The clay fraction of sediments drilled at Ocean Drilling Program (ODP) sites 1071 and 1072 is composed of variable proportions of chlorite, illite, smectite. kaolinite, vermiculite and mixed-layers such as illite/vermiculite (I/V) and chlorite/vermiculite (C/V). Miocene and Pliocene climates allowed formation of vermiculite and kaolinite. Pleistocene clay sedimentation was characterized by abundant chlorite and illite resulting from increasing erosion of the crystalline rocks outcropping in northern areas (e.g. Canadian Shield) developed under glacial climate. The clay minerals identified on the shelf are relatively similar to those deposited on the New Jersey continental slope and rise, and a similar trend in the composition of clay assemblages is... |