VIDEO: VMS deposits present exciting new zinc-copper-gold discovery opportunities in Mexico

Volcanogenic massive sulphide (VMS) deposits have been a core source of copper, zinc and sometimes gold mineralization for over 150 years and remain the mainstay of some major mining camps worldwide.

However, the three historically identified VMS camps in Mexico are seeing renewed exploration interest following decades of relative disinterest by miners.

In Mexico, three VMS districts have been identified to date. “These have not been a major focus for exploration because the other associated elements, particularly zinc, have not got the profile copper has,” says geologist and VMS expert James Franklin.

Franklin, a 2019 Canadian Mining Hall of Fame inductee for his pioneering work in developing models and techniques to guide exploration for VMS deposits, particularly in Canada, is currently an advisor to Mexico-focused explorer Vortex Metals (TSXV: VMS).

VMS mineralized structures formed on or very near the ocean floor throughout geological history.

“In Canada, for example, there are the major districts in Timmins, with Kidd Creek, which development companies such as Noranda became famous for, Mattagami Lake, Sturgeon Lake [and] quite a large number in British Columbia,” Franklin said in an interview.

While these deposits have been significant producers of zinc and copper worldwide, more recently, a subset of VMS deposits have been found to contain substantial amounts of gold.

Franklin explains that VMS deposits occur in somewhat geologically similar districts in relation to each other, mainly owing to their formation when the ocean floor collides with continents in what is called a ‘back-arc volcanic system’ that forms at varying water depths. They also tend to form on extensional ridges on the ocean floor.

“And they’re currently forming today. I’ve had extreme good luck in my career to spend ten years or so doing deep submergence diving and discovered some of these and then had an opportunity to drill what turned out to be the largest deposit ever discovered on the seafloor. That’s interesting academically, but economically, no chance,” said Franklin.

The largest VMS deposit in Mexico is Teck Resources’ (TSX: TECK.B) San Nicholas, in the central state of Zacatecas. According to Franklin, San Nicholas, along with every other district that contains VMS structures, usually entails a deposit in a set of deposits. And the deposits in any particular camp tend to be log-normally distributed. “So, you get one maybe supergiant deposit, and a bunch of medium-sized to small ones,” said Franklin.

VIDEO: Click here to listen to Dr. James Franklin explain how VMS deposits are formed

New understanding

Vortex Metals is exploring the southern Oaxaca state for what now forms the basis of its Riqueza Marina and Zaachila (RQMZ) copper-gold projects.

Vortex’s late chief geologist David Jones, a renowned professional, is credited with spearheading the discovery of 4 million oz. of gold in what became the Los Filos gold deposit in Mexico, now owned by Equinox Gold (TSX: EQX; ASE: EQX).

Jones was a recognized skarn expert and created the geological model responsible for multiple discoveries in what is now known as the 20-million-ounce Guerrero gold belt in Mexico, earning him the moniker “mine finder.”

Jones believed that both of the RQMZ projects would be significant discoveries, and he worked over the past 10 years to get the properties to their  current stage. The RQMZ projects comprise four exploration concessions in two blocks, Riqueza Marina and Zaachila, within an underexplored VMS district in southern Oaxaca.

The RQMZ concessions cover a cumulative area totalling 153  sq. km. within a geological province covering about 375 sq. km. Geology, geochemistry, and geophysics have identified five high potential target areas.

According to Franklin, who was also a former head of the Geological Survey of Canada, copper-gold mineralization contained within the RQMZ projects area and Minaurum Gold‘s (TSXV:MGG) Santa Marta project to the east represent oxidized portions of VMS mineralization.

The Riqueza Marina project and the Santa Marta deposit to the east are hosted by the Upper Jurassic-Lower Cretaceous package of metasediments and metavolcanics representing a back-arc system. They can be traced for over 200 km, says Franklin, who also compares the geological setting to that of the world-class Noranda VMS camp in Quebec.

Vortex has recently appointed a new social outreach representative on the ground who is engaging with local communities, a critical step before the company’s first drilling campaign can begin.

Following a $4.5-million capital raising in 2021, the company is fully funded for a $1.5-million drill campaign targeted for the latter part of 2022 and early 2023.

Vortex Metals’ Toronto-quoted equity last traded at 14¢ per share and is down 30% over the past 12 months. It has a market capitalization of $8.4 million. TNM