MinEx CRC, reportedly the world’s largest mineral exploration collaboration, has successfully completed its first National Drilling Initiative (NDI) campaigns, including a 10-hole, 4,000 m drilling campaign in the East Tennant area of the Northern Territory of Australia, to assess the mineral potential of basement rocks in the region.

While gold has been mined from the Paleoproterozoic rocks around Tennant Creek since the early 1930s, there has been almost no mineral exploration in the covered rocks to the east of Tennant Creek in the 90 years since, according to MinEx CRC.

“The East Tennant drilling campaign was designed to test stratigraphic and structural interpretations and assess the mineral potential of basement rocks to the east of the Tennant Creek mineral field,” MinEx CRC CEO, Andrew Bailey, said. “These basement rocks are under-explored and concealed by hundreds of metres of younger sedimentary rocks.”

The drilling campaign is part of a world-first scientific drilling program, the NDI, designed to understand the evolution of the Australia continent, provide clues about where to search for new mineral deposits and bring forward the next generation of mineral exploration technology, MinEx CRC says.

Included within the NDI campaign was a 1,750m drill hole (known as NDI Carrara 1) at a location near the Northern Territory/Queensland border, around 250 km northwest of Mount Isa. This hole was designed to capture geological and stratigraphic information from a previously unknown sedimentary basin, and to assess the basin for potential to host energy and mineral resources.

In collaboration with Geoscience Australia and geological survey organisations in every state and territory, the NDI will manage and deliver a seven-year program with multiple drilling campaigns spread across Australia.

Results from the drilling program have uncovered a range of igneous and metasedimentary rocks, enabled a better understanding of the structure and stratigraphy of the area and helped to refine pre-drilling interpretations of the region’s prospectivity, according to the collaborative project.

Drilling has also provided pinning points to constrain cover thickness, with prospective basement typically concealed beneath less than 200 m of Georgina Basin sediments and less than 30 m of Cambrian basalt of the Kalkarindji Suite.

Geoscience Australia’s Chief of Minerals, Energy and Groundwater Division, Dr Andrew Heap, said: “We are proud to be a participant of the MinEx CRC through our Exploring for the Future program, which identified the region as a highly-prospective frontier. The drilling results are confirming this view and will support the continued development of the Barkly Region.

“A range of detailed analyses are planned to comprehensively characterise the drill core, which will provide insights into the geological evolution and mineral systems potential of the region. These results will be released throughout 2021.”

Dr Heap added: “Projects like this reveal the geology underneath the vast sedimentary cover that extends across most of Australia and open up frontier regions for exploration and resource discovery. In the future, the new geological knowledge and methods that we’ve used here can be applied in other similar prospective geological terranes across the country.”

Ian Scrimgeour, Executive Director NT Geological Survey, said the East Tennant NDI drill core provides an exciting opportunity to understand the potential of the underexplored Barkly area.

“The range of ancillary datasets that have been acquired during the drilling campaign, coupled with the ongoing research activities on the drill core, will transform the understanding of minerals systems in the region,” he said.

“NTGS is delighted to provide value-add datasets with the acquisition of hyperspectral data and high-resolution imaging of the drill core through our HyLogger instrument.”

The MinEx Cooperative Research Centre was established to:

• Develop more productive, safer and environmentally friendly drilling methods to discover and drill-out deposits, including coiled tubing drilling technology;
• Develop new technologies for collecting data while drilling, bringing forward mine production; and
• Implement an NDI – a world-first collaboration of geological surveys, researchers and industry that will undertake drilling in under-explored areas of potential mineral wealth in Australia.