(Table 1) Geochemistry of glass shards at DSDP Site 87-582 and 87-583

In the Leg 87A holes, 45 ash layers were sampled in Recent to upper Pliocene strata. The main volcanogenic deposits came from single eruptions or subcontemporaneous eruptions of cognate volcanoes. Some of them are mixed ashes produced from multiple eruptions and accumulated in reworked sediments. The petrographic and geochemical patterns indicate rhyolitic and dacitic compositions; andesitic glasses are scarce. We infer a magmatic affinity with calc-alkaline sources and a possible origin from the volcanic arc of southwestern Japan. A few samples may originate from the alkaline volcanism of southwestern Japan or the area south of Korea and the Sea of Japan.

(Table 1) Benthic foraminifera at DSDP Site 72-516

DSDP Site 516 contains a complete middle Eocene to lower Miocene interval with a well-developed Oligocene sequence that is more than 300 m thick. In this paper, the most important and characteristic benthic foraminiferal species from this interval are described and illustrated, and their quantitative and biostratigraphic distribution is given. Middle Eocene benthic assemblages, derived from pelagic intercalations in a partly turbiditic sequence, are low in diversity. Benthic assemblages of fairly high diversity occur in limestones, chalks, and oozes of the upper Eocene to lower Miocene. The consistently high rate of new species appearances at Site 516 during late Eocene and Oligocene contrasted greatly with the very slow rate of change in abyssal faunas at that time; there were no significant faunal changes at the Eocene/Oligocene boundary. The assemblages are dominated by Cibicidoides (mostly C. ungerianus or C. kullenbergi) and Lenticulina. Buliminids were also important during the Eocene and early Oligocene. Faunal comparison with other Atlantic DSDP sites and drill holes in the Gulf of Mexico suggest an approximately mid-bathyal (500-1500 m) depth of deposition during late Eocene and Oligocene.