The Major occurrence is located on a steep southwest-facing slope, near an un-named creek flowing southwest into the Nomash River, approximately 3.3 kilometres southeast of its junction with the Zeballos River.
Regionally, the area is underlain by limestone and calcareous sedimentary rocks of the Quatsino Formation and basaltic volcanic rocks of the Karmutsen Formation, both of the Upper Triassic Vancouver Group. To the southwest, these have been intruded by granodioritic rocks of the Jurassic Island Plutonic Suite and quartz dioritic rocks of the Eocene to Oligocene Mount Washington Plutonic Suite.
Locally, two veins have been identified near the contact between Karmutsen Formation greenstone and overlying Quatsino Formation limestone.
The lower (Main) vein has been traced for approximately 150 metres, over elevations of 488 to 533 metres, and was explored by opencuts and two adits, totalling 21 metres. It is contained within a 6- to 12-metre wide feldspar porphyry dike striking 350 degrees with a dip of 65 degrees east and is up to 1.5 metres wide. Locally, pyrite and chalcopyrite are present in the quartz vein. At the adit, the vein is 60 centimetres wide with 23- to 36-centimetre chloritic gouge borders. The feldspar porphyry dike is strongly fractured and contains numerous smaller quartz veins.
The upper (Fissure) vein, located east of the lower (Main) vein, has been identified in outcrop and by opencuts at elevations of 680 to 735 metres. The vein has been traced for 90 metres along its 025 degrees strike with a dip of 60 to 80 degrees southeast. The vein varies in width from a few centimetres to 30 centimetres and hosts chalcopyrite, bornite and pyrite in quartz and minor calcite with fragments of volcanic rocks.
In 1938, a sample from the lower vein assayed 4.4 grams per tonne gold over 0.3 metre (Property File - C.C. Starr [1938-11-29]: Report on the Zeballos Dome Property).
Production in 1939, of 1 tonne containing 93.0 grams of gold, was from selected material.
In 1940, a selected sample assayed 16.0 grams per tonne gold (GSC Paper 40-12, page 36).
In 1995, a float sample (599534) assayed 0.46 gram per tonne gold, 2.8 grams per tonne silver and 0.188 per cent copper, whereas another float sample (599537) assayed 0.326 per cent copper and 0.196 per cent cobalt (Assessment Report 24184).
Additional mineralization is reported in Geological Survey of Canada Paper 40-12 (page 36) along the limestone-greenstone contact, where a 1.5-metre wide garnet-epidote-magnetite-pyrite zone carries small amounts of chalcopyrite. Below the contact the mafic volcanics are sheared and altered to serpentine-chlorite schist along a narrow zone striking 342 degrees and dipping 60 degrees east. Along this shear zone, over a width of 24 metres, pyrite, quartz (stringers?) and chalcopyrite are sparingly present.
In 1938, Reno Gold Mines Ltd. operated on the Zeballos Belle claims. By this time a 13.5-metre long crosscut tunnel had been driven at an elevation of 500 metres and a 7.5-metre long drift tunnel had been driven at an elevation of 520 metres.
In 1989, Golden Quadrant Resources completed 12.8 line-kilometres of ground electromagnetic and magnetic surveys on the area as the Nomash Silver claim. In 1994 and 1995, Orvana Minerals Corp. completed a program of rock and silt sampling and geological mapping on the area as the Nomash property.
In 2009, Global Silver Producers Ltd. and A25 Gold Producers Corp. prospected the area. No workings or mineralization were identified during this time. In 2017, Pacific West Stone Inc. completed a program of prospecting, geological mapping and rock sampling on the area.