Clastic rock rich in lithics are called lithic sandstones. Siliciclastic sedimentary rocks are composed of mainly silicate particles derived by the weathering of older rocks and pyroclastic volcanism. While grain size, clast and cementing material (matrix) composition, and texture are important factors when regarding composition, siliciclastic sedimentary rocks are classified according to grain size into three major categories; conglomerates, sandstones, and mudrocks. The term clay is used to classify particles smaller than .0039 millimeters. However, term can also be used to refer to a family of sheet silicate minerals. Silt refers to particles that have a diameter between .062 and .0039 millimeters.
Parramatta Sand Body Conservation Area and Military Barracks Site and slightly mottled with depth. The upper parts of the soil profile are usually heavily mixed, especially by cicada larvae. In places the sand is cut by deposits of mottled or gleyed clay that were probably deposited in swamps or waterholes on the terrace surface. The reasonably defined levee, 50 to 100 centimetres high, along the terrace edge between Charles and Alfred Streets, comprises cleaner and very slightly coarser sand than the sand found around the margins of the levee. The profile of the sand suggests that the main body of sand is of late Pleistocene age and recent thermoluminesence