- 2013-current Doctor of Philosophy (Earth Science), Australian National University
- 2009-2012 Bachelor of Science (Honours)(Geology), University of Ballarat
- 1994-1998 Master of Educational Administration, University of New England
- 1988-1989 Graduate Diploma in Curriculum, University of Melbourne
- 1982 Graduate Diploma in Education (Secondary), LaTrobe University
- 1979-1981 Bachelor of Arts (Social Science), LaTrobe University
1983-2009 Teaching and leadership roles in various Victorian secondary schools
Six years ago, I made a decision to resign my job after 26 years of employment in secondary school education. In 2009, I enrolled in a Bachelor of Science (Geology) to learn more about my life-long interest in earthquakes and volcanoes. It was quite a change to be suddenly on the other side of the lectern and sitting formal exams once again. Following an Honours project in economic geology (gold-granite mineralisation), I am currently studying subduction zone mechanisms for my PhD. Who knows where this may lead?
Devolatilisation reactions and fluid transport in the subduction zone
The causal linkage between oceanic plate subduction and arc volcanism at convergent margins has long been acknowledged in the earth sciences. Fluid-bearing minerals, such as amphibole, serpentinite, chlorite, mica and carbonates, which are present in the subduction zone, are subjected to increasing pressure and temperature as they are subducted. Eventually, they ‘devolatilise’ or undergo chemical and structural changes which releases their fluid. This fluid infiltrates the overlying mantle wedge, causing partial melting of the mantle rocks. This melt makes its way towards the surface, aggregating into magma chambers, the magma source for arc volcanoes.
Surprisingly little is known of the behaviour of many of these volatile-containing minerals when subjected to the high pressures and temperatures within the subduction zone. Even less is known of the mechanisms involved in fluid transportation from the subducting slab through the mantle wedge to surface volcanoes.
My study has two related aims:
- To establish the pressure/temperature conditions which define the dehydration of the H2O-bearing mineral chlorite, and the decarbonation of the CO2-bearing Fe, Ca and Mg-carbonate minerals using piston cylinder experiments on natural rocks sampled from various ophiolitic sequences.
- To examine the mechanism of fluid transport from the slab through the mantle wedge. Central to understanding this mechanism is whether the fluid is ‘free’, ‘bound’ or contained in melt. The Mélange Diapir model, which has gained much traction in current research literature, advocates a ‘bound’ fluid approach. Knowledge gleaned from the first part of this study should elucidate the fluid state in the sub-arc region and therefore test the strength of the Mélange Diapir model.