13. CRETACEOUS INTERACTIONS BETWEEN VOLCANISM AND SEDIMENTATION IN THE EAST MARIANA BASIN, FROM MINERALOGICAL, MICROMORPHOLOGICAL, AND GEOCHEMICAL INVESTIGATIONS (SITE 585, DEEP SEA DRILLING PROJECT)1

At Site 585 of Deep Sea Drilling Project Leg 89 more than 500 m of volcaniclastic to argillaceous middle-Late Cre-taceous sediments were recovered. Analyses by X-ray diffraction (bulk sediment and clay fraction), transmission elec-tron microscopy, molecular and atomic absorption, and electron microprobe were done on Site 585 samples. We iden-tify four successive stages and interpret them as the expression of environments evolving under successive influences: Stage 1, late Aptian to early Albian—subaerial and proximal volcanism, chiefly expressed by the presence of augite, analcite, olivine, celadonite, small and well-shaped transparent trioctahedral saponite, Al hydroxides, Na, Fe, Mg, an