Mineral and chemical compositions of clay sediments from the Pacific Ocean, DSDP data

Depending on evolution of the region two ways of clay sediment formation are identified: terrigenous and authigenic. It is shown that terrigenous clay sediments predominate in marginal parts of the Pacific Ocean.

Authigenic mineral formation occurring in the basal part of the sedimentary cover primarily results from removal of material from underlying basalts. This material is released during secondary alteration of the basalts due to their interaction with sea water, as well as with deep solutions.