(Supplement T1) Clay mineral compositions at the Aleutian Basin of the Bering Sea from IODP sites 323-U1343

• Main Authors: Kim, Sunghan, Khim, Boo-Keun, Cho, Hyen Goo
• Format: Dataset
• Language: English
• Published: PANGAEA 2015
• Subjects: 323-U1343; AGE; Bering Sea; Bering Sea Paleoceanography; Chlorite; COMPCORE; Composite Core; Depth; composite; Exp323; Illite; Integrated Ocean Drilling Program / International Ocean Discovery Program; IODP; Joides Resolution; Kaolinite; Smectite; Smectite/(Illite+Chlorite) ratio; X-ray diffraction (Siemens/Bruker D5005); Alaska
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.855986; https://doi.org/10.1594/PANGAEA.855986

The clay mineral composition at IODP Exp. 323 Site U1343 in the Bering Sea was analyzed so as to unravel their provenance over glacial-interglacial cycles for the last 2.4 Ma. Smectite was negatively correlated with the sum of illite and chlorite; therefore, their ratio [S/(I + C)] was used as an indicator of clay mineral composition changes. In general, the S/(I + C) ratio was rather similar for glacial and interglacial periods during most of the last 2.4 Ma. In addition, these results overlap with those of surface sediments in the modern East Aleutian Basin, which suggests that smectite-rich clay particles are delivered from the Aleutians by the northward Bering Slope Current (BSC) rather than from rivers in western Alaska. However, some clay mineral compositions of the glacial periods after the Mid-Pleistocene Transition (MPT: 1.25-0.7 Ma) were characterized by low illite and relatively high smectite. During this period, extensive ice-rafting might have transported the smectite-rich clay particles to Site U1343 from the glacial shelf off Alaska and/or from glacial rivers from that area.