Deep-Water Circulation over the Last Two Glacial Cycles Reconstructed from Authigenic Neodymium Isotopes in the Equatorial Indian Ocean (Core HI1808-GPC04)

Abstract We reconstructed the past deep-water character of equatorial Indian Ocean using isotope ratio neodymium ( ε Nd ) in Fe–Mn coating mixed-species foraminifera. When compared with previous records at same site (ODP 758) and another to west (SK 129), three datasets were consistent showed glacial-interglacial variations, even though other two extracted from different media (cleaned foraminifera bulk sediment leach). This confirms that while foraminiferal is preferred medium for reconstructing bottom water records, carbonate-dominated lithologies, weak acid extraction also a viable option offering high-resolution capabilities. lithology includes volcanic particles or high organics, protocol may need be adjusted guard against detrital contamination slight correction applied. During glacials, deep waters bathing had larger AABW component during interglacials NADW component. Our HI1808-GPC04 record supplements ODP 758 interval prominent signal (MIS 6/5 transition MIS 7) reveals regional effects some non-radiogenic intervals. The smaller differences between HI1808-GPC04/ODP SK 129 seem reflect input river systems boundaries.