2025 Q1 technical highlightS

 

This episode features the following technical highlights:

• ‘Hobby’ fluid automation technology from the team at Curtin University
• In situ Lu-Hf and Re-Os geochronology for mineral exploration from the team at UofA; and
• Completion of the Northern Gawler NDI Campaign in collaboration with the Geological Survey of South Australia and DIG CT.

IN SITU LU-HF AND RE-OS GEOCHRONOLOGY FOR MINERAL EXPLORATION

Contact our Project Leader: Stijn Glorie (UofA)

The Program 3 research team has developed an analytical workflow to obtain robust radiometric dates on a range of minerals that are commonly associated with mineral deposits (apatite, REE-phosphate, carbonate, fluorite, molybdenite, epidote, garnet). These minerals can now very quickly, directly be dated from thin section or rock block, in cogenetic context with ore minerals.

This new ability to constrain the timing of crystallization of these hydrothermal minerals advances understanding of the timing of fluid systems which transported and/or concentrated ore minerals.

Defining a robust temporal framework for ore genesis and remobilization is crucial for mineral exploration. Mineralisation occurs in distinct events throughout geological history and different minerals form in different tectonic scenarios. The new analytical capabilities give the explorer a robust toolbox to rapidly define geological time in their exploration areas.

A significant advancement in mass-spectrometer technology has enabled interference-free detection of same-mass parent-daughter isotopes pairs, opening up new opportunities for radiometric geochronology. The radiogenic daughter products of Hf and Os react with gasses inside the mass-spectrometer to form molecules with a higher mass, while the parent isotopes of Lu and Re don`t react. This chemical separation within the mass-spectrometer allows direct measurement of Lu-Hf and Re-Os isotope ratios at orders of magnitude faster rates compared to conventional isotope-dilution methods. We demonstrated the method on phosphates, carbonates and molybdenite within IOCG systems in the Olympic Province (South Australia) and discovered a new Cu system in the northern Gawler Craton. We also dated late fluorite and dolomite veins that transport Cu from the IOCG-rich basement to the Stuart Shelf cover sequences. Latest developments include (1) dating (ultra)mafic rocks with apatite and basalts via epidote coronas on amygdales, (2) dating organic-rich shales and young molybdenite deposits, (3) dating banded-iron formations using authigenic apatite, and (4) using detrital apatite and garnet geochronology as vectoring tools towards mineralisation.

The new analytical capabilities give explorers access to geological time constraints within days from collecting samples, allowing faster decision making, reducing exploration search space and obtaining new vectors to mineralisation. This will result in increased exploration expenditure and discoveries in Australia.

 

NORTHERN GAWLER NDI CAMPAIGN IN COLLABORATION WITH THE GEOLOGICAL SURVEY OF SOUTH AUSTRALIA

Contact our Program Leader: Anthony Budd (Geoscience Australia)

The Northern Gawler NDI is a geoscientific drilling program that partners government and researchers to undertake a scientific drilling program to improve geological knowledge in the northern Gawler Craton area of South Australia.

One of the aims of MinEx CRC is to attract exploration and discovery into areas which have not yet been explored. This work is part of a long-running precompetitive geoscience program which will improve understanding of the mineral, energy and groundwater potential of the region, confirm modelled depth of basement cover and provide new information as a regional greenfields ‘mapping with a drill rig’ program in northern South Australia.

The Northern Gawler project area encompasses a crucial zone that could aide in understanding the structural architecture of the northern Gawler Craton.

The drilling program has been planned to explore terrane correlation and interrogate how the bits of the northern Gawler Craton fit together (Nawa Domain, Mabel Creek Ridge, and Peake and Denison Inliers).

The geological information gained from this program will assist GSSA and MinEx researchers to correlate northern Australia (Aileron/Arunta, Mt Isa) and other parts of South Australia (Peake and Denison, Gawler Craton) to the northern Gawler Craton.

The program is providing answers about the different basement rocks and metamorphic history. Preliminary field data will be provided in the Northern Gawler NDI Dashboard.

The Northern Gawler NDI aims to help inform the South Australian Discovery Mapping project in Northern Gawler Craton, and develop mineral potential in the area through detailed logging and sampling of NDI material for many potential commodities (including Cu-Au (IOCG, ISCG), REE, BHT base metals and build on existing models (e.g. “younger” Cu systems).

 

‘HOBBY’ FLUID AUTOMATION TECHNOLOGY

Contact our Project Leader: Masood Mostofi (Curtin University)

Curtin University’s innovative Hobby Fluid Automation system is entering the final stages of preparation for field deployment. The mechanical structure is now complete, core components installed, and sensor and control systems integrated, the project is now progressing into laboratory commissioning.

The Hobby system is designed to fully automate the preparation and management of drilling fluids, showcasing how data-driven optimisation can significantly enhance the efficiency and performance of traditional drilling operations.

Engineered to simplify and streamline the drilling process, Hobby combines full automation with advanced analytics to enable intelligent decision-making and process optimisation.

Key features include an onboard tank for transporting and reusing drilling fluids between boreholes and a solid separation unit capable of removing both coarse and fine particles. The system leverages Curtin’s proprietary Universal Drilling Fluid (UDF), with algorithms dynamically adjusting UDF concentrations based on pre-drill plans and real-time data.

With lab commissioning underway, researchers are eagerly preparing for field trials scheduled to begin in 2025.