The relationships between mineralogical and geochemical data on the three successive sedimentary facies at Deep Sea Drilling Project Site 464 are studied. The evolution of siliceous biogenic sediments is derived from the analyses of one Fe-Ti smectite concretion, and of siliceous aggregates occurring in the pelagic "brown clays." Along the sedimentary section, the trace elements enriching the authigenic silicates and the Fe-Mn oxyhydroxides vary, depending on the marine environment. The proportion of clays and carbonates into the siliceous deposits controls the diagenetic evolution of silica making up the quartz aggregates from the "brown clay" or the cristobalite cherts.
Supplement to: Karpoff, Anne Marie; Hoffert, Michel; Clauer, Norbert (1981): Sedimentary sequences at Deep Sea Drilling Project Site 464: Silicification processes and transition between siliceous biogenic oozes and brown clays. In: Thiede, J; Vallier, TL; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 62, 759-771, doi:10.2973/dsdp.proc.62.131.1981