Program > Browse abstracts by speaker > Mina Alana

The titanite-apatite-zircon (TAZ) geothermometer aims to provide a new tool for reconstructing pressure-temperature-oxygen fugacity (P-T-fO2) of magmatic rocks containing at least two of these minerals. We anticipate this tool to be useful for exploration of ore-bearing magmas such as gold or copper-mineralised porphyry intrusions. This study explores the partitioning behaviour of approximately 30 trace elements – including Ba, Cs, Hf, K, Mg, Mn, Nb, Pb, REE, Rb, Sr, Ta, Th, and U – between the minerals to refine thermometric and barometric calibrations.

Calibrating the TAZ system requires experimental synthesis of well equilibrated, large single crystals, which is a significant challenge. This study demonstrates that flux-assisted crystallization using a combination of KCl, NaHCO3, Mg(OH)2, and Ca(OH)2 effectively promotes crystal growth under these conditions. The starting materials for mineral synthesis include SiO2, TiO2, Ca5(PO4)3, CaCO3, and ZrF4.

The resulting crystals show promising sizes at the pressures and temperatures used up to this point: apatite crystals reach up to 100 µm and titanite grows to sizes above 50 µm. The use of seeded growth techniques enhances the zircon crystallization (overgrowths up to 50 µm) and reduces the unwanted formation of baddeleyite cores formation.

Future work will refine trace element partitioning models and apply this approach to natural systems to enhance the TAZ geothermometer's utility in mineral exploration and understanding ore-forming processes.