Novo to probe ancient 1km-wide Sholl Shear in West Pilbara

Novo Resources is set to kick off a maiden air core drilling program before month’s end to test a promising part of the Sholl Shear within its Balla Balla gold project in Western Australia’s West Pilbara region. 

The program will target structurally complex zones along and near the Sholl Shear, an ancient fertile structure running parallel to and about 10 kilometres inland from the WA coastline for more than 200km. The Balla Balla project is centred about 80km southwest of Port Hedland.

Novo and its joint venture partner, Chilean-based, United States-listed explorer Sociedad Quimica y Minera de Chile SA (SQM), hold interests in three contiguous exploration licences across the Balla Balla tenure. A fourth granted exploration licence covers ground 9km east of the main trio of licences, 2km south of the Sholl Shear.   

The emerging exploration venture is in a geologically interesting area that has four main fault or shear zones running through it that make it ripe for exploration. 

Balla Balla straddles part of the Sholl Shear and its related prospective structural corridors. Novo has identified several prospects along a 10km trend, including some that lie beneath relatively shallow cover. A 28km section of the shear runs exclusively through the SQM-Novo joint venture component of the tenement group.

Historic drilling indicates the recent surface cover across the targeted areas would likely not exceed 25m depth. As a result, air core drilling is expected to be well-suited to penetrating the unconsolidated cover.

Air core drilling will enable fast and economical access to any stable buried soil or lateritic profiles that may carry useful geochemical signatures, along with bottom-of-hole geology and geochemistry data.

The Sholl Shear runs parallel to the coastal and nearby continental margin and was formed by the tectonic collision of two geological domains about 3 billion years ago. 

Major shear zones and faulted contacts between varying rock units often host mineralisation - and the West Pilbara is no exception.

The variety of structural features associated with the Sholl structure provide multiple plumbing systems for mineralising fluids and deposition sites for a wide range of minerals and metals, including gold. 

The Sholl shear and the north-northeast trending 140km-long Loudens Fault transect the Novo-SQM joint venture ground at Balla Balla.

The western end of a third, east-west trending mineralised shear zone - the Mallina shear zone - terminates against the Louden Fault, 45km south of Novo’s ground. The eastern end of the Mallina’s shear passes less than 5km north of De Grey’s 12.7-million-ounce Hemi project.

The Hemi discovery is an intrusion-hosted form of gold mineralisation new to the Pilbara and exhibits a scale of mineralisation not previously seen in the Mallina Basin. The discovery is hosted in a series of intrusions associated with stringer and disseminated sulphide-rich zones.

A fourth fault zone, the 75-km southwest-northeast trending Wohler Fault, bridges  the Loudens and Mallina faults, ending 15km west of Hemi.  Wohler’s western end terminates at Loudens Fault, 15km south of Balla Balla. 

The overall regional setting involving the Sholl Shear zone and its genetic and structural antecedents, coupled with the region’s proven copper and gold fertility, all point to the high level of mineral potential in and around the shear. 

Novo has completed all of the compliance procedures and applications required before launching its proposed first-pass air core drilling program. 

The company executed an Aboriginal heritage protection agreement with the Kariyarra Aboriginal Corporation (KAC) in November last year so that the principal joint venture licence application could be granted. 

It completed a site avoidance heritage survey with KAC and the Department of Energy, Mines, Industry Regulation and Safety late last year approved Novo’s program of work for the Balla Balla project.

Novo’s upcoming drilling program will test the prospect’s first key targets, Ramquarry, Beaufort, Babbage and Cockerells, which were selected largely on geophysical grounds, combined with available historical drilling results.

The company will run out its air core lines at a nominal 640m spacing with holes centred at 50m. The drill holes will be orientated at 140 degrees to ensure optimal coverage to test northeast-southwest striking target structures, consistent with the overall stratigraphic trend. 

Holes will be drilled to blade refusal within the limits of penetration capability of the drill rig to obtain bedrock geological information and a stick of core will be collected from the end of hole for record retention and analysis.

Subject to weather, Novo plans to hit the “go” button later this month.

Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au