What is a corrie, also known as a cirque?

A corrie, or cirque, is specifically defined as a hollow found on the side of a mountain that has been shaped by glacial erosion. This formation occurs as glaciers move through the landscape, carving out a bowl-like depression. The process leaves steep backwalls and often a flat bottom, which can sometimes accumulate a small lake called a tarn after the glacier melts.

In contrast to the other choices, which describe different geological formations and processes, a corrie is unique due to its association with glacial activity. Valleys formed by erosion can result from various types of erosion, not specifically glacial. A plateau is a flat elevated area of land that lacks the distinctive characteristics created by glaciers, and a volcanic crater refers to the depression that forms at the summit of a volcano following an eruption. Thus, only the description of a corrie captures the essence of this glacially formed feature.