Neogene West Pacific tectonic influence on global climate via the Kuroshio Current

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The proposed research would produce a thorough quantitative foraminiferal study of 500 deep-sea sediments samples and aims to reconstruct the paleoceanographic changes in the West Pacific Ocean in the vicinity of the Kuroshio Current. The study is based primarily on coarse fraction (>150 micron) microscopic examinations. However, the micropaleontological work on planktonic and benthic foraminifera assemblages will be complemented by the analysis of stable isotopes (O18 & C13 ratios) measured on foraminifera extracted from selected samples. These analyses should confirm the stratigraphy of Site IBM-3C as well as inform the paleoceanographic and paleoclimatic interpretations obtained for the samples.At such a subtropical location (30deg N), the study of the planktonic assemblages is a very useful contribution for reconstructing changing surface conditions because glacial and interglacial faunal assemblages are very contrasted. In particular, the study will provide needed data about changes in the Kuroshio Current path, which are potentially linked to changing ENSO intensity in the Pacific Ocean. The study focuses on the last 6 Ma.In the area of the IBM and at 2114 water depth, the low resolution study of the benthic foraminifera assemblages extracted from 50 coarse fraction samples will provide some estimates of paleo-depth and deep-water environmental changes at a time resolution better than 1 Ma throughout the Neogene. All analyses will be performed in the Godwin Laboratory for Paleoclimate Research (Earth Sciences Department, Cambridge University) from carefully selected Neogene sediments taken on board JOIDES Resolution during Leg 350 by Dr. Vautravers sailing as a foraminifera expert.