Dr. Moyra Wilson (University of Western Australia & GRG collaborator)
Title: ‘Equatorial carbonate systems: Cenozoic climate change and controlling influences’
Time & Location: Thurs 11:00 am, June 6th June & Conference Room 449 Madsen Building F09, USYD.
Abstract: The SE Asian carbonate record allows insight into the poorly known response of equatorial marine systems to regional and global change during the Cenozoic. Warm temperatures, together with common clastic, freshwater and nutrient influx as well as active tectonics and volcanism linked to basinal settings in the equatorial tropics, all have major impacts on carbonate deposition, platform development, demise and their subsequent alteration through diagenesis. Specific features of equatorial carbonate systems resulting from the combination of processes acting in the region include: common occurrence of photoautotrophs and heterotrophs, aragonitic and/or calcitic dominant mineralogies, lack of coated grains or aggregates, common associations with clastics, lack of associations with evaporites, and diversity of platform types, including oligophotic ones. Although equatorial carbonates fall into the warm water Photozoan Association, many of the features described above are at odds with models derived from their warm water, arid-zone counterparts. Instead a range of the equatorial carbonate features show some similarities with those formed in cool waters, and there have been difficulties separating carbonates from these two very different climatic regimes. The aim is that this work will lead to greater awareness and understanding of equatorial carbonate systems, and contribute to the development of globally predictive models to better understand past and likely future environmental change.