Earth Evolution Group
Deep Earth Cycles of Carbon, Water and Nitrogen
An Australian Laureate project is investigating the role of C, H and N in the evolution of the Earth.
The separation of the Earth into layers of crust, mantle and core, as well as later redistribution of chemical elements around different parts of the mantle and crust, is governed by melting of rocks.
Melting depends largely on the effects of a few light elements, C, H, O, N, which form the volatile components H2O, CO2, CH4, N2, H2 and NH3. Small amounts of these components cause the melting point of rocks to differ by up to 300˚C and are main drivers of plate tectonics. They determine that only small amounts of alkaline silicate and/or carbonate melts exist in many areas before major melting occurs. These incipient melts are the main cause of the compositional evolution of the Earth’s mantle.
The Earth Evolution group is investigating the effects of volatile components on melting in the mantle, and aspects of the cycling of these elements deep in the Earth. This entails high-pressure experiments, petrology and geochemistry on mantle rocks, their partial melts, and reactions between subducted crustal materials and the mantle.