[M-IS23] [JJ] Paleoclimatology and paleoceanography

[MIS23-P20] Timing and characteristics of eolian-sand turbidites collected from the northeastern Arabian Sea

*Masafumi MURAYAMA^1,3, Kodai YAMASHITA², Yuhji YAMAMOTO³, Tomohisa Irino⁴ (1.Faculty of Agriculture and Marine Science, Kochi University, 2.Graduate School of Integrated Arts and Sciences, Kochi University, 3.Center for Advanced Marine Core Research, Kochi University, 4.Faculty of Environmental Earth Science, Hokkaido University)

Keywords:eolian-sand turbidite, northeastern Arabian Sea, sea-level change, marine core

The relationship of sea-level changes and climatic changes in late Quaternary with turbidite deposition is reported. We found two ungraded and massive sand layers which were intercalated in calcareous clay in a sediment core (ER-4; W.D. 3,550 m) collected from the northeastern Arabian Sea. The characteristics of these contained dominantly the gray colored, pellet shaped marble grains which were consist of well-sorted and well-rounded of fine to medium sands. According to these features, these sand layers could be described as redistributed eolian sand, so-called “eolian-sand turbidites” (Sarnthein and Diester-Haass, 1977), derived from Thar Desert. The timing of these turbidite occurrences were determined after Heinrich event 5 and L.G.M., respectively, in response to major glacial to interglacial sea-level shifts and variability in the NE-Indian monsoon climate change. Thus, the frequency of eolian-sand turbidites must be influenced by sea-level variations, by cyclic processes of climatic origin and by variations in the subbottom morphology.