The Australian National University
Research School of Earth Sciences
document location: http://rses.anu.edu.au/rubatto_d/index.php?p=research&print=1

Current Research


Geochronology: Ion microprobe in-situ dating of U-Pb minerals (zircon, monazite, titanite, rutile, baddelejite) with a composite internal structure. Dating of minerals or mineral zones formed at different stages during the evolution of a rock unit in order to define detailed P-T-time paths and thus determine rates of geological processes (e.g. exhumation, subduction, cooling, melt residence and extraction). Combining different isotopic schemes in order to unravel complex geological evolutions.

Imaging: Cathodoluminescence and back scattered electron imaging as well as element mapping of datable minerals in order to understand diffusion profiles and mobility of isotopes and trace elements. Relating specific zoning patterns to crystallisation processes.

Trace element geochemistry: The composition of datable minerals such as zircon, monazite and titanite in different geological environments as indicator of coexisting paragenesis to relate age and metamorphism. Modelling the distribution of trace elements between major and accessory phases. Trace element partitioning between garnet and zircon as a tool to detect equilibrium crystallisation. The effect of melt and fluids on the trace element composition of datable minerals.

Metamorphic petrology: Main interests in the stability of U-bearing minerals over a wide range of P-T-fluid conditions. Understanding the chemical variation of such minerals with varying P-T and fluid composition in order to link datable minerals and metamorphic conditions. Quantifying solubility and mobility of trace and major elements in metamorphic and hydrothermal fluids.

Petrography: The study of microstructures in order to establish crystallization sequences and equilibrium/disequilibrium relations between major and accessory minerals. This aims to determine a genetic link between major and trace (mainly U-bearing) minerals, which in turns lead to the definition of reactions responsible for the formation of datable minerals. Study of solid and melt inclusions in datable mineral zones to constrain their formation in P-T space.

Field work: Using the field as natural laboratory for understanding the response of datable minerals to increase/decrease in temperature and/or pressure over continuous metamorphic sequences (e.g. Reynolds Range in central Australia). The study of tectonically complex terrains in which the behaviour of different chronometers can be investigated and compared within a variety of rock types and metamorphic grades (the European Alps).

Experimental petrology: Experimental determination of zircon/melt and zircon/garnet trace element distribution coefficients in a granitic composition. Project in collaboration with Dr J. Hermann. Stability of monazite and experimental determination of the monazite-allanite transition.