Todd River Resources has outlined a three-kilometre-long nickel-copper target at its Berkshire Valley project, 150 kilometres north-east of Perth in Western Australia. Recent shallow aircore drilling, designed to test for mineralisation below the soil and alluvium that blankets the region, has consistently returned highly anomalous base metal values kicking as high as 4,800 parts per million copper and 4,000 ppm nickel.
Geological logging has also revealed the presence of a similar package of rocks to those that host the coveted Julimar nickel-PGE discovery, about 100km to the south, hinting that Todd River may be zeroing in on its own discovery in the region.
The company commenced its maiden drilling campaign at Berkshire Valley earlier this year, with aircore drilling testing about 8km of the fertile base and precious metal trend. The program consisted of 300 shallow drill holes, on 400m spaced lines, designed to punch through the soil, sand and gravel cover that masks the signature of the underlying stratigraphy and provide both geological and geochemical samples for analysis.
Interestingly, the program has defined a core target area more than 3km long and 300m wide, displaying precious and base metal mineralisation. Evaluation of the drilling also shows holes only penetrated on average to about 20m below surface but that, importantly, there is evidence of increasing grades of nickel and copper with depth.
The anomaly remains open and untested to the north.
Previous work across the Berkshire Valley hinted at the presence of underlying mafic-ultramafic stratigraphy, however the company’s recent work has confirmed the presence of both gabbro-norite and picrite intrusive units, considered highly prospective for base metal sulphides.
In addition, it appears that when recent shallow drilling did penetrate through the fresh rock interface and into mafic-ultramafic intrusives, sampling consistently returned enriched levels of base metals. Drilling shows high grades of mineralisation, outlining a broad nickel-copper anomaly grading at more than 500ppm nickel and copper.
A significant number of drill holes finished in mineralisation at more than double this grade threshold, suggesting a deeper source for the anomaly.
Todd River’s recent geochemical drilling program is now allowing the company to zero in on deeper targets, with several key areas within the Berkshire trend beginning to tick all the boxes, in terms of their sulphide prospectivity.
The company is now planning infill drilling to better define the key targets in the northern sector of the base metal trend and follow-up reverse circulation and diamond drilling over the deeper anomalies.
Whilst the company’s work program has largely concentrated on the areas of recognised mineralisation in the region, Todd River controls a massive tract of land across this underexplored terrane. The company’s landholding extends over more than 40km of strike, taking in a potential string of buried mafic and ultramafic intrusives that are yet to be tested by modern exploration.
With Todd River ramping up exploration in the region and first-pass auger already completed across the unexplored eastern trend, the market can expect an ongoing stream of results in the weeks ahead as the company looks to uncover a new sulphide system in the hills north of Perth.
Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au
By Matt Birney
