Paper Number: 819
Miocene to Recent Oceanographic and Climatic Histories from the Australian Northwest Shelf: Results from IODP Expedition 356
Fulthorpe, C.S1, Gallagher, S.G.2, Bogus, K.3, Christensen, B.A.4, Groeneveld, J.5 and Expedition 356 Scientists
1Institute for Geophysics, Jackson School of Geosciences, The University of Texas at Austin, 10100 Burnet Road, Austin, TX7 8758, USA; craig@ig.utexas.edu
2School of Earth Sciences, University of Melbourne, Victoria 3010, Australia
3International Ocean Discovery Program, Texas A&M University, College Station, TX 78845, USA
4Environmental Studies Program, Adelphi University, 1 South Avenue, Garden City, NY 11530, USA
5MARUM/Department of Geosciences, University of Bremen, D-28359 Bremen, Germany
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International Ocean Discovery Program (IODP) Expedition 356 (August-September 2015) drilled a latitudinal transect, across 10° latitude, of seven shelf and upper slope sites (Sites U1458-U1464) off Western Australia from the Perth Basin, through the Northern Carnarvon Basin, to the Roebuck Basin (Figure 1). RV JOIDES Resolution achieved continuously cored penetrations of up to 1.1 km. A major objective is to document the evolution of the Indonesian Throughflow (ITF), a critical component of global thermohaline circulation and a driver of the southward-flowing Leeuwin Current. These oceanic features have influenced the development of aridity in Australia and the genesis and variability of the Australian monsoon, as well as controlling reef growth along the west Australian margin. An additional objective is to obtain improved subsidence histories along the transect to evaluate the contribution of large-scale geodynamic processes, such as dynamic topography induced by mantle anomalies, on the region’s sedimentary systems.
Figure 1. Locations of IODP Sites U1458-U1464.
Ongoing research will evaluate biogeographic and water temperature (using multi-proxy organic geochemistry and Mg/Ca) evidence of ITF connectivity, produce high-resolution stable isotopic and sediment compositional records, and quantify the unusually high subsidence rates observed at several sites, which are probably linked to dynamic topography. Integration of core and seismic data will allow documentation of the onset of post-Miocene reef and carbonate platform development, previously poorly constrained in this region.