Carra Georgina Williams

cwilliams

Geocoastal Research Group

School of Geosciences, The University of Sydney

Carra Williams is a PhD candidate at the University of Sydney, Australia. Her current research investigates the evolution and development of the carbonate platform and reefs in Australia’s North West Shelf throughout the Quaternary period. The focus is on Scott Reef and generating numerical models based on observational data such as core, thin section, seismic and high-resolution bathymetric data. By comparing observed data with forward modelled data, it becomes easier to unravel how carbonate settings responded in the past to changing environmental conditions and concurrently to better predict coming changes.

Carra has a Bachelor of Science from Cardiff University and a Master of Science from the University of Aberdeen with a distinction for her thesis titled ‘’Evaluation of an Intra-Volcanic Carbonate Build-up, offshore West Africa.’’ Carra has been working in the oil and gas industry for the past seven years, most recently as a senior Geologist with Schlumberger, which included working with global clients on forward stratigraphic models using Petrel GPM (Geological Process Modelling) software.

RESEARCH KEYWORDS

Carbonate platforms & Coral Reefs
Numerical Modelling/forward stratigraphic modelling
Quaternary carbonate geology
North West Shelf
Great Barrier Reef

RESEARCH PROJECTS

Compare and contrast Quaternary coral reef and carbonate platform development on the North East Australian margin (GBR) and North West Australian margin over the last 1 million years using forward stratigraphic modelling tools

RESEARCH ABSTRACT

The growth and development of carbonate platforms and reefs is complex and governed by multiple factors such as; sea level, sea surface temperature, ocean currents and sediment flux. Carbonate platform and reef environments on the North West and North East Shelves of Australia are controlled by differing combinations of these factors due to their different tectonic and oceanographic settings. Additionally, there is an inherent uncertainty around how each shelf responded to regional and global cyclic environmental events in the recent geological past and how these events correspond on opposite sides of the Australian continent.

The Scott Reefs on the North West Shelf of Australia sit on the edge of a continental margin, where relative base level changes are recorded by coral reef assemblages through time and space. Recent data acquisition (sediment and rock cores) and re-processing of 3D Seismic data in this region provides a unique opportunity to investigate those changes.

The North West Shelf underwent dramatic climatic and oceanographic changes throughout the Quaternary period; most notably, a rise in sea level amplitude and decreasing frequency during the Mid Pleistocene Transition (MPT), between 0.6-0.8Ma and the associated change in regional climate from wet to dry. The timings of coral reef turn on and off are insufficiently understood with respect to these changes.

Forward stratigraphic modelling (FSM) is a technological method that can be implemented to unravel the recent geological evolution of this region and compare the findings with the relatively better resolved carbonate system on the NE margin of Australia (Great Barrier Reef).

By coupling forward stratigraphic modelling with observational data analysis, 4D geo-eco-morphological models of these carbonate systems can be designed to better resolve their evolutionary history, as well as outputting high resolution past relative sea level curves, carbonate accretion rates and tectonic variations for this poorly studies region and time period. These outputs can also be used to constrain ideas about how these specific and other analogous carbonate systems might change in response to uncharacteristic environmental conditions such as those witnessed today and anticipated in the near future.

CONFERENCE PROCEEDINGS/ PUBLICATIONS

2021

AAPG/SEG ACE 2021 – 26^th September 2021

Williams C., Courtade S., Dutra H.P.L., Lejri M., Habel W.B., Salomonsen P., 2021.
Reproducing carbonate sedimentary processes and architectures with stratigraphic forward modelling. Oral Presentation.

2021

GESSS 2021 – 29th November 2021