Pic: Schroptschop / E+ via Getty Images
Mining
Special Report: For more than a millennium the Falun copper mine in Sweden played a significant role in meeting the copper needs of continental Europe.
The old mine — now a museum — is thought to have produced as much as two-thirds of European copper needs in medieval times.
Falun is said to have produced 500,000 tonnes of zinc at 5%, 400,000 tonnes of copper at 4%, 160,000 tonnes of lead at 2%, 380,000 tonnes of silver at 35 grams per tonne and 5 tonnes of gold at 4g/t over its life.
While its production days are done, the 1000-year-old mine and its surrounds still holds some secrets.
Alicanto Minerals (ASX:AQI) spent much of 2020 looking to uncover them at the neighbouring Greater Falun copper-gold project it picked up in January last year.
The major exploration techniques used over the area leading up to the time of Falun’s closure had been boulder-tracing – literally following boulder trails, testing the rocks and then trying to determine where they came from relative to the ground beneath.
Alicanto managing director Peter George told Stockhead that the high grade production profile at Falun, the presence of a few small, high grade resources at surface and an extensive trend of high grade grab samples in the area had attracted him to the region, and it was during early fieldwork that AQI started to notice some significant, potentially overlooked signs at Greater Falun.
“While we were out in the field and trying to confirm our theories during the due diligence period, we actually realised we were dealing with a large, limestone mineralised horizon within the area that we kept coming across,” he said.
“That has become very important, mostly because of Erik Lundstam, our chief geologist, and his experience over in Garpenberg (only 40km from Falun), where they made some massive discoveries between the two mines (8 km apart) where they discovered over 130 million tonnes of ore sitting in a limestone mineralised zone since 2000.
“Erik was seeing the same sorts of highly altered and mineralised rocks (as in Garpenberg) when we were out in the field early last year. So we started following those trend lines, picking up more high grade grab samples at surface.
“With smoke everywhere at the Greater Falun Project, a real picture was starting to form for us. After all, where else do you look for a giant high grade orebody but right next door to a known one.”
The maiden exploration program at the start of 2020 then revealed copper-gold skarn mineralisation at Wolf Mountain – the first of its kind to be uncovered in the area.
“When we started to apply the copper-gold skarn and skarn zonation model, as well as factoring in the limestone which is the perfect chemical trap for deposits, we realised we really needed to change our thinking about the project,” George said.
With the re-engineering of the geological model that Alicanto believes has created the mineralisation within the Greater Falun Project, Alicanto set about vectoring in to the driving forces of the mineralisation (the Causative Intrusions) and also confirming the stratigraphic sequence for the project – something it achieved during a 4000m drilling campaign which kicked off in September and is scheduled to be finished next month.
“We have intersected copper-gold and poly-metallic skarn mineralisation in all of the targets we have drilled so far in our most recent 4,000m drilling program,” George said.
“We have also intersected a number of mineralised causative intrustions which are what we believe are the heat-engines for these skarns.
“These current intersections are unlikely to be of economic widths yet, but we need to keep in mind that these areas have never been drilled before and to hit the severely altered rocks and mineralisation we are looking for near surface on the first go in all of the targets is a significant achievement and it really sets us up for our next fully funded drilling program and our search for Falun 2.0.”
Couple that with a $6 million raise late in the year, which will fully fund its next drilling campaign scheduled to follow up the initial 4000m campaign beginning in Q2, and there are exciting times on the cards for the team at Alicanto.
“I think the most important message I can give is that over the last 12 months we’ve done the background work,” George said.
“We’ve done the hard yards out in the field. We’ve visited over 2000 outcrops and historical workings. We understand the rocks, we understand the stratigraphic sequence and where the major orebody for Falun and the mineralisation that we’re actually seeing out in the drilling today sits.
“Now it’s a matter of using that knowledge, combined with modern exploration techniques from the geophysical side and a solid drilling campaign, which we’re fully funded for now – this is the time to find a big orebody.
“As you can imagine, we’re starting to get quite excited about what the next year is going to mean for us.”
This article was developed in collaboration with Alicanto Minerals, a Stockhead advertiser at the time of publishing.
This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.
Mining
Mining
Mining
Get the latest Stockhead news delivered free to your inbox.
