On the foundering of carbonate platforms and coral reefs

Wilson, Moyra E.J.1, Arosi, Hamed, A. 1, Loche, Marco1, Webster, Jody2,

1School of Earth Sciences, University of Western Australia, Perth WA, 2University of Sydney, Sydney, Australia. Correspondence e-mail: Moyra.wilson@uwa.edu.au. 

Carbonate systems and coral reefs build amongst the largest edifices on the planet, are able to keep-up with most tectonic or glacio-eustatic induced sea-level rises and consequently the foundering of many platforms is often enigmatic.  The cause of demise of platforms and the deposition of potential overlying seal units are critical for understanding thresholds for carbonate platform survival as well as petroleum systems evaluations in better understanding relationships between reservoirs and caprocks.

The paradox of foundering of carbonate platforms has been variously linked to ‘drowning’ via (1) fast glacio-eustatic sea-level rise, (2) tectonic induced sea-level rise, (3) nutrient and/or clastic poisoning and (4) subaerial exposure, shut-down of the carbonate factory and a subsequent inability to ‘catch-up’ on subsequent reflooding. Despite better understanding of the foundering of carbonate platforms being critical for their survival, evaluations of the sedimentary, geochemical and petrophysical signatures of each of the potential causes for demise remain understudied.

This study will evaluate the sedimentary, geochemical and diagenetic signatures across key outcrop analogue sections and subsurface reservoirs to understand the impacts of different causes of foundering on reservoir and caprock development. The research investigates: (1) both short- and longer-term (~> 1 Ma) transgressive drowning successions of carbonate platforms, (2) nutrient/or and clastic influenced land-attached, nearshore carbonate foundering, (3) carbonate platforms affected by karstification prior to drowning, and (4) volcanogenic smothered systems.


Biography

Moyra is a Senior Lecturer at UWA, Perth, with 30 years academic/industry experience focusing on the carbonate and reefal systems of Australasia, marine palaeoenvironmental change and reservoir potential.  Moyra’s awards include the Lyell Fund (Geological Society of London), Wiley Best ‘Sedimentology’ Paper, Curtin University Fellowship, and Australian Bicentennial Award. 

About the GSA

The Geological Society of Australia was established as a non-profit organisation in 1952 to promote, advance and support Earth sciences in Australia.

As a broadly based professional society that aims to represent all Earth Science disciplines, the GSA attracts a wide diversity of members working in a similarly broad range of industries.