In this week’s edition of Bulls N’ Bears Big Hits, we examine some of the notable drill intersections revealed on the ASX, including Mithril Silver and Gold’s stunning hits from its Mexican project that feature 33m at 31.8 grams per tonne gold and 274g/t silver from surface.
We also take a close look at other interesting drill hits from last week as reported by Flynn Gold from its Tasmanian Trafalgar zone and from Patronus Resources’ Cardinia project near Leonora in Western Australia.
So, let’s dive in.
Mithril Silver and Gold
Copalquin District project – Mexico
Hit: 33m at 31.8g/t gold and 274g/t silver from surface
While Mithril’s remarkable drill intercept was featured in Bulls N’ Bears’ regular Runners of the Week column last Friday after it triggered an equally stunning share price run, it was simply too good not to take a second look from a more geological perspective.
The company’s headline hit from its Target 1 area at El Refugio has grabbed its fair share of attention, including the highest-grade intercept drilled to date at the property, with a scintillating 1180g/t-by-metres gold equivalent.
But after the focus on the primary intercept subsided and curious onlookers moved on to absorb the included sub-slices, mouths that were already agape fell to the floor when they saw 7m at 144g/t gold and 1162g/t silver from 18m including a 2m slice running a whopping 495g/t gold and 3765g/t silver from 20m. The final sprinkle of higher-grade precious metals then came in a separate 1m intercept containing 26.9g/t gold and 201g/t silver from 28m.
The headline drillhole is one of five put into the Target 1 area at El Refugio and 900m to the south-east at the historic Copalquin Mine. It was designed to test mineralisation along strike from the historic El Cometa mine on the eastern side of the Target 1 area and where a previous drillhole had intersected 6.8m running a grade of 74g/t gold and 840g/t silver from 35.2m.
The two holes sit in a zone interpreted by core logging and mapping as close to a vertical fault zone cross-cutting the low angle Refugio east-west structure.
Drilling at Cometa is designed to establish its possible vertical and horizontal continuity with Refugio and to better define previously drilled high-grade zones to determine if they are related to near-vertical structures that could be mineralisation feeder systems.
The zone has already been followed up with a second hole drilled along strike that cuts a magmatic breccia over more than 15m and a deeper 30m interval of a hydrothermal breccia, but assays are yet to be received. Three other holes have also been drilled down-dip from the old Refugio mine workings to test an area shallower than the maiden resource model and assays are also awaited.
Mithril managing director and chief executive officer John Skeet says the headline drillhole represents a globally-significant more than 1000g/t gold equivalent-by-metre hit in the area of the company’s maiden Target 1 resource. He adds that in the first quarter of next year, the company hopes to double its existing resource that comprises 2.4 million tonnes at an average grade of 4.8g/t gold and 141g/t silver (6.81g/t gold equivalent) for 373,000 ounces of gold and 10.95 million ounces of silver for a total of 529,000 gold equivalent ounces.
Mithril is exploring Mexico’s Copalquin district, which is located in the country’s Durango State and covers an entire mining district of about 70 square kilometres. It encloses several dozen historic gold and silver mines and workings, 10 of which had notable production.
Additionally, four key hydrothermal cells have been identified within the concession area, with El Refugio exhibiting potential for a doubling of its resource.
The district lies within the vast geological Sierra Madre gold-silver trend that extends north-south along the western side of Mexico and hosts many world-class gold and silver deposits. The deposits originated from multiple epithermal mineralising events where young intrusives are thought to be the heat sources for the mineralising systems.
Mithril has defined at least nine targets in the district, including its current maiden high-grade gold-silver 2021 JORC resource at El Refugio that is supported by a conceptional 2022 underground mining study and relevant metallurgical testwork.
With its district-wide gold and silver occurrences and rapid exploration success, it is clear the Copalquin district has the potential to evolve into another significant gold-silver mining district akin to many others in the Sierra Madre trend – some of which have hosted or currently host between 1 and 5 million ounces of gold along with more than 50 to 100 million ounces of silver.
Flynn Gold
Golden Ridge project – north-east Tasmania
Hit: 3.05m at 4.9g/t gold from 53.1m including 0.35m at 40g/t gold
Flynn scored the headline hit in the second of its first two drillholes put into the Trafalgar North vein zone for a total of 632m in the company’s 100 per cent-owned Golden Ridge project in north-east Tasmania.
The object of the drilling was to test below and along strike from gold hits picked up in recent trenching across several outcropping veins.
The first hole was collared with a dip of -50o to a true azimuth of 140o and ran to a total depth of 473.3m under Trafalgar North and most of the way to deep under the northern margins, but stopping just short of the historic Trafalgar show. It jagged 4.8m at 4g/t gold from 165.6m including 0.4m at 17.9g/t gold from 166.9m and 0.4m at 24g/t gold from 170m.
There is also a separate 0.3m going 25.1g/t gold from 440.5m in a deeply-buried, non-outcropping, steeply-dipping vein that appears to be related to a steep contact on the northern margins deep beneath the old Trafalgar mine.
The second – and headline – hole was collared as a shallow scissor hole directly opposing the first, with a dip of -50o to a true azimuth of 320o to cross the first hole at 95m vertical depth. It successfully transected multiple veins before terminating at 150m downhole depth.
Apart from its featured headline hit, it nailed an additional 2.7m at 4.1g/t gold from 115.4m including 0.35m at 26.6g/t gold at about 100m vertically below the trench.
Flynn kicked off its phase-three diamond core drilling at Trafalgar in mid-April, planning initially to drill about 1500m of infill and extension drilling below and along strike from previously drilled high-grade gold intercepts.
Then in June, the company identified a new zone of gold-mineralisation in surface trenching about 250m north of the historic Trafalgar mine. It pointed to the potential for Trafalgar North to significantly increase the gold footprint of the overall Trafalgar system, thereby making it a new focus of drilling later in the campaign.
In summary, the drilling confirms that the Trafalgar North gold mineralisation disposed through multiple veins, extends from surface to more than 150m vertical depth and remains open in all directions.
Flynn says its drilling has successfully intersected high-grade gold veins beneath the trenched area at Trafalgar North and confirms its interpretation that the Trafalgar zone is continuous at depth and is most likely a parallel zone to the main Trafalgar vein system.
The new vein system at Trafalgar North increases the overall mineralised footprint at the greater Trafalgar location from 300m to 500m width across the granodiorite/sedimentary contact and has potential to host large-scale gold mineralisation.
Patronus Resources
Cardinia East project – Leonora, WA
Hit: 3m at 5.69g/t gold from 77m including 1m at 15.7g/t gold from 78m
Patronus jagged its headline hit in reverse-circulation (RC) drilling at its Cardinia East gold project near the WA town of Leonora.
The program produced significant intercepts from both its Rangoon-Collymore and Cardinia Hill targets and it has now inferred strong potential to grow the East Cardinia mineral resource of 10.4 million tonnes at 1.42g/t gold for 475,000 ounces. The drilling has extended gold mineralisation a further 1.2km to the north along the Rangoon-Collymore trend and a further 250m south of the existing Cardinia Hill resource, with the mineralisation remaining open to the north and south, respectively.
The results highlight further exploration potential within Patronus’ Leonora assets, with the drilling forming part of a bigger resource definition and exploration program that is underway across both the East Cardinia gold project and the Mertondale gold play.
At Rangoon-Collymore, 27 RC holes were drilled at Rangoon for a total of 4312m on 75m-by-200m drill line spacing to test for potential northwards extensions to the existing mineral resource of 2.8 million tonnes at 1.32g/t gold for 121,000 ounces. That drilling was designed to follow-up encouraging air-core (AC) drill results from exploration mid-last year, searching for possible extensions to the Rangoon-Collymore trend.
Results include the headline result from one hole, supported by two other holes that produced 11m at 1.25g/t gold from 58m and 4m going 3.64g/t gold from 26m, respectively.
From the results and also considering previously-reported AC drilling assays, the company says its Rangoon-Collymore trend has been stretched a further 1.2km and now has a defined strike potential of about 4km – in addition to the current 3km strike of the resource trend.
The company also undertook additional drilling at its nearby Cardinia Hill target to explore for potential extensions to the existing resource that comprises 2.2 million tonnes at 1.38g/t gold for 97,000 ounces.
Five RC holes were put in for 804m, with three plugged in south-west of Cardinia Hill to test continuation of the mineralised structures identified in a recent drillhole that returned grades up to 20.5g/t gold. The other two holes tested the south-east extension of the main Cardinia Hill structure along strike, which was previously interpreted to be cut off by an east-west-trending fault.
One hole intersected 3m running 1.3g/t gold from 64m, suggesting that the Cardinia Hill gold-mineralised structure continues at least 250m further south of previous interpretations.
Accordingly, the company is planning further work to follow-up the encouraging result.
Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au
By Doug Bright
