CHARACTERIZATION AND ORIGIN OF FE~(3+)-MONTMORILLONITE IN DEEP-WATER CALCAREOUS SEDIMENTS (PACIFIC OCEAN, COSTA RICA MARGIN)

摘要

Millimetric to centimetric green grains widespread in pelagic calcareous sediments recovered at a water depth of 3000 m near the Costa Rica margin were studied by XRD, SEM, TEM and FTIR. Samples were collected during the TICOFLUX II expedition, from the upper bioturbated part of four sedimentary cores (0.13-3.75 metres below seafloor). The sediments are calcareous and siliceous nannofossils oozes (coccoliths, diatoms, radiolarian, ...).