Corvus discovered the CIZ zone, an oxidised intrusive dyke swarm below the Mother Lode, late last year, hitting 50.3m at 1.5 grams per tonne gold, followed by 41m at 1.6g/t in January.
Having sent in a diamond rig to drill through the dyke area, the company said core and assays were indicating "mineralised intensity" and width increased at depth.
Corvus said the new zone had nearly a dozen known dykes and a higher temperature alteration assemblage, which suggested increasing intrusive activity with depth, which might explain the wider and higher-grade intervals intercepted in the hole, including a deeper intercept of 9m at 10.9g/t.
Oxidised mineralisation had now been traced to a depth of 650m.
The highest-grade intercept of the hole, all at a 1g/t cutoff, was 14.84m at 8.88g/t, "associated with higher temperature clay alteration and showing typical characteristics of deeper, hotter and more intrusion-related gold systems".
The characteristics of this type of gold system were "encouraging for a much larger and higher-grade system at depth".
CEO Jeffrey Pontius said development work was progressing quickly on a low-capex, phase-one starter project at nearby North Bullfrog.
"These exciting Corvus Gold developments are highlighting the potential of the Bullfrog District and along with new land acquisitions and discoveries by our neighbouring production companies it is shining a bright light on this under explored area of Nevada. We expect the Bullfrog District and Corvus will become one of the major focuses of the Nevada and North American gold sector in 2020," said Pontius.
Shares in Corvus (TSX: KOR) closed 15.7% higher on Wednesday at C$2.58, after setting a new 12-month high at $2.72 earlier in the day. It has a market cap of $320 million (US$227 million).