Clastic rocks are a type of sedimentary rock formed from the accumulation and cementation of fragments, or clasts, of pre-existing rocks. These fragments can vary in size, ranging from tiny clay particles to large boulders. Common examples of clastic rocks include sandstone, shale, and conglomerate, each classified based on the size of the clasts they contain. The formation of clastic rocks typically occurs through processes like weathering, erosion, and deposition. Over time, sediments are compacted and cemented together by minerals, such as calcite or silica, which fill the spaces between the clasts. This process can take thousands to millions of years, resulting in the diverse range of clastic rocks found in nature.