Analysis of the 96km 2D survey has highlighted multiple new caldera structures within the Rylstone Volcanics, comparable to geology that hosts the 396Moz silver equivalent Bowdens Silver deposit.
The Bowdens deposit is the largest undeveloped silver deposit in Australia and the fourth largest in the world – with strong growth potential.
Silver Mines (ASX:SVL) exploration activities will now focus on the five separate calderas modelled – three within the Bowdens Caldera (Bowdens Volcanic Complex), and two within the Coomber Volcanic Complex (including the Coomber Prospect and to the north of Rylstone).
The Bowdens caldera was identified by Silver Mines in August 2022 and the latest seismic survey interpretation comes hot on the heels of positive infill drilling results released last month. These identified strong potential for improved pit design and the conversion of more tonnage and grade mineral resources to ore reserves as Silver Mines works towards an update of its resource and reserve statements, both due in Q3 2024.
MD Jo Battershill said: “The seismic data vastly improves our geological understanding of the Bowdens District and confirms our belief in the potential for the regional exploration.
“The geology team is highly encouraged by these interpretations of the latest seismic surveys as each of those caldera structures could potentially host Bowdens look-alikes or, if closer to the original heat source, copper-gold mineralisation.
“We are now planning targets at Bara Creek, which will involve additional geochemical and geophysics work to be completed over the coming months.
“Ideally, we would like to have drill targets identified well before year end and hope to be drilling before the end of 2024 too.
“It’s a busy but exciting time for us as we finalise the updated resource and reserve statements for release next Quarter, along with compiling all the incoming data and results from the optimisation study.”
A caldera is a large cauldron-like hollow that forms after a volcanic eruption when support for the rock above the magma chamber collapses.
From an exploration point of view, the fluids responsible for metal deposition fill the major structures formed as volcanoes erupt then collapse.
The most prospective areas are along the caldera edge where major ring faults have formed and fluids have been able to flow and cool, depositing mineralisation.
These faults can be the key driver of fluid migration in deposits such as the prolific Round Mountain Gold Deposit in Nevada, the Lihir Gold Deposit in PNG and the Banská Hodruša Gold Deposit in Slovakia.
The Bara Creek caldera is 4km by 4km and has had only limited historical exploration. That was by CRA Exploration in 1989, which identified a gold-copper-silver association in sediment samples.
Also seen as having significant resource potential is the Coomber caldera, which is 3.3km by 3.3km and has silver-zinc-lead-gold mineralisation discovered by CRA Exploration in 1991.
The Armentum caldera is roughly 5.6km by 4.1km and Three Hills caldera is 3.5km by 3.5km. Neither of these has seen any exploration work.
Silver Mines’ regional model is driven by multiple high-quality data sources and industry collaborations, including with the Mineral Systems team at NSW Mining, Exploration and Geoscience, and research through the University of NSW.
This has added to Silver Mines’ extensive and high-quality exploration datasets for the area which have been reviewed to build regional geology models for exploration targeting purposes.
The seismic survey was also conducted as part of Silver Mines’ ongoing R&D project and was awarded $50,000 funding support under the New South Wales Government New Frontiers Exploration Program.
The New Frontiers Exploration Program funding is part of the NSW Government’s Critical Minerals and High-Tech Metals Strategy to promote mineral exploration investment in NSW.
Silver demand is on a strong long-term upward trend as an industrial metal used in clean energy, especially solar panels, as well as EVs and renewable energy storage.
