The first results from C29 Metals Ltd (ASX:C29)’s maiden drill hole at the Pocitos 7 Lithium Brine Project on Pocitos Salar in the province of Salta, Argentina, are in with the company describing them as "meaningful".
In February, the company completed its first diamond drill hole at the project, which it drilled to 420 metres with packer tests intercepting a deep aquifer from 370 to 400 metres.
A flow test was conducted through a 49-millimetre pipe with a submersible pump and achieved its maximum pumping rate of 2,000 litres an hour.
Up to 142 ppm lithium
The average grade of three-packer assay results was 129 parts per million (ppm) lithium, consistent with peers operating in the salar, with a maximum assay of 142 ppm lithium.
C29 says the results indicate a trend that lithium is concentrating at the 400-metre depth level above a clay layer with low porosity, and that field density measurements indicate brine grade will increase towards the centre of the exploration licence.
SGS Laboratories returned these results, which have been confirmed by the second set of samples sent to Alex Stewart Jujuy Laboratory.
In analysing the results, the company’s technical team noted a lower-than-expected density or specific gravity in the lithium-charged brine samples indicating the likely influence of freshwater recharge.
The specific gravity of a brine sample is a function of a number of factors including the local porosity of sediments (clays), the impact of subterranean fresh-water recharge, and the chemistry that contributes to an increase in specific gravity.
Hydrological features
The company’s technical team believes that the presence of hydrological features on the eastern flank of the licence has resulted in local freshwater recharge causing the reduced specific gravity.
The next step for the project is to undertake a magnetotellurics (MT) geophysical survey to locate the most prospective position for the next hole.
Existing available geophysical data has penetrated only to depths of around 250 metres and an MT survey will allow mapping of geologic structures to depths of at least 500 metres.
The company expects to conduct an MT survey at both of Pocitos 7 and Pocitos 9 – a licence some 2.6 kilometres to the south of Pocitos 7.
Meaningful concentrations
Director Jeremy King said: “We are very pleased with the results at our first hole at Pocitos 7 which has established the presence of lithium in meaningful concentrations in a project in the heart of the Lithium Triangle.
“We look forward to receiving the Ekosolve pilot plant test-work which we believe will demonstrate the potential viability of this project.
“The technical team will continue to advance the project with geophysics and drilling to a point where we can deliver an indicated and measured resource.”
Ekosolve™ DLE technology test-work at the University of Melbourne is now underway.
A deeper MT geophysics program will be conducted to guide the next drilling location.