The document discusses sedimentary rocks, which form through the lithification of sediments. Sediments are broken down into sizes from boulders to clay and are transported, deposited, and compacted in environments like beaches, rivers, lakes and oceans. Over time, sediments are cemented together by minerals like silica and calcite to form sedimentary rocks. The main types are clastic rocks like sandstone and conglomerate formed from fragments, and chemical rocks like limestone and halite formed from mineral precipitation. Biochemical rocks like coal also form from organic material. Sedimentary structures provide clues to depositional environments.