The playbook — copper · August 27, 2026
Massive sulphide hits at Mary March, and the market noticed
Canstar's first Mary March drilling since 2019 cut 15.6 m of massive sulphide at 2.3% CuEq — its widest ever, ~100 m along strike from the 1999 discovery hole.
Canstar Resources drilled a hole into an old Newfoundland mining district and pulled out rock loaded with metal. Hole MM-26-42 cut 15.6 metres of massive sulphide — rock logged as more than half sulphide minerals — grading 2.3% copper-equivalent (a blended number that rolls copper, zinc, lead, gold and silver into one figure). Inside that was a richer 9.75-metre core running 3.3% copper-equivalent, and a best five metres carrying 1.71% copper, 3.02% zinc and 32.6 grams of silver per tonne. This is the widest intercept in Mary March’s history, and it’s the first drilling here since 2019 — a seven-year gap now funded by earn-in partner VMSC, which has put C$4.0 million into the project.
Why it matters: this is a genuine polymetallic massive-sulphide hit, not thin disseminated grade. The hole sits roughly 100 metres along strike from the rich 1999 discovery hole, so a continuous VMS lens — a metal-rich body formed on an ancient seafloor — is plausible. Run the gram-meter math (grade times thickness, the quick yardstick for how much metal a hole carries) and the 15.6 m intercept scores about 36 copper-equivalent percent-metres — strong for a junior. The exploration muscle comes from VMSC’s Dr. Harold Gibson, a 40-year VMS authority. And the market paid attention: ROX.V rose 62.5% over three months while its copper-equity peer index gained 12.2% and copper itself gained 6.1% — a clean step-up on company-specific news, not sector drift. Eric Sprott sits on the share register.
What to watch: the honesty section. Only one hole has assayed massive sulphide. The second massive-sulphide intercept, in MM-26-44, is a visual log with no assays yet, and step-out MM-26-43 and hole MM-26-41 are also pending — expected through September. The company states plainly that true thickness is less than the 15.6-metre core length, and that the full width of the fault-bounded lens hasn’t been intersected, so the headline width overstates the real zone. The cut-off grade for the reported intervals was not disclosed in the release. A borehole electromagnetic survey is expected mid-September, and a fall Phase 2 campaign is targeted for October, subject to rig availability. At $0.065, this is micro-cap territory with elevated liquidity risk. One assayed hole is a promising system, not a deposit.