4:30 PM - 4:45 PM
[MIS01-10] History of the Leeuwin Current during the last 5 million years: Evidence from seawater Neodymium isotope variation
Keywords:Leeuwin Current, Neodymium isotopes, Off western Australia, Shallow-water carbonate, The last 5 million years, Carbon and oxygen isotope composition
Orbital- to million-scale variations in the ITF with the subsequent LC during the last 5 Myr are assumed to be related to the tectonic history of the Indonesian seaway restriction/unrestriction and paleoceanographic conditions (e.g., glacial/deglacial sea-level change, El Niño/La Niño-like state of the Pacific Ocean, and variability of the Western Pacific Warm Pool). However, the detailed timing of major restriction/unristriction of the ITF and the initiation and development of the Leeuwin Current are still unclear. The International Ocean Discovery Program (IODP) Expedition 356 recovered continuous Cenozoic (mainly the Miocene or younger) shallow-water carbonates, off northwestern Australia. Since some of the drilled sites are considered to be strongly influenced by the LC, Neodymium isotopes of foraminifers in the shallow-water carbonates are expected to record direct evidence of changes in the water mass along the Western Australian coastline. The objective of our research is to elucidate the long-term history of the Leeuwin Current during the last 5 Myr based on carbon, oxygen, and neodymium isotope records of foraminifers from IODP sites U1460 and U1463.