Illite is a clay mineral common in many sedimentary rocks

Argon dating meets exploration challenges

CSIRO applies advanced K-Ar and Ar-Ar laser dating technology to improve understanding of exploration targets for the petroleum industry.

• 14 September 2007 | Updated 14 October 2011

• Reducing exploration risk
• Uses of K-Ar and Ar-Ar dating
• Advantages/benefits of K-Ar and Ar-Ar dating
• Analytical services and facilities

Reducing exploration risk

The development of new technology to maximise successful exploration and reduce risk is a key focus for the oil and gas industry. Successful exploration relies on knowledge of basin formation and thermal history of sedimentary rock and hydrocarbon migration.

Potassium-Argon (K-Ar) and Argon-Argon (Ar-Ar) dating is used to determine the ages of rocks, minerals and the timing of fluid flow, providing clues on the rate of charge in a reservoir and oil and gas migration.

Based on this data, assessments of the reservoir quality can be made.

Uses of K-Ar and Ar-Ar dating

K-Ar and Ar-Ar dating of illite (a clay mineral common in many sedimentary rocks) can be used to determine:

• timing, duration and nature of hydrocarbon charge
• timing of hydrocarbon migration and entrapment
• timing of diagenetic events
• correlation of formations
• timing of deformation events
• timing of tectono-thermal events
• age provenance of detrital minerals.

Knowing the age of illite formation facilitates the construction of reliable geological models of basin histories.

This will enable oil and gas companies to better determine potential locations for drilling petroleum wells.

Advantages/benefits of K-Ar and Ar-Ar dating

Analytical services and facilities

CSIRO has a range of state-of-the-art equipment for K-Ar and Ar-Ar dating.

Facilities are located at the John de Laeter Centre for Mass Spectrometry at Curtin University of Technology, Perth, Western Australia, and include:

• high-resolution noble gas mass spectrometers, with online extraction and purification lines
• a double vacuum resistance furnace
• a 110 W infra-red 1064 nm Nd-YAG continuous laser, capable of spot analysis (100-200 µm spot size)
• a 6 mJ ultra-violet 213 nm pulsed laser, capable of high-resolution ablation (15-300 µm spot size)
• a clay mineral separation laboratory with high speed centrifuges and equipment for freeze-thaw disaggregation of rocks.

Services available for research and commercial purposes include:

• X-ray Diffraction, Scanning Electron Microscopy, Transmission Electron Microscopy - particle size analysis for clay characterisation
• general diagenesis investigations including petrography and diagenetic sequences
• vacuum encapsulation for 40Ar-39Ar dating of clays and fine-grained samples
• stable and radiogenic isotope analysis, including SHRIMP U-Pb micro-analytical dating equipment.

Learn more about Meeting energy exploration and production challenges with geoscience.