Schedule 5 Final Report: Geophysics and Drilling Collaborations Program 2024, Round 17

Abstract

This study was co-funded under the 'Innovative Targeting' category of NT Government's Geophysics and Drilling Collaboration Program. The study involved implementation of a newly developed quantum gravity technique called Gravio which is offered by Atomionics Australia Pty Ltd. The Ringing Rocks prospect in the Barrow Creek region was chosen for the implementation due to the large size and perceived lithium potential of this pegmatite target and the poor previous gravity coverage in this area. The aim was to see if the Gravio technique could achieve detailed resolution of the structure (ore structures) which the pegmatites have exploited. Gravio is an absolute quantum gravimeter that measures minute variations in the gravitational field using cold atom interferometry, a technique that exploits the wave-nature of atoms. These atoms are highly stable and do not have any inherent sensor drift. The system is installed in a vehicle and driven around the area of interest to take measurements. The project was divided into two phases. Phase 1 was executed between October and November 2024 and Phase 2 was conducted from May to June 2025. The surveys included a high-resolution (50-200m spaced) area of 15 square kilometres and a regional (400m spaced) resolution area of 67 square kilometres, including a 'classical' gravity survey with a Scintrex CG-5 for comparison purposes. A number of operational challenges were faced during the implementation of this new technology which limited the amount of data collected. However, comparison between the data obtained from classical and quantum gravimetry were good, and revealed Gravio's ability to capturing shorter wavelength signals, indicative of finer geological features, which will be further improved once the moving platform is implemented in the next stage of its development.