In this week’s edition of Bulls N’ Bears Big Hits, we examine some of the more notable drill intersections revealed on the ASX, including Astute Metals’ 59.43m at 1300 parts per million lithium from 73.2m. We also take a close look at other interesting drill hits revealed last week by Patagonia Lithium, Australian Rare Earths and FireFly Metals.
Is the widely-predicted third lithium wave finally ready to roll into the world’s investment market shores?
Well, if a recent prediction from the UN Trade and Development (UNCTAD) is anything to go by, punters may soon have a need to slip on their boardies or bikinis. The group established by the UN’s General Assembly way back in 1964 forecast, after assessing new numbers put out by the International Energy Agency (IEA), that lithium demand could rise by more than a whopping 1500 per cent between now and 2050.
And if net-zero emission goals are to be achieved by 2030, UNCTAD believes the lithium mining industry will require up to 70 new mines.
So, we will start this week’s column looking at a decent lithium hit by Astute Metals.
Let’s dive in.
Astute Metals
Red Mountain project – Nevada
Hit: 59.43m at 1300ppm lithium from 73.2m
In a classic example of how we might wish our exploration would progress from grass roots, Astute Metals nailed 59.43m at 1300ppm lithium in the first hole of its maiden drilling at Red Mountain.
The company says results from its first three reverse-circulation (RC) scout holes along more than 4.6km of strike indicate it may just have made a major new lithium discovery. The second hole intercepted 15.2m at 810ppm lithium from 15.2m and the third hole hit two runs – 6.1m at 1050ppm from surface and 12.2m at 1060ppm from 18.3m.
The program entailed 11 RC holes for 1518m of drilling to test broad coherent lithium anomalies from the company’s soil geochemical and rock chip sampling late last year and to outline the extents and grade potential of the mineralisation.
Astute pegged the Red Mountain ground late last year, specifically targeting the Miocene-age Horse Camp Formation (from about 23 to 5.3 million years old), which is more than 2500m thick and includes a diverse suite of lake sediments known to host big lithium deposits in Nevada.
The deposits include Lithium Americas’ 16.1 million-tonne lithium carbonate equivalent (LCE) Thacker Pass project, American Battery Technology’s 15.8 million-tonne LCE Tonopah Flats deposit and American Lithium’s 9.79 million-tonne LCE TLC Lithium project.
In September, Astute undertook an 819-point soil sampling campaign on a 400m-by-100m grid across prospective host rocks, reporting in mid-November that results revealed strong lithium anomalism in soils, with grades up to 1110ppm lithium and a coherent anomaly of more than 50ppm lithium extending through an area measuring about 8km along a north-south strike and up to 2.8km wide.
By late November, the company had completed a 36-sample follow-up rock chip campaign to test for lithium at strategic locations and across a range of outcropping and shallow sub-cropping rock types.
The rock chips confirmed the presence of lithium-mineralised claystone, with 10 samples averaging 1102ppm from grades in the range of 132ppm to 2190ppm.
Astute’s maiden drilling kicked off in May. From grass roots to major discovery in a mere nine months would really be something quite special.
Patagonia Lithium
Formentera project – Argentina
Hit: 580ppm to 591ppm lithium (metal) and total aquifer porosities up to 47 per cent.
Patagonia Lithium’s drilling at its flagship Formentera project in northern Argentina has produced some unusual “big hits”. But their significance deserves airing, mainly because it is another example of a few short steps between grass roots whiffs of mineralisation to a potential boomer of a project.
Based on a confirmatory geophysical survey and a handful of preliminary shallow geochemical brine samples from the Formentera salar last year, which produced three samples assaying 1008ppm, 467ppm and 238ppm lithium, Patagonia lined up a 10-hole program at the project for up to 3000m of drilling. The first well was completed to a depth of 370m in early April, while a second well, collared about 330m south of the first, was completed at 347m in late May.
Both wells were subject to brine analyses and density measurements, flow rates, resistivity, conductivity, resistivity and porosity testing.
The holes achieved remarkably similar and directly comparable results, encountering ideal permeable host lithologies comprising deep porous sands between 80m and 200m deep and gravel units in aquifers described by the company as “sensational for pumping brines”.
Porosity tests demonstrated upwards of 27 per cent and as high as a jaw-dropping 47 per cent total porosity in parts of their aquifers up to at least 200m in depth.
Brine analyses from the first hole revealed outstanding lithium values, including between 580ppm to 591ppm at densities of 1.186 grams per cubic centimetre from two laboratories from a 21.7m-thick aquifer and more than 235ppm lithium in an aquifer interval from 170m to 370m. Analyses from the second hole reported between 580ppm and 582ppm lithium from two labs, with both recording the same brine density of 1.189g/cc.
Importantly, brine densities in both holes increase progressively with depth, an important indicator of increasing total solute concentration.
Patagonia’s first two wells at Formentera indicate a robust and likely common aquifer with exceptional porosity and hence flow rates, negligible short-term aquifer draw-down, consistent brine density profiles and excellent lithium assays. The company’s latest results give it encouragement that it could be sitting on a big, world-class lithium brine resource.
Koppamurra project – Mount Gambia, South Australia
Hit: 1889ppm total rare earth oxides (TREO) from hand-auger drilling.
In yet another intriguing “grass roots” story, a regional, shallow hand-auger scout drilling program by Australian Rare Earths has identified rare earths mineralisation in two unexplored exploration licences about 60km south of the company’s existing Koppamurra resource near Mount Gambier in South Australia.
Koppamurra’s resource includes 186 million tonnes at 712ppm TREO. The company’s latest program picked up a top hit of 1889ppm TREO at 0.7m below surface, with a combined 27.6 per cent neodymium-praseodymium (NdPr) light magnet rare earths component and 3.1 per cent dysprosium heavy magnet rare earths.
The magnet sub-components of the TREO assemblage are sought after for their application in the manufacture of long-lasting and heat-resistant “permanent magnets” that are employed in high-performance electric motors and modern power-generating turbines.
The next five best TREO hits range in grade from a low of 1147ppm TREO to a second-highest grade of 1654ppm. In those five next-best hits, the combined proportions of NdPr ranged from a low of 20.5 per cent to 24.7 per cent and from 2.2 per cent to 4 per cent for dysprosium.
The company says the overall TREO grades and the separate mineral assemblages are comparable to those encountered in its Koppamurra resource area.
The auger drilling program was designed as a mobile, fast and low-cost scout program to evaluate potentially-mineralised clay horizons known to exist at shallow depths. It comprised 1047 samples from an average depth of 1.1m, with 371 samples being sent for analysis.
Management says that while 70 per cent of the holes intersected clays, mainly in the southern licence, other areas where sampling did not intersect mineralised clays should still be considered prospective for deeper clays below the reach of the auger.
Green Bay project – Canada
Hit 1: 26m at 8.2 per cent copper equivalent.
Hit 2: 55m at 1.8 per cent copper equivalent.
Firefly Metals’ drilling at Green Bay has continued to produce consistent high-grade copper-gold mineralisation, which it has shown to extend to 460m outside the current lower resource boundary.
Somewhat unusually, the project hosts two distinct styles of copper mineralisation, the first of which is a high-grade copper-gold massive sulphide zone (VMS), while the second comprises a large-scale, copper-rich footwall zone (FWZ). The two principal estimated mineral resource areas at Green Bay are the Ming deposit and the Little Deer Complex. The Ming underground deposit features both VMS and FWZ mineralisation styles.
Following the acquisition of Green Bay, FireFly restarted drilling at the Ming underground in October last year. A month later, it began a 1500m underground drill drive from which step-back drilling could be conducted to explore for down-plunge extensions of mineralisation below the current resource.
It put in 48 holes for 20,824m of diamond drill core from underground development positions into locations outside and below the current resource limits.
The headline 26m hit, which includes 13.1m at 14.3 per cent copper equivalent (10.7 per cent copper and 4.1g/t gold) relates to one of the step-back holes drilled from the development drive into to the upper, high-grade VMS zone that sits just outside and just below the current resource.
Similarly, the nearby secondary headline hit of 55m at 1.8 per cent copper equivalent, including 12.1m at 2.3 per cent and 8.9m at 3 per cent, relates to one of the step-back holes put into the FWZ from the development drive, also just below and outside below the current resource.
The deepest 460m step-back hole to date yielded intercepts including 6.3m at 5.9 per cent copper equivalent in the VMS and 102m going 1.7 per cent in the FWZ.
Both headline intercepts and other nearby high-grade intercepts from the same development drive drill sites demonstrate a high probability that high-grade VMS and FWZ mineralisation continues down-plunge to at least as far as the deepest hole.
FireFly says the latest results will be incorporated into its next resource upgrade. Its resource stands at a measured, indicated and inferred 39.2 million tonnes at 1.83 per cent copper, 0.3g/t gold and 2.7g/t silver for a total metal content of 718,000 tonnes of copper, 370,000 ounces of gold and 3.41 million ounces of silver.
The company says it is planning a 1200m phase two extension to the phase one drill drive, from which it plans a further 60,000 of drilling to test even deeper extensions of the VMS and FWZ zones.
Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au
