A long-awaited government report into the under-explored Cambrian Stavely Arc in western Victoria, Australia, released on March 2, has vindicated Stavely Minerals Ltd.'s early entry into the volcanic belt and should boost investment in the under-explored region.
The report was the result of Geological Survey of Victoria's and Geoscience Australia's research into the Stavely project, including analysis and interpretation of data collected as part of a pre-competitive stratigraphic drilling program, within the context of other regional data sets.
The two agencies will now start a deep seismic reflection and gravity survey of eastern Victoria this month, which will be the first time that region's geology has been surveyed at great depth.
The Geological Survey of Victoria conducted the most recent surveys of that type in central Victoria in 2006 and western Victoria in 2009.
"[Evidence] suggested that any mineral systems associated with porphyry intrusions would likely be preserved upright, and may also occur outside of the volcanic belts themselves in the intervening panels of Cambrian sedimentary rock," the new report stated.
"This greatly expands the minerals exploration search space in the Stavely Arc," the reported said, adding that its location and development was favorable for a range of arc-related mineral systems such as porphyry, epithermal and volcanic-hosted massive sulfide systems.
Christopher Cairns — managing director of Stavely Minerals, one of only two companies understood to be actively exploring the belt — told S&P Global Market Intelligence that while the new report's contents revealed nothing new, its ramifications for the broader industry would be significant.
"[The report] definitively demonstrates that the Stavely Volcanic Arc is prospective for porphyry copper gold deposits and [volcanic massive sulfide] copper-gold deposits, and that it's under-explored relative to similar sorts of belts in Tasmania and New South Wales," Cairns said.
"The industry didn’t really see the opportunity in this belt, and that is ultimately the significance of this report — the geosurvey did see the potential, and the report synthesizes a whole bunch of work that now stands as a demonstration that the belt is highly prospective.
"Reasonably, the expectation from the government is that it should stimulate exploration in the belt."
While the report was done entirely by Geoscience Australia and the Geological Survey of Victoria, they did ask Stavely Minerals for gravity, magnetics and some geochemistry data sets.
Cairns' company was an early mover into the belt in 2013 on the back of preliminary work by the Geological Survey of Victoria, before listing on the ASX in 2014.
While Stavely Minerals was "already a believer" in the belt, he said the report did provide some clarity for his company's exploration efforts. "The truth is we're looking for a porphyry deposit in a very old belt — we're talking about 500 million years — that's been chopped, sliced and diced by structures," Cairns said.
"When we first went in there we drilled a couple of holes and intercepted some structures that offset the mineralization, and it's taken us a couple of years and quite a lot of head-scratching and technical detailed work to figure out where it went.
"Of late, we’re starting to get drill results that indicate we're getting very close to a porphyry system, and hopefully in a short while we'll get a drill hole into it."
He said the report may also help de-risk the area, and convince the wider exploration community on a technical level. Navarre Minerals Ltd. had tenements around Stavely Minerals until they formed a joint venture and now explore them together.
