(a) Lateral movements in a fractured mass of rock or soil, which result from liquefaction or plastic flow of subjacent materials. (b) Lateral movement of intact blocks of soil or rock material which slide on a gently inclined planar surface, such as a bedding plane or a liquefied sand layer.
(Neuendorf, K.K.E. and others, 2005)
DGGS online catalog of government agency publications relating to: Lateral spread