Thursday, October 26, 2017
THE INSIDE STORY: Diversified exploration play, Impact Minerals (ASX: IPT) has made a move into the famous Pilbara iron ore region of Western Australia, but this company has a golden gleam in its gaze.
Ever since Paddy Hannan rode into town with saddle bags bursting with gold nuggets, Kalgoorlie and its immediate surrounds have been the hub of Western Australian gold mining.
The region has provided plenty of gold since to keep gold bugs interested, which has left the bulk of the biggest state in the country open to mining of other commodities.
The Pilbara has long been synonymous with iron ore, however there is an emerging group of companies starting to believe it also hosts a wealth of the yellow stuff.
In August, Impact Minerals joined the latest WA gold rush by applying for nine new 100 per cent-owned Exploration Licences in the Pilbara covering 1,300 square kilometres it considers prospective for Witwatersrand-style conglomerate-hosted gold.
The company’s interest was sparked by a review of the Purdy’s Reward discovery in the West Pilbara at base of the geological Fortescue Group by Artemis Resources (ASX: ARV), leading to its Joint Venture with Novo Resources Corporation.
This was followed by the discovery of nuggets and conglomerates in the Central Pilbara by De Grey Mining (ASX: DEG).
The excitement generated from the Artemis/Novo work stemmed from the indication of the possible presence of Witwatersrand-style gold in the Pilbara
For those unfamiliar with the Witwatersrand Basin in South Africa – the region holds the world’s largest known gold reserves and has produced 1.5 billion ounces.
“Although I have been in the industry for a very long time, it’s a little-known fact that I did my PhD on age equivalent basins on the Witwatersrand in South Africa,” Impact Minerals managing director Dr Mike Jones told The Resources Roadhouse.
“So, I’m very familiar with a lot of the history of the Witwatersrand and how it was formed.”
Impact’s new licences cover various parts of the prospective contact between the older Pilbara granite-greenstone terrain and the overlying Fortescue Group rocks in the East Pilbara region including areas close to, and adjoining, licences held by Novo Resources Corporation
Anybody with an extensive knowledge of the Witwatersrand region such as Jones, was sure to take interest in the increasing recognition hitting the market of extensive conglomerate-hosted gold across the entire Pilbara region at several different horizons within the Fortescue Group.
In fact, the interest just served to confirm his, and the company’s, long-held opinion that the area holds much potential for Witwatersrand-style gold.
Of note is that gold in the age equivalent Witwatersrand Basin of South Africa occurs mostly within the middle part of a six-kilometre-thick sedimentary sequence where it mostly occurs as fine to coarse gold associated with carbon seams.
It also produces the region’s characteristic ‘watermelon seed’ nuggets.
“The breakthrough that Nova made was to demonstrate there are a lot of synergies with the Witwatersrand happening in the Fortescue Group basin as it was forming,” Jones said.
‘So, when the announcements came out earlier this year about the shape of the nuggets – the so-called watermelon seed nuggets – that grabbed everybody’s attention, we subsequently pegged all the available ground, which is located mostly in the East Pilbara region.”
The new Impact licences are located in a part of the East Pilbara where gold-bearing conglomerates were first recognised and mined 130 years ago.
This is in the Beatons Creek area where they form part of the Hardy Formation in the lower to middle parts of the Fortescue Group.
“Most people have been focused on the granite greenstones terrain in the area, which is known for its hard rock deposits,” Jones explained.
“Not many people have looked up into the Fortescue area for gold as the conglomerate unit that hosts it is relatively narrow in places and doesn’t look encouraging for traditional gold prospecting activities.
“But you don’t find gold unless you look for it!”
Jones explained that the De Grey results came from the same stratigraphic horizon as Purdy’s Reward below the basalt
“It is 130 kilometres away from Purdy’s Reward in exactly the same position,” he said.
“If you wanted any more proof that this thing has any regional extent – there it is.
“The question is how thick it is and all the other exploration questions that we need to ask.”
Impact Minerals has taken a great deal of encouragement from what it considers to be an overlooked breakthrough made by Novo’s CEO Dr Quinton Hennigh.
Hennigh determined that many of the nuggets in the Witwatersrand may have been sourced from the reworking of gold deposited by microbial activity and basinal fluids early in the history of the sedimentary basin.
According to Jones, this removes the requirement for a source for the nuggets from the underlying granite-greenstone terrain.
“That was one of the criticisms levelled at the potential for these conglomerates to host significant gold,” Jones explained.
“This was an important breakthrough by Dr Hennigh and, once we understood that we acted quickly to acquire the ground.”
Impact currently has a review of previous exploration at the Pilbara gold project underway, from which it will design a program of initial on-ground activities expected to commence in early November under a Miners Right.
Impact has indicated it will be considering options for funding exploration on this new project.
As exciting as the Pilbara gold project could be, the company’s main focus remains its emerging high-grade gold and silver discovery at Commonwealth-Silica Hill 100 kilometres north of Orange in New South Wales.
Impact has continued to produce encouraging results from the Silica Hill prospect.
Recent drilling identified east-west trending structures as an important control of the high-grade zones and shoots within the overall north east trending zone of mineralisation.
It demonstrated the entire vertical extent of the mineralised system has been preserved from an upper barren silica-pyrite zone that passes progressively down and laterally through low grade silver gold veins.
Higher grade gold and silver veins and a lower zinc-lead-copper zone containing ‘feeder veins’ of massive base metal sulphides also have high-grade gold and silver in places.
The most recent results were achieved at Silica Hill, where drill hole CMIPT071 intersected a 30-metre-thick zone of quartz-pyrite-arsenopyrite veins from 83 metres down hole.
This intersection was encountered some 30 metres down plunge from a gold-rich zone the company had identified in previous holes CMIPT063 and 060.
Results from these holes included:
returned 98 metres at 0.7 grams per tonne gold and 53g/t silver from 58m down hole, including 31m at 1.3g/t gold and 70g/t silver from 58m down hole, which included 0.6m at 0.8g/t gold and 2,090g/t silver and 0.2 per cent zinc from 85.4m; and
0.3m at 6.2g/t gold, 149g/t silver, 8.4 per cent zinc, 3.9 per cent lead and 0.2 per cent copper; (feeder vein)
37m at 1g/t gold and 31g/t silver from 51m ending in mineralisation.
“We expect to be back drilling at Commonwealth mid-December,” Jones said.
“We have drilled a lot of holes at Silica Hill already, through which we have learned a lot about the prospect.
“This really is developing into being a major regional system – it’s not just one small lens, it is part of something much bigger.”
Impact Minerals (ASX: IPT)
… The Short Story
26 Richardson Street
West Perth WA 6005
Ph: +61 (8) 6454 6666
Peter Unsworth, Dr Mike Jones, Paul Ingram, Markus Elsasser, Felicity Gooding