A deposit of angular composite stone fragments held together by a matrix of natural cement, such as sap, lime, or a calcium-charged water. Its occurrence indicates a previous cold phase in the climate, since the rock is detached either by frost or alternating heat and cold. Many caves occupied by early man, e.g. Dordogne in southwest France, have layers of breccia crammed with bones, tools, art objects. This conglomerate used by the ancient peoples in architecture and sculpture. It is the opposite of conglomerate, in which the fragments are rounded and waterworn. Osseous or bone breccia is breccia in which fossil bones are found.