A comprehensive textbook divided into six parts: clay minerals and weathering; clay sedimentation on land; origin and behaviour of clay minerals and associated minerals in transitional environments (estuaries, deltas) and shallow-sea environments; diverse origins of clay in the marine environment; post- sedimentary processes intervening during early and late diagenesis; use of clay stratigraphic data for the reconstruction of past climate, marine circulation, tectonics, and other paleogeographical aspects.