Five years and going strong


The Sensitive High Resolution Ion MicroProbe IIe.

The Sensitive High Resolution
Ion MicroProbe IIe.

When you need to confirm your age, it is easily done with a birth certificate, but in some cases, such as determining the age of rocks to assist the search for new mineral and energy resources, it requires highly sophisticated, specialised equipment.

That equipment is the Sensitive High Resolution Ion MicroProbe, commonly called SHRIMP. It allows scientists to establish the age of rocks, but it won't tell you your birthday.

Since its installation at Geoscience Australia five years ago, the SHRIMP has carried out more than 62 000 uranium-lead analyses on geological materials ranging from recent volcanic rocks in Papua New Guinea and New Zealand to more than three billion year old crust on South Australia's Eyre Peninsula.

During the past five years the combined efforts of Geoscience Australia's Mineral Separation and SHRIMP laboratories has also resulted in the analysis of 500 samples from the State and Northern Territory geological surveys under the National Geoscience Agreement.

The SHRIMP Laboratory has adapted Australian Federal Police forensic techniques used to locate traces of gunshot residue. The technique has also allowed geochronologists to identify monazite crystals measuring only 10 micrometres, or 0.01 of a millimetre, in diameter. Monazite can be associated with deposits of gold and rare earth elements.

In addition to Geoscience Australia's geochronology program, the SHRIMP is the demonstration instrument and research development tool for the manufacturer, Australian Scientific Instruments, which has resulted in analyses of boron isotopes in the mineral tourmaline, uranium-series analysis of a 700 year old volcanic rock and even sulphur in human hair. Development work is continuing to demonstrate analytical capability across the periodic table of elements.

Geochronologist, Dr Keith Sircombe, says that during the past five years the SHRIMP has provided the mining industry and others with valuable geological age and isotopic data to reduce exploration risk.

"Future planning for the SHRIMP includes continuing development of world-class laboratory practices and an exciting contribution to analytical programs associated with the search for new geological terranes," Dr Sircombe said.