Applied Spectra Alphachron - Automated Helium Thermochronology

During the course of research on the 4D evolution of ore systems, the CSIRO DEM found the need to develop instrumentation for rapid and automated analysis of mineral samples, which became the Alphachron&trade. The Alphachron™ technology, based on an innovative helium extraction/measurement instrument, is being adopted by the market as a standard analytical platform allowing an accurate determination of the thermal history of the Earth’s crust.

Up to 25 mineral samples can be loaded into the laser chamber of the Alphachron™ and heated (approximately 1000°C for apatite, and approximately 1250°C for zircon) under vacuum for five minutes with a 915nm diode laser. The extracted gas samples are analysed to determine their 4He content. The gas extraction process is repeated to ensure all the gas has been removed from the sample and in order to provide each sample with a blank. Mineral standards are analysed in each group of samples. Parent mineral concentration is subsequently determined by ICP-MS analysis of the sample.

An increase in the number of research institutions around the globe utilizing uranium-helium thermochronometry for applications including mineral and petroleum exploration, geohazards assessment, and continental evolution studies, has prompted demand for a world-first technology developed by CSIRO Exploration & Mining and manufactured by Applied Spectra.

Uranium-helium thermochronometry is a highly sensitive and cost-effective method of radiometric age dating that can be used to determine the thermal history of the Earth’s crust. The major benefit of this technology to the mineral resources industry lies in the ability to quantitatively determine the low temperature thermal histories of mineral belts (see references below) and petroleum basins. This data is fundamental in the exploration for deposits of minerals, as well as oil and gas.