diamictite

right|thumb|250px|Diamictite from Stolpe, eastern Germany thumb|250px|'Snowball Earth'-type diamictite from the Pocatello Formation, [[Idaho, United States]] thumb|250px|Boulder of diamictite of the Mineral Fork Formation, [[Antelope Island, Utah, United States]] thumb|Elatina Formation diamictite below Ediacaran GSSP site in the Flinders Ranges NP, South Australia. A$1 coin for scale.

Diamictite (; from Ancient Greek (): 'through' and (): 'mixed') is a type of lithified sedimentary rock that consists of unsorted to poorly sorted terrigenous sediment containing particles that range in size from clay to boulders, suspended in a matrix of mudstone or sandstone. The term was coined by Richard Foster Flint and others as a purely descriptive term, devoid of any reference to a particular origin. Some geologists restrict the usage to unsorted or poorly sorted conglomerate or breccia that consists of sparse, terrigenous gravel suspended in either a mud or sand matrix.