geometrical relationships between the river and the surrounding land.

Unexceptional Floods

Exceptional river gorge formation can occur even during unexceptional floods. This is because the erosion caused by floods can lead to the formation of amphitheatre-headed gorges, which are characterized by their steep, curved sides. These gorges can form over a relatively short period of time, as shown in a study where a ∼270-m long, ∼100-m deep, and ∼100–160-m wide canyon was carved over 6 years.

In conclusion, gorge formation is a natural geological process that occurs when a river or stream erodes the land around it, creating a deep, narrow valley with steep sides. This process can be influenced by factors such as bedrock erosion, inner gorge formation, and even unexceptional floods. The formation of gorges can take thousands of years and can be shaped by a variety of geological and environmental factors.