Scree, or talus, is accumulation of broken rock fragments at the base of crags, mountain cliffs, or valley shoulders. Landforms associated with these materials are sometimes called scree slopes or talus piles. These deposits typically have a concave upwards form, while the maximum inclination of such deposits corresponds to the angle of repose of the mean debris size.
The term scree comes from the Old Norse term for landslide, skriða, while the term talus is a French word meaning a slope or embankment. The two terms are often used interchangeably, though scree commonly refers to smaller material like mixed gravel and loose dirt, talus to rocks larger than scree. Talus is usually the preferred term in scientific writing.