Rock attracts interest in Temora

20 March 2012

Geologists inspect part of the rock outcrop containing the Temora reference material. Copyright Geoscience Australia.

Geologists inspect part of the rock
outcrop containing the Temora
reference material.
© Geoscience Australia

An outcrop of rocks which provides the benchmark for geochronology investigations around the world will itself be the subject of analysis in a study starting March 2012.

The rocks are found in a farm paddock near the New South Wales town of Temora and contain tiny crystals known as the TEMORA reference. These crystals are used by more than 100 geochemical and geochronology laboratories around the world, including in Geoscience Australia's Sensitive High Resolution Ion MicroProbe, or SHRIMP.

Now the University of Melbourne School of Earth Sciences is supporting an Honours thesis project to investigate the source of the TEMORA reference material in detail.

The researchers will consider whether the rock is as uniform as the analyses imply, why it is such a good source of the reference material for calibrating the age and geochemical composition of other rocks and if there is even better reference material nearby.

The project will include detailed geological mapping, petrographic studies and geochemical analysis of the original site and nearby granite outcrops to assess the overall uniformity of the rock and consider what makes the rock so special.

Geoscience Australia is the custodian of the reference material extracted from the rock and its Geochronology Laboratory will support the investigation by assisting with field work, sampling and analytical work.

The Geochronology Section Leader at Geoscience Australia, Dr Keith Sircombe, said the research is expected to result in further improvement in analytical processes and in the precision and accuracy of pre-competitive data provided to government agencies, resource exploration companies, researchers and the public.

"Despite its excellent international reputation, the source of the TEMORA reference material has never been examined in detail and the Honours project investigation is expected to give new insights into its future applications", Dr Sircombe said.

"The original reference material is a great example of scientific serendipity. It was discovered completely by accident and was almost overlooked for sampling. It will be very exciting to see what other discoveries the team from Melbourne can make," he said.

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