A scree slope formed of frost shattered rock debris which has fallen from the peaks above. A talus slope is usually straight, and at an angle of 34–35°. Slope angle in a talus cone reflects the balance between the supply of sediment from upslope (usually by physical weathering of bedrock) and the processes moving the sediment downslope while spreading it out. Lithology is also an important control. Grain flows are frequent occurrences; see Croasta et al. (2007) Geophys. Res. Abstr. 9, 07610 on grain size, and Pech and Kotarba (2002) Studia Geomorph. Carpatho-Balcanica 36, on talus slopes in the high Tatra. Obanawa and Matsukura (2006) Computers & Geosci. 32, 9 propose a mathematical model for the topographic change of a cross-section of a talus landform. See van Steijn et al. (2002) PPG 26, 4 on cliff-talus systems.

The slow, downslope movement of talus is talus creep, initiated either by the shock of new fragments falling on the scree or by the movement of individual particles resulting from heating and cooling.