Scree

Scree

Scree is a term used in geology and physical geography to describe an accumulation of loose, unconsolidated rock fragments that have collected at the base of a cliff, mountain, or slope due to weathering and erosion processes. These rock fragments can range in size from small pebbles to large boulders and are typically angular in shape, as they have not been subjected to the same level of erosion and transport as rounded river rocks. The formation of scree is often associated with frost weathering, where repeated freezing and thawing of water within rock crevices causes the rock to fracture and break apart. Scree can also be formed through other weathering processes, such as thermal expansion and contraction, salt crystallization, and biological weathering by plants. The accumulation of scree at the base of a slope can create a distinctive landform known as a scree slope or talus slope, which is characterized by a steep, unstable surface composed entirely of loose rock fragments. Scree slopes are common in mountainous regions and can pose challenges for hikers and climbers due to their instability and the potential for rockfall. In some cases, scree can also provide important habitat for certain plant and animal species that are adapted to these harsh, rocky environments.

talus, rockfall, weathering, erosion, slope

— John Armstrong