Phase one drilling at Chariot Corporation’s Black Mountain hard rock lithium project in Wyoming has wrapped up, with all holes hitting highly-fractionated pegmatites and high grades expected to soon emerge.
The company says it unveiled grades as high as 1.12 per cent lithium oxide in the first three holes, with the last six only going to 0.2 per cent. But buoyed by the fractionated nature of the lower-grade rocks, management is prepping the drill bit for phase two efforts.
Since kicking off the phase one drilling program at Black Mountain in November last year, Chariot says it has come across outcropping pegmatites during field work and diamond drilling assays have revealed high-grade intercepts of between 0.8 per cent and 1.12 per cent lithium oxide in intervals of more than 14m. The best of the phase one intercepts went 15.48m at 1.12 per cent lithium oxide and 79 parts per million tantalum pentoxide from near surface at just 2.74m.
Even though the grades in last six holes in the program are not high – typically between 0.1 per cent and 0.2 per cent lithium oxide – the thickness of rock containing pegmatite dykes is respectable at anywhere between 40m and 85m. Chariot says it is excited by geochemical results, suggesting they put it in the right postcode for a fertile lithium-bearing pegmatite system.
Even more significantly, the lower-grade pegmatites indicated that they could be the edges of a higher-grade, lithium-rich feature. The geochemical data in soil sampling at Black Mountain also supports the theory, with lower lithium samples showing a high degree of fractionation.
Management says it interprets the highly-fractionated, low-grade pegmatites to represent individual offshoots, or in some cases, zones of larger spodumene-bearing pegmatites – and that will be ground-truthed through further drilling during a phase two diamond hole program.
Chariot says its phase one drilling efforts were restricted to a two-hectare postage stamp of ground, limiting its drilling to just the east of the project area. It now has plans to step out of that area with a heavily-liberalised disturbance limit after applying for a massive 1012ha chunk of ground under an exploration plan of operations (EPO) that will clear the way for phase two drilling, following the completion of cultural and archaeological studies.
The company says phase two will likely involve another 2000m to 3000m of diamond drilling, which it plans to launch later this year after EPO approval. Between now and then, it will consider the economics of chasing the pegmatite stocks from existing drill pads.
Magnetic data suggests the huge pegmatite stocks, which feed the pegmatites seen at surface, are associated with a large magnetic low at depths of 100m or more. The surface expressions graded as high as 5.35 per cent lithium oxide in rock chips, giving even more support Chariot’s hunt for the source.
Management says it now owns seven hard rock lithium projects comprising 795 claims for a total area of 6270ha in Wyoming, all within an 85km radius, with Black Mountain now being the biggest area by 936ha.
Wyoming is a tier-one mining jurisdiction where production contributes to more than 20 per cent of the State’s gross domestic product (GDP) and it is the biggest oil and gas producer in the United States – boasting oilfield and other related services capable of supporting the company’s exploration plans.
The devil is in the detail with lithium systems and understanding where drillholes sit in the big picture is key. Although Chariot’s last six holes threw up lower grades than expected, the results allow its geologists to further refine their model for Black Mountain.
With more drilling on the horizon, this will be one to watch during the last half of the year.
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By Andrew Duffy
