Poster Presentation Australian Marine Sciences Association 2026 Conference

Australian Biogenic Carbonates: A Climate Thermometer? (139265)

Harrison Jarman 1 , Jessica Henley 1 , Syarifah Nur Alisya Binti Syed Alwi 1 , Karen Privat 2 , Alice MacDonald 3 , Ross Corkrey 4 , Indrani Mukherjee 1
  1. School of Biological, Earth and Environmental Sciences, University of New South Wales, Kensington, NSW, Australia
  2. Electron Microscope Unit, Mark Wainwright Analytical Centre, University of New South Wales, Kensington, NSW, Australia
  3. Centre for Ore Deposit and Earth Sciences, University of Tasmania, Hobart, Tasmania, Australia
  4. Tasmanian Institute of Agriculture, The University of Tasmania, Hobart, Tasmania, Australia

Biogenic carbonates can deposit in a range of settings determined by intersecting environmental variables. Temperature in particular is a useful discriminator for Australian biogenic shelf carbonates which are divided between lower latitude warm/tropical/photozoan and cool/temperate/heterozoan environments. An extensive series of lab-based research into the proxy applications of carbonate geochemistry is not reflected in the limited research applied to natural samples. This Honours thesis aims to characterise and discriminate the geochemistry of tropical and temperate end members of Australian biogenic carbonate sediments. Here we compare marine sediment cores from the Great Australian Bight (ODP Expedition 182) with sediment cores extracted from the North West Shelf of Australia (ODP Expedition 123 & IODP Expedition 356). A suite of whole-rock and in-situ geochemical techniques reinforces the feasibility of trace element geochemistry as a tool to discriminate between depositional end members. This project adds to a growing database of high-resolution geochemistry of biogenic carbonates deposited off Australia's continental shelf. In-situ analysis of biogenic carbonate sediments has the potential to mark a step change in understanding localised trace element incorporation, which is otherwise lost in whole-rock techniques.