Tectonic, Oceanographic, and Climatic Controls on the Cretaceous-Cenozoic Sedimentary Record of the Australian-Antarctic Basin

Maintenance and Update Frequency: asNeeded Statement: Seismo-stratigraphic boundary layers of key sedimentary supersequences are interpreted, based on multichannel seismic data offshore Australia and Antarctica. The interpreted horizons are exported and used to compute interpolated 0.5° grids in TWT...

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Other Authors: IMAS Data Manager (publisher), Institute for Marine and Antarctic Studies (IMAS), University of Tasmania (UTAS) (hasAssociationWith), Joanne Whittaker (hasPrincipalInvestigator), Sauermilch, Isabel (pointOfContact), Sauermilch, Isabel (hasPrincipalInvestigator), Sauermilch, Isabel (author), Whittaker, Jo (hasPrincipalInvestigator), Whittaker, Joanne (hasPrincipalInvestigator), Whittaker, Joanne, Assoc/Prof (hasPrincipalInvestigator), Whittaker, Joanne, Dr (hasPrincipalInvestigator)
Format: Dataset
Language:unknown
Published: Australian Ocean Data Network
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Online Access:https://researchdata.edu.au/tectonic-oceanographic-climatic-antarctic-basin/1357101
https://doi.org/10.25959/5ba2cae0eb62a
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Summary:Maintenance and Update Frequency: asNeeded Statement: Seismo-stratigraphic boundary layers of key sedimentary supersequences are interpreted, based on multichannel seismic data offshore Australia and Antarctica. The interpreted horizons are exported and used to compute interpolated 0.5° grids in TWT (s). For each key horizon, velocity grids are computed using the interval velocities from in total 1143 sonobuoy and ocean bottom seismometer (OBS) stations (after Whittaker et al., 2013b; Fig. 1a) as a function of TWT. Horizon grids in depth (km), sediment thickness (“isopach”) grids and volumes for each supersequence are calculated and reconstructed back in geological time (Fig. 8 – 67 Ma, Fig. 9 – 43.8 Ma) using GPlates 2.0 and the plate model of Matthews et al. (2016). Understanding the patterns and characteristics of sedimentary deposits on the conjugate Australian-Antarctic margins is critical to reveal the Cretaceous-Cenozoic tectonic, oceanographic and climatic conditions in the basin. However, unravelling its evolution has remained difficult due to the different seismic stratigraphic interpretations on each margin and sparse drill sites. Here, for the first time, we collate all available seismic reflection profiles on both margins and use newly available offshore drilling data, to develop a consistent seismic stratigraphic framework across the Australian-Antarctic basins. We find sedimentation patterns similar in structure and thickness, prior to the onset of Antarctic glaciation, enabling the basin-wide correlation of four major sedimentary units and their depositional history. We interpret that during the warm and humid Late Cretaceous (~83-65 Ma), large onshore river systems on both Australia and Antarctica resulted in deltaic sediment deposition offshore. We interpret that the onset of clockwise bottom currents during the Early Paleogene (~58-48 Ma) formed prominent sediment drift deposits along both continental rises. We suggest that these currents strengthened and progressed farther east through ...