01whole.pdf (31.74 MB)
Download file

Characterising rocks dredged from the Gulden Draak microcontinent

Download (31.74 MB)
thesis
posted on 28.03.2022, 19:27 authored by Robyn Gardner
Gulden Draak is a bathymetric feature 2-3 kilometres below the surface of the Indian Ocean 2,000 kilometres west of Perth, Western Australia. Four samples were selected from the continental rocks dredged from the knoll, three orthogneisses and one paragneiss. Minerals and textures indicate the samples were subjected to amphibolite to granulite facies metamorphism in multiple metamorphic events. U-Pb and Lu-Hf isotope analysis shows the samples have undergone a complex history of emplacement, metamorphism and partial remelting. The orthogneisses were originally emplaced prior to 2800 Ma, 1290 Ma and 1200 Ma respectively. Two samples, an orthogneiss and the paragneiss have Archaean age zircon cores. These events have been correlated with the Nornalup Complex in the Albany-Fraser Orogen formed as the Mawson and Yilgarn cratons collided. All samples were subsequently impacted by the Kuunga Orogen at ~500Ma: by isotope resetting, zircon partial melting and recrystallisation, growth of new metamorphic rims and/or lead loss. Lead loss evidence for the rifting event at ~136 Ma is also seen. At the time of the Gondwana breakup Gulden Draak was located south of the Naturalise Plateau very close to the Greater India-Antarctica-Western Australia triple point.

History

Table of Contents

Chapter 1. Introduction -- Chapter 2. Regional geology -- Chapter 3. Fieldwork -- Chapter 4. Petrography -- Chapter 5. Mineral chemistry -- Chapter 6. Major & minor elements -- Chapter 7. Zircon morphology and composition -- Chapter 8. U-Pb dating of zircons -- Chapter 9. Hafnium isotopes -- Chapter 10. Conclusions.

Notes

"GEOS899 Research Project" -- Empirical thesis. Bibliography: pages 81-84

Awarding Institution

Macquarie University

Degree Type

Thesis masters coursework

Degree

MSc, Macquarie University, Faculty of Science and Engineering, Department of Earth and Planetary Sciences

Department, Centre or School

Department of Earth and Planetary Sciences

Year of Award

2012

Principal Supervisor

Nathan Daczko

Rights

Copyright Robyn Gardner 2012. Copyright disclaimer: http://mq.edu.au/library/copyright

Language

English

Extent

1 online resource (x, 90 pages illustrations (some colour), maps (some colour))

Former Identifiers

mq:70467 http://hdl.handle.net/1959.14/1264534