Ti Concentrations in Zircon from the Boggy Plain Zoned Pluton; Implications for Zircon Petrology and Hadean Tectonics

The Ti-in-zircon thermometer is employed in the zoned, high temperature (>1000°C) Boggy Plain Pluton. Measurements were made on zircon in rocks ranging in bulk compositions from gabbro to aplite. Apparent crystallization temperatures range from about 820-750°C (corrected for non-unity TiO2 activity). There is no correlation of Ti concentrations with rock type. The distributions of apparent crystallization temperatures are compared with a simple forward model. The model captures broad characteristics of the distributions, but has important differences. These differences may be the result of either sampling bias and/or a non-monotonic P-T-X history of the magma chamber during zircon crystallization. Titanium concentrations are generally higher than those in the Hadean zircon suite from the Jack Hills of Western Australia.