how do biochemical sedimentary rocks form
Sedimentary rocks can be subdivided in three categories: clastic, chemical, and biochemical sedimentary rocks. A. CLASTIC (or DETRITAL) SEDIMENTARY ROCKS Clastic sedimentary rocks form when individual grains (the sediment), made by fragments of rocks, minerals, or shells, are cemented together (the clastic sediemntary rock). These are the only type of rock that is NOT made simply of crystals, but rather fragments of other materials, broken and then reassembled together.