Résumé
Bulk sedimentary characteristics are presented from Integrated Ocean Drilling Program Site U1427, covering the depths greater than 250 m core composite depth below seafloor (CCSF-D_Patched), which spans the mid-Pleistocene transition. Site U1427 is located in the southern Sea of Japan/East Sea and was drilled during Integrated Ocean Drilling Program Expedition 346. Total organic carbon ranges from 0.5 to 3.1 wt%, total nitrogen ranges from 0.04 to 0.32 wt%, and carbonate (CaCO (sub 3) ) contents vary between 1.3 and 25.7 wt%. The carbon isotope ratio of organic matter (delta (super 13) C (sub org) ) values range from -24.9ppm to -20ppm. There is a broad correspondence between the geochemical parameters and the shipboard color reflectance index (b*), and this relationship becomes more pronounced from approximately 375 m CCSF-D_Patched upward. The b* index has been used as an indicator of glacial-interglacial cycles at Site U1427. Using this inference, the data suggest reduced marine productivity during glacials, whereas interglacials are characterized by relatively higher marine productivity. The interpretation of C/N ratios at Site U1427 may be complicated by an inorganic nitrogen component.