SEDIMENTOLOGICAL STUDY OF THE SEA BOTTOM SEDIMENTS IN AND AROUND THE ROSS SEA CONTINENTAL SHELF, ANTARCTICA

Sediment cores collected in and around the Ross Sea, Antarctica, are described and discussed based on sedimentological data, such as visual descriptions, sedimentary structures, magnetic susceptibility, sand contents, and water content. On the Ross Sea Continental Shelf, the core sequences contain two lithologic units, soft diatomaceous mud in the upper and compound glacio-marine sediments in the lower. The lower lithologic unit suggests that highly ice-sheet influenced sedimentation existed in glacial times in the Ross Sea. The core sequences on the continental slope and deep-sea basins off the Ross Sea comprise foraminiferal ooze, siliceous mud, and terrigenous mud, sometimes with laminated parts. The laminated parts of the core sequences suggest that strengthened bottom water influenced sedimentation, probably in glacial times. The sedimentary environment in the Late Quaternary is reconstructed based on the core data