Clastics
Clastics, in geology, refers to clastic sedimentary rocks or sediments formed from clasts—fragments of preexisting rocks or minerals that have been produced by weathering, transported, deposited, and lithified. They are contrasted with chemical sedimentary rocks, formed by precipitation from solution, and organic (biochemical) rocks, formed from accumulated biological matter.
The essential feature of clastics is the presence of discrete fragments. Clasts range in size from boulders
Formation involves several stages: weathering to create clasts, erosion and transport to move them, deposition of
Clastic rocks are commonly classified by clast size and rock texture. Gravel-sized clastics include conglomerate (rounded
Depositional environments for clastics are diverse, ranging from high-energy rivers and alluvial fans to deserts (aeolian