A technical review of Octava Minerals’ Talga project in Western Australia’s Pilbara region has revealed fractionation typical of lithium-caesium-tantalum (LCT) pegmatites and stellar gold grades in soil samples of up to 5.45 grams per tonne.
The company says the study, conducted by renowned exploration consultants CSA Global, has uncovered a previously unrecognised target zone for pegmatites of more than 100 square kilometres to the north of the Mt Edgar batholith. It says the prospectivity of the project is further supported by strong lithium-in-soil values from a sampling program that identified an anomalous zone extending to about 1km in length.
CSA’s key findings indicate that the lithium-bearing pegmatites at Octava’s Pinnacle Well and Nimerry prospects originated from a unit called the Munganbrina Monzogranite, within the Mt Edgar batholith. Portable x-ray fluorescence (pXRF) results at Nimerry have shown the pegmatites are likely to be part of the fractionated LCT pegmatite group.
The company now believes exploration efforts need to be concentrated some 2km to 8km away from the monzogranite, within the greenstone belt where higher lithium enrichment would be expected.
The Talga project is made up of a group of seven adjacent tenements in WA’s East Pilbara region, about 30km north-east of Marble Bar and is highly prospective for gold and lithium – especially given its proximity to notable neighbours including Global Lithium Resources and Calidus Resources.
It lies in the highly-prospective north-eastern portion of the Marble Bar greenstone belt dominated by folded and structurally-deformed greenstones.
Since Octava’s listing on the ASX boards just over a year ago, it says it has undertaken a systematic approach to lithium exploration at Talga, which has included the identification of outcropping pegmatites at its Pinnacle Well and Nimerry prospects.
At Pinnacle Well, in the southern part of the tenements, a previous rock chip sample returning 0.22 per cent lithium oxide indicated the prospectivity of the area. But only minimal lithium exploration had been recorded previously, despite its similar geological setting to Global Lithium’s Archer deposit that has a hulking resource of 18 million tonnes at 1 per cent lithium oxide.
Talga is just 10km north of that bonanza deposit and Octava has now put its stamp on a 1.5km-long, east-west-trending pegmatite where newly-recorded pegmatites show lithium results of between 100 parts per million and 203ppm.
Octava’s maiden drilling program at Pinnacle Well totalled 725m in the anomalous zone. The company reported two notable intersections with results of up to 4m at 667ppm, which it intends to follow up.
The newly-defined Nimerry sits just 3km to the east of Pinnacle Well. It has pegmatite outcrops of up to 30m in width and more than 60m in length and rock chip assays have recorded peak lithium values of up to 716ppm.
With lithium fervour everywhere, one could be forgiven for forgetting the “old faithful” called gold. But this area is a regal target zone for the precious metal and is only some 10km north-east of lavish ground known as “Talga Talga”, which Talga Gold floated off in 2010.
Occurring in what appears to be along the major arcuate trend from Talga Talga, gold results from soils have revealed striking grades of 5.45g/t gold and the company has now delineated a 400m-by-40m zone adjacent and to the north of its Razorback gold prospect.
Razorback has recorded a host of significant gold intersections from previous drilling with only 700m of a 4km strike of siliceous chert having been tested to date. Previous geophysical testwork has indicated six high-priority targets which the company considers a priority for follow-up drill testing.
Investors should now wait with a keen eye for further exploration once Octava progresses its heritage agreements with traditional landowners at Talga. The area has emerged as a lithium door-opener in an otherwise gold fever district.
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By Lisa Wells
