Chariot Corporation has struck some intriguing mineralisation during exploration at its Black Mountain project in the United States, suggesting it may be homing in on a high-grade lithium source, which early evidence suggests may be lurking beneath.
The company has confirmed the presence of rubidium in feldspar crystals, which is often a pathfinder to lithium-caesium-tantalum (LCT) mineralisation, with high ratios of potassium-to-rubidium being a further source of encouragement. The latest findings have driven management to shift its primary lithium exploration focus to the site in the US State of Wyoming.
According to Environmental Resources Management (ERM), which Chariot has engaged as a local authority for advice, the early findings are worth pursuing. ERM says given the potassium-to-rubidium radios – which are running under 30 (a standard considered a key indicator for LCT mineralisation), Chariot’s early targeting looks promising.
The company now has its ears pinned back in the hunt for what could be a significant and new, North American lithium discovery.
As an added demonstration of the method’s effectiveness, Chariot defined a “fractionation trend” within its ground where fractionation increases towards the south and exhibits K:Rb ratios averaging 24. It contrasts with the northern suite of samples, which averaged K:Rb ratios of 47 in the same dataset.
The southern cluster is also associated with high-grade lithium mineralisation noted at surface and in drillholes and shows the sampled pegmatites to be all of the high-fertility LCT-type. The trend coincides with an increase in the number and degree of moderate to highly-fractionated LCT pegmatites in the central and southern pegmatite clusters compared to the northern cluster at the Black Mountain project.
The graphical plot of K:Rb ratios also instantly highlights the fertility variation between samples in the northern, central and southern clusters of pegmatite samples.
Management says it employed a portable x-ray fluorescence (pXRF) instrument in the field to test its 218 potassium-feldspar samples that were taken from outcropping pegmatites at the project. The sampling of potassium-feldspar to determine the level of fractionation in pegmatites is a well-established technique used to assess the lithium prospectivity of LCT pegmatites.
The company found that most of the southern samples delivered high LCT values, reinforcing the high-fertility conclusion emanating from its work on the K:Rb ratios.
Chariot says it is already conducting potassium-feldspar sampling at its Copper Mountain and South Pass projects, also in Wyoming, and it plans to roll out the method at its other pegmatite projects across the US.
Management is now also looking at probing the southern suite of pegmatites at Black Mountain with a drill rig in a bid to establish the ultimate proof of its new approach.
Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au
By Doug Bright
