In this week’s edition of Bulls N’ Bears Big Hits, we examine some of the notable drill intersections revealed on the ASX, including Santana Minerals’ spectacular intercept of 41.6m at 8.6 grams per tonne gold from 164.4m.
We also take a close look at other interesting drill hits from last week as reported by Lightning Minerals in Western Australia and Winsome Resources at its Adina project in Quebec.
One for lithium and two for gold – one of them a cracker and the other a geological prediction for big things in the future.
So, let’s dive in.
Santana Minerals
Bendigo-Ophir project – Otago, New Zealand
Hit: 41.6m at 8.6g/t gold from 164.4m
We wrote on Santana in this column last month, but it’s hard to go past the unfolding events at its Bendigo-Ophir project – arguably the most significant single gold deposit in New Zealand in more than four decades and potentially transformational for the company and the country.
Every time Santana drills at its Rise and Shine (RAS) target, it seems to reveal another boomer and this hit is no exception. It is almost as if RAS was somehow inspired to do better than last month’s findings in two diamond holes that bored through 41.8m going 5.8g/t gold from 167.3m and 39.5m running 5.1g/t gold from 167.5m.
The two earlier holes are part of a seven-hole program probing the core of the deposit in a bid to verify the continuity of previous high-grade results and ensure appropriate lateral and vertical projections of the grades during resource modelling. The next closest intercept, about 17m up-dip from the headline hit – centre-to-centre and on the same section – also runs a healthy 42.1m at 4.3g/t gold.
And its other neighbour, about 25m down-dip, grabbed 29.3m at an impressive 14g/t gold from 165.8m, just a miner’s nose-hair less than half an ounce of gold per tonne.
It is also worth mentioning that the next hole, just 45m up-dip, gives the entire section an imprimatur of worthiness with its 52.8m at 2.4g/t gold from 174.2m depth and a separate deeper intercept of 21m going 2.6g/t from 236m.
The upshot of all the golden goodness is that while the object of the seven-hole infill validation campaign was to check out the potential for resource over-estimation through over-extension of high-grade zones during resource modelling, it has actually succeeded in demonstrating remarkable grade consistency and structural continuity.
Santana says the proportion of gold in the zone, which has been drilled to about 25m hole spacings, is extraordinarily high and the area is actually bigger and more continuous than previously thought. It says the better-defined high-grade core of the RAS deposit will now form the foundation of the early production planning for its future mine.
The company says it is now resuming its original focus on resource definition drilling at its Come-in-Time satellite deposit in a bid to upgrade it to a JORC-compliant indicated resource and include it in the imminent mine optimisations and planning. It remains focused on completion of its maiden PFS in the December quarter.
Lightning Minerals
Mailman Hill project – 30km east of Leonora in WA’s Goldfields-Esperance region.
Hit: 141 parts per billion gold at 1.5m.
Readers may well ask, “Is that a typo? A 141ppb gold big hit?
While this is not one of our usual headline-grabbing boomers, “big hits” are all relative.
And in the realm of exploration geochemistry, significant geochemical results – regardless of absolute values and grades – are all about statistical anomalism that may unveil a new exploration target standing out from the usual background values. Put simply, the technical detail surrounding this particular intersection may just position it as a pre-emptive “big hit” for the future.
It comes from Lightning’s recent shallow auger drill sampling program at Mailman Hill, which comprises a single 101.8-square-kilometre granted exploration licence. The program was a logical early-stage, fast and relatively low-cost reconnaissance play to identify new exploration targets that might extend south-eastwards from Cavalier Resources’ adjacent Crawford gold project.
Crawford sits a mere 600m north-west of the northern boundary of Lightning’s exploration licence. It hosts an inferred and indicated 3.75 million tonnes at 1g/t for 118,000 ounces of gold and an initial probable ore reserve of 1 million tonnes at 0.91g/t gold for 29,000 ounces.
The contiguous Crawford tenement wraps around the north-west corner of Lightning’s ground and the greenstone host to the deposit, which is easily seen in aeromagnetic data. It extends south-eastwards into and through more than 8km of Lightning’s ground.
The company’s auger geochemical survey tested that 8km block of prospective geology which, along with Crawford, lies within the prospective Keith-Kilkenny tectonic zone (KKTZ) – a major structural feature in the Eastern Goldfields that has a strong association with various gold deposits in the region.
An auger drilling grid was established perpendicular to the strike of the greenstones, from Mailman Hill’s north-west corner, then south-east across almost the full width of the northern part of the licence, where the mostly buried greenstones are highlighted prominently in the magnetics.
Drillhole depths were mostly 1.5m, but range between 1m and a maximum of 6m.
Surprisingly, the peak gold response of 141ppb was identified not where it might have been expected – along strike from Crawford – but in ‘Target Area Two”, which lies 3km east of the most obvious line of south-eastwards strike from Crawford. Although the program picked up only modest responses in sample lines close to Cavalier’s deposit, they almost certainly indicate a likely Crawford extension into Lightning’s ground.
A 141ppb gold anomaly might not look like much, but many deposits have been borne out of lesser anomalies. And as an object lesson in geochemistry, this space is well worth watching to see how it develops.
Winsome Resources
Adina project – Quebec, Canada
Hit: 15.3m at 3.30 per cent lithium oxide from 179.2m
Drilling results show that shallow, high-grade mineralisation in the Adina lithium project in the Eeyou Istchee James Bay region of Quebec, extends along the entire 3km strike length from the west of Adina Main through to Adina East.
Encouragingly, most of the results arise from drilling at Adina SW, Adina East, Ridge and other exploration targets areas outside the mineralisation within Winsome’s latest mineral resource estimate envelope. Adina’s deposit comprises two distinct stacked sigmoidal pegmatite lenses separated by between 110m and 170m of enclosing host rock that lies flat near surface before diving off to the south-east at about 40o toward the project boundary.
The company’s resource estimate was released in the second quarter of the year, revealing the deposit contained 77.8 million tonnes at 1.15 per cent lithium oxide, representing a 33 per cent increase over its previous estimate and with 79 per cent in the indicated resource category.
While most of the recent drilling focused on obtaining geotechnical, hydrological and metallurgical data to support the company’s current and future project works for Adina, it also served to test interpreted extensions to mineralisation hinted at in the normal course of resource definition drilling, or the geotechnical work.
The latest results originate from 40 drillholes put into the Adina for 13,080m of drilling, most of which was in the June quarter as part of Winsome’s exploration and sterilisation drilling. The headline hit was accompanied by several other worthwhile intersections including 17.3m at 1.8 per cent lithium oxide from 302.5m and 16m at 2.15 per cent lithium oxide from 82.3m.
Other more notable grabs included 15.3m at 1.35 per cent lithium oxide from 38.3m and 6.8m at 1.84 per cent lithium oxide from 60m which came with a second intercept of 8.3m at 1.5 per cent lithium oxide from 237.6m.
Management says its latest drilling results from Adina show that shallow, high-grade mineralisation extends along the entire strike distance from the west of the deposit, all the way through to Adina East and remains open to the east. The company has found that intersections in the more distant easterly holes of the property contain some of the best of the recent intercepts and offer further encouragement to undertake more drilling at Adina East.
The company’s improved understanding of the geology and its potential has prompted a drilling re-direction to test the continuity and grade of mineralisation outside the current mineral resource estimate, along the entire 3.1km of mineralisation defined in the Adina drilling to date. That work will be undertaken in parallel with on ground activities to identify and advance new targets for drilling in the forthcoming winter season.
The key takeaway in this Big Hits context is that, as so often happens, the process of completing a mineral resource estimate and putting a nice bow on it is often also the time when resource infill, extension and “pre-mine” drilling is taking place to sort out final remaining questions and starts picking up additional resources.
Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au
By Doug Bright
