Kimberlites, Diamonds and Eclogites in South Australia

Fields of Research

• Igneous geology
• Geochemistry
• Geochronology
• Metamorphic geology

Project Details

Associated with Gondwanan break-up and mantle plume activity, SE Australia is the site of a range of alkalic Mesozoic magmatic provinces. These Jurassic to Cretaceous suites have representatives in NSW, Victoria , Tasmania and in South Australia. In South Australia they are of Jurassic or Triassic age, represented by lamproite and kimberlite dykes. These intrusions are partly diamondiferous and some transport suites of exotic, high pressure xenoliths of mantle and lower crustal origin. These rocks are the object of an active diamond exploration industry.

In this project the PhD candidate will study both the host dyke-forming magmatic rocks as well as the hosted xenoliths. These include samples of mantle peridotite, eclogite and mafic granulite. These represent a unique record of the evolution of the lithospheric mantle and Moho beneath the SE Gondwanan cratonic margin. The role of eclogite metamorphism is potentially critical in the early Palaeozoic isostatic history of the Adelaide foldbelt.

The project will involve two strands:

• Geochemical and isotopic study of the host kimberlite and their phenocrysts to determine source and origin and diamond source potential.
• Geochemical and metamorphic P-T studies and Sm-Nd geochronology on the xenoliths to determine the history of the sub-continental lithospheric mantle, Moho underplating events and the age of eclogite mineral growth.

Supervisors

The project will derive some support from Flinders Diamonds Ltd.