By their very nature, drill hits come in all manner of sizes – and from all sorts of terrain and geological structures.
And with prices running wild for a plethora of commodities of late, people and companies are searching all over the place in a bid to turn up the next big market attention-grabber.
This week’s Bulls N’ Bears Big Hits column perfectly explains that theme, with our featured companies peppering holes into nooks and crannies right across this great nation.
From trusty Victorian gold to finds of the precious yellow metal in Tasmania, to rare earths in Western Australia, copper in Queensland and even some heavy mineral sands from the east, this week’s column covers some serious ground.
Let’s dive in.
Southern Cross Gold
Sunday Creek project – Victoria, Australia
Hit: 0.5m at 473 grams per tonne gold equivalent from 913.6m.
Southern Cross caught the attention of the gold bugs early last week with this deep diamond drill hit at its Rising Sun prospect within its 195-square-kilometre Sunday Creek epizonal gold project in the prospective structural Melbourne Zone, about 60km north of Victoria’s capital city.
The hole aimed to test the strike continuity of two high-grade targets in the footwall of the mineralised host rock, drilling along the footwall contact at a high angle to known vein sets. It intercepted seven gold or gold-antimony zones, including three intervals with grades greater than 20g/t gold – including the headline 473g/t gold.
A shallower intercept from 741.9m in the same hole ran 8.7m at 4.1g/t gold equivalent, based on 3.5g/t gold and 0.3 per cent antimony.
Southern Cross has targeted significant vein sets it has defined within 1350m of strike and has tested about 620m of the trend, mainly between its adjacent Rising Sun and Apollo prospects.
The company has put 119 drill holes into Sunday Creek since 2020 for 51,189m. It follows 64 holes for 5599m reportedly drilled between the late 1960s and 2008. The project now contains 38 holes recording hits ranking better than 100g/t gold equivalent by metre intercepts.
Southern Cross says its planned 60,000m of drilling through the year will more than double its existing metreage at the project and it will continue to expand its discoveries through logical step-outs along strike to build tonnage, coupled with a downhole NAVI-drilling program to target high-grade areas.
Farrelly prospect – Victoria, Australia
Hit: 26m at 8.9 per cent total heavy minerals from 6m.
Falcon has come up with some interesting high-grade hits from its 91-hole air-core (AC) drilling program at the company’s Farrelly strandline heavy mineral sands prospect in the Murray Basin in Victoria.
The headline hit calculates to 231m by percentage of total heavy minerals (THM), including 15m at 12.9 per cent THM, or 193m by percentage of THM.
Farrelly lies about 55km west of Victoria’s Murray River border town of Echuca on the south-west margins of the Warranga Western Channel where various companies have explored for heavy mineral sand deposits. The existence of the sands is understood to reflect the ancient shorelines of former inland seas.
By way of overall average grade comparison, Strandline Resources’ Tajiri project in Tanzania contains a JORC-compliant mineral resource of 268 million tonnes at 3.3 per cent THM. Closer to Falcon’s ground, VHM produced a maiden resource estimate of 192 million tonnes at 3.1 per cent THM for its Cannie deposit, 122km north-west of Echuca, in May last year.
Overall, results from Farrelly define a thick continuous zone of high-grade mineral sands in an area measuring about 1200m by 600m. It remains open in several directions and justifies ongoing exploration.
Flynn Gold
Golden Ridge project – north-east Tasmania, Australia
Hit: 0.4m at 67g/t gold within 1.3m at 21.9g/t gold from 248.7m
Flynn burst out of the gates with a good start to its first diamond core program at its Trafalgar prospect at Golden Ridge. Its first hole was drilled to 355.9m, nailing three intercepts at better than 31g/t gold and confirming multiple sub-parallel high-grade gold veins at the prospect.
The 1500m drilling program kicked off mid-last month. It was designed to infill previous wide-spaced drilling and test all three of the main veins (Trafalgar Main, Magazine, and Trafalgar South veins) and associated splays identified in the company’s geological interpretation – including also following up previously-reported high-grade gold results.
The latest of those was prior to Flynn’s tenure when Tamar Gold drilled a 231m diamond hole in 2013 and hit 5m at 12.56g/t gold including 0.4m going 150g/t gold from 202m.
Flynn’s exploration at Golden Ridge has identified anomalous gold on a 9km contact zone along the southern margin of the Golden Ridge granodiorite, which appears to be a big intrusive-related gold system with a string of old workings wrapped around the southern contact of the granite margin.
The Trafalgar Main vein was worked historically by small-scale underground mining for a short period in the late 1800s. The only known production is recorded as about 46 tonnes grading about 137g/t gold.
Browns Range project – East Kimberley region, Western Australia
Hit: 49m at 2.36 per cent total rare earth oxides (TREO) from 540m
Northern Minerals’ latest Wolverine intercept is one of the deepest high-grade rare earths hits seen recently – and unlike the usual pegmatites and clays, it occurs in a different host altogether.
It is also the deepest achieved to date in the company’s mineral resource definition program that targeted down-plunge mineralisation. The hole returned an outstanding 49m run at 2.36 per cent total rare earth oxides (TREO) from 540m and also confirms further extension of the structure and its mineralisation down-plunge.
Additionally, it shows mineralisation remains open at depth and that the mineralised zone appears to be widening with increasing depth. The hole stepped back from its next nearest neighbouring intercept that lies about 60m up-dip, intercepting 13.1m at a grade of 4.35 per cent TREO from 496.9m.
Wolverine’s mineralised zone is a structurally-controlled, hydrothermal system characterised by the mineral xenotime, hosted by a brecciated zone up to 30m wide, trending east-west and dipping steeply to the north.
Xenotime is a rich source of dysprosium and other heavy rare earth oxides (HREO) such as terbium and yttrium. Wolverine contains a high HREO-to-TREO ratio where about 89 per cent of the TREO is medium to heavy rare earths.
Dysprosium and terbium are essential to the production of the neodymium-iron-boron magnets used in clean energy, military and high technology solutions.
The drilling campaign is being co-funded through a grant awarded as part of the Federal Government’s Critical Minerals Development Program. The goal of the program was to achieve 66 pierce points through the structure at a 25m grid spacing for about 18,000m of drilling.
The latest assays bring the total intercepts to 39 and the results will inform an updated mineral resource estimate for Browns Range, with the goal of upgrading most of Wolverine’s current inferred resource into the indicated category.
Austral Resources
Flying Horse-Lady Annie operations – Queensland, Australia
Hit: 40m at 2.27 per cent copper from 132m
Austral, an Australian copper producer, revealed last week that assays from its current diamond drilling – part of its scoping study into the company’s Flying Horse deposit – highlight a 40m intercept in sulphides running a grade of 2.27 per cent copper from 132m, including 16m going 4.71 per cent from 150m.
The company bought the Lady Annie operations, along with all tenure and assets from its predecessor CST Minerals in July 2019. Lady Annie has been an operational copper mine for more than a decade and all eight deposits within the operation are secured by granted mining leases.
Historically, it has produced up to 30,000 tonnes per year of copper cathode from four open pits, which include Lady Annie, Lady Brenda, Mount Clarke and Flying Horse. The Flying Horse, Mt Clarke and Mt Kelly open pits lie just 1.6km from the company’s copper oxide processing facilities and about 120km along a sealed road from the major mining town of Mount Isa.
The Flying Horse pit is one of three mines developed on a cluster of mining leases during the early 2000s. Large-scale production of copper oxide ores began in 2005 and delivered more than 55,000 tonnes of copper during the life-of-mine. Copper mineralisation is believed to be controlled by combined structural controls and chemical interactions similar to those prevailing in most sedimentary-hosted copper deposits globally.
Management says the latest results from the Flying Horse drilling has improved its structural understanding of the Flying Horse-Mt. Kelly-Mt Clarke systems and provide further scope for future copper exploration. The results also highlight extensions to known high-grade copper mineralisation and confirm the exploration potential of Austral’s ground for both copper oxide and sulphide mineralisation.
Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au
