how are sedimentary rocks identified
Clastic sedimentary rocks contain clasts. These are fragments or pieces of rock or minerals. The composition of clastic sedimentary rocks is divided into three types-clay/silt, sand and gravel. Clay and silt are less than 1/16 mm. These are not visible to the unaided eye.lastic sedimentary rocks contain clasts. These are fragments or pieces of rock or minerals. The composition of clastic sedimentary rocks is divided into three types-clay/silt, sand and gravel. Clay and silt are less than 1/16 mm. These are not visible to the unaided eye.