Breccia, Baby, Breccia: News from the Izee

Brecciated core from Bayhorse Silver’s Underground Drilling Program

Getting ready to take the ferry over to Vancouver for VRIC 2025. Should be interesting and it will give me a chance to have breakfast (?!) with my pal Graeme O’Neill, CEO of Bayhorse Silver (BHS.V). Unfortunately, Hercules Metals (BIG.V) will not have a booth but I will see if I can track down its CEO, Chris Paul.

Both companies recently put out press releases. BIG is, of course, further advanced in its exploration of the suture of the Izee and Olds Ferry terranes at Mt. Cuddy in Idaho. Its release details a hole drilled at the project which “nicked” a mineralized hydrothermal breccia. Here’s the picture:

(click here to enbiggen)

“Breccia” means rubble and geologically it means rubble embedded in a matrix of other material. A hydrothermal breccia is created by super hot fluids pushing up from volcanic activity. Those fluids are often mineralized and, as illustrated above, the mineralized fluids can disseminate from the breccia creating a layer of enrichment. From an mineral exploration perspective, breccias are good in themselves and often key indicators of larger bodies of mineralization.

The market shrugged off BIG’s release. Which was likely a mistake as the release, as well as indicating a mineralized breccia, also put the “enrichment blanket” within 70 meters of the surface. One of the challenges facing BIG was that earlier drilling had the enrichment blanket hundreds of, largely barren, meters underground. A deep, low grade, deposit is not at all what the market wants to hear about. 70 meters? In the copper mining business that barely counts as cover. The grade in the breccia and enrichment layer is good with 138 meters of 1.01% CuEq.

Up the Snake River on the Oregon side, Bayhorse Silver got its drill turning underground and put out an Update press release so O’Neill could talk about the drilling so far at VRIC and Roundup. Overall, BHS has drilled 206 meters (675 feet) and is sending the bottom 115 meters (381 feet) for assay. As expected the top 91 meters (298 feet) appear barren and the company geos did not think it worthwhile to assay them.

The Company's senior consulting geologists have suggested the zone is a highly silicified hydrothermal polymictic breccia. It contains some rounded, possibly "milled" clasts that probably resulted from high pressure fluids derived from a buried pluton streaming up through the breccia.

Rock types that make up the bulk of the breccia include rhyolite, andesite, quartzite, meta sedimentary rocks and granite.

Without assays it is impossible to say what the Bayhorse breccia contains but the presence of hydrothermal breccia is a very encouraging signal. The company will continue to drill this first hole to a targetted depth of 260 meters (850 feet) likely in a continuation of the breccia. Where BIG “nicked” the breccia, BHS is drilling straight in. [I note that if the breccia continues down to 260 meters it is quite possible that BHS will continue to drill in this first hole for another couple of hundred feet. This would be especially attractive if the assays on the 381 feet are positive.)

As with all press releases there is a bit of decoding required. In this release, BHS commits to a program of downhole geophysics:

The downhole geophysical survey should discriminate between rocks that conduct electrical current and those that don't. There are areas of strong silicification, epithermal-style vuggy quartz veining and hydrothermal brecciation in Hole BH24-01. This alteration could mark the hole's proximity to porphyry or related epithermal mineralization.

Downhole IP surveying tools can also measure the chargeability of a rock which is its ability to hold a charge. Rocks with common but disconnected zones of sulfides have the largest chargeability responses and massive sulphides and copper porphyry are ideal chargeability targets.

Downhole IP is not terrifically expensive, but it isn’t free and BHS’s commitment suggests that the geo team is pretty sure that there is something worth finding. (It will also help identify new targets for the Bayhorse silver mine.)

The other interesting clue is that BHS is assaying for 35 elements plus gold. This makes sense as there have been gold showings historically and the company itself has reported gold in sampling programs in the mine. But, realistically, the core being assayed is hundreds of meters away from the mine workings. This tells me that the geos who are looking at the core want to confirm a hunch that there may be microscopic gold embedded in the breccia. Vuggy quartz veining is often associated with gold mineralization.

Both the BIG and the BHS releases are more confirmation of BHS geologist, Dr. Clay Conway’s theory:

Mineral deposit settings and relations at Bayhorse/Pegasus have similarities to those in the Cuddy Mountains district and also the Mineral district about 10 km north of Bayhorse mine. At each, silver mineralization is associated with rhyolite which is found at or near the regional contact between the Triassic-Jurassic Huntington Formation and the unconformably overlying Jurassic Weatherby Formation. Thus, silver mineralization at all three is potentially coeval – generated in the same regional magmatic episode. The newly discovered porphyry copper mineralization at Hercules is in shallow intrusions beneath the silver deposits and may be of this same magma generation. Thus, it may be inferred that porphyry copper deposits could be present at Bayhorse/Pegasus and also at the Mineral district.

The assays on the core BHS has recovered in its first underground hole will provide more evidence, one way or the other, for Dr. Conway’s theory and the general argument from similarity. A bit of gold would not be unwelcome.

(Disclaimer: I hold a small position in Hercules Metals. I own shares in Bayhorse Silver and may purchase or sell at any time. This is not investment advice. Do your own due diligence. Call the CEO.)