Sarah MacLeod

Madsen Building (F09), Room 414
Phone: +61 2 9351 8093

Email:

Supervisor: Professor Dietmar Müller
Assoc. Supervisors: Dr Simon Williams
Dr Yatheesh Vadakkeyakath, National Institute of Oceanography (CSIR), Goa, India

Research

MSc Project: Reconstructing the evolution of mid-ocean ridges and passive margins in the Indian Ocean for the Jurassic and Early Cretaceous and implementing a deforming plate model.

This project will seek to improve upon existing tectonic reconstructions for the early separation of Africa-Antarctica-India-Australia and Madagascar. The project will integrate available geological and geophysical data from the region, to improve constraints upon relative plate motions.

The project will have two distinct phases, addressing the objectives below:

I. To develop a refined seafloor spreading history for the Indian Ocean, incorporating all extinct or failed rift systems, micro-continents and micro-plates using crustal thickness maps and geological and geophysical evidence; thereby improving upon the reconstruction and rotation poles for all landmasses at the margins of the Ocean.

II. To build a deforming plate model for the stretched continental margins of the Indian Ocean, which will incorporate lithospheric extension to arrive at a more accurate tectonic reconstruction, implementing the deforming plate methodology of Williams et al. 2011.

This methodology may assist in refining the pre-breakup fit reconstruction and a model for the passive margins of the Mesotethys and Neotethys before closure and collision.

Project Funding:
The project will be funded in part from the Australia-India Strategic Research Fund (AISRF) project "Towards a unified East Gondwanaland reconstruction and its implications for Himalayan Orogeny”.

Lead investigators: Dietmar Müller (EarthByte Group, School of Geosciences) and Yatheesh Vadakkeyakath, National Institute of Oceanography (CSIR), Goa, India

AISRF Project Summary:
The plate kinematics leading to the separation and migration of Gondwanaland fragments and the adjoining deep offshore regions remain poorly constrained. A successful French-Australian collaboration unraveled a new high-resolution plate model of the Australia-Antarctica-India plate boundaries, while similar information was obtained for the India-Antarctica-Africa plate boundaries under two recently concluded Indo-French collaborations. We now propose to synthesize these two results into a unified model of high-resolution plate reconstructions for the East Gondwanaland fragments. These synthesized results will allow testing different continental fit reconstruction models by using a variety of reconstructed data sets and different plate circuits while accommodating various known microcontinents/ continental fragments. The revised reconstruction models are expected to provide tighter constraints for India-Eurasia collision and Himalayan Orogeny. We also hope to extend our studies to understand the genesis of some of the major tectonic features of the region, such as the 85° East Ridge.

References

  • Williams, S. E., Whittaker, J. M. and Müller, R. D., 2011. Full-fit palinspastic reconstruction of the conjugate Australian-Antarctic margins. Tectonics, 30, doi: 10.1029/2011TC002912.

Publications

Papers

  • Solomon Buckman, Allen P. Nutman, Jonathon Aitchison, Joseph Parker, Sarah Bembrick, Tom Line, Hiroshi Hidaka and Tomoyuki Kamiichi (In Press, accepted manuscript). The Watonga Formation and Tacking Point Gabbro, Port Macquarie, Australia: Insights into crustal growth mechanisms on the eastern margin of Gondwana. Gondwana Research, doi:10.1016/j.gr.2014.02.013.

Theses

  • Bembrick, S. (2012). An interpretation of the geological history of the units exposed at the coast of Port Macquarie, NSW, Australia, by detailed field mapping and synthesis with previous works. Completed for BSc Geology (Hons), Birkbeck University of London.