A hand-held acoustic command unit was deployed to release the platform. The sedimentary section at Site 1201 consists of two lithostratigraphic units. These sediments are composed of detrital volcaniclastic material from the Palau-Kyushu Ridge that has been reworked by turbidity currents. The diagenetic history is documented by changes in clay mineral and zeolite assemblages with depth which are consistent with changes in pore water composition. A 2.5-m thick marine claystone occurs immediately above the basaltic basement contact at 509 mbsf.
Basement rocks consist of highly altered basaltic pillow lavas.
Glassy pillow margin rims are observed in the core along with hyaloclastitic intervals. The rocks are aphyric to moderately plagioclase phyric in discrete intervals. Hypocrystalline rocks are most abundant in the upper part of the core but decrease with depth, correlating with the degree of alteration, which is very high in the upper tens of meters and gradually decreases in the lower part of the core. Alteration products are mainly clay minerals and zeolites in addition to minor carbonate. The original mineralogy consists of plagioclase, clinopyroxene in variable amounts increasing with depth, olivine and opaques.