The Britannia M occurrence lies in the Zeballos gold camp and is located on the west side of a ridge separating Spud and Goldvalley Creek.
Regionally, the area is underlain by Upper Triassic to Lower Jurassic Bonanza Group basaltic to rhyolitic volcanic rocks. Conformably underlying the Bonanza volcanic rocks are limestones and limy clastics of the Triassic to Lower Jurassic Parson Bay Formation (Bonanza and Vancouver groups) and Upper Triassic Quatsino Formation (Vancouver Group), and tholeiitic basalts of the Upper Triassic Karmutsen Formation (Vancouver Group). Dioritic to granodioritic plutons of the Zeballos intrusion phase of the Jurassic Island Plutonic Suite have intruded all older rocks. The Zeballos stock, a quartz diorite phase of the Eocene to Oligocene Mount Washington Plutonic Suite, is spatially related to gold-quartz veining in the area. Bedded rocks are predominantly northwest striking, southwest dipping, and anticlinally folded about a northwest axis.
Locally, several quartz veins (Free Gold [Upper and Lower], Goat, Long, Cliff, Fir, Well, Lattice and other un-named veins) have been identified at on the M2 (L.1066), M5 (L.1070) and M6 Fraction (L.1069) Crown grants in Eocene quartz diorite or along the contact with Lower Jurassic Bonanza andesite (Figure 25, Bulletin 27). All eight of the veins strike east with a vertical dip, are composed of ribbons of quartz averaging 2.5 centimetres in width and are mineralized with fine-grained pyrite with minor calcite and arsenopyrite.
The Free Gold vein, located on the M6 Fraction (L.1069) Crown grant, is hosted by quartz diorite and has been explored by an adit (No. 4) over 36.0 metres along strike. The vuggy quartz vein varies from 7 to 17 centimetres in width and is reported to be sulphide poor. The vein strikes north 65 degrees east and splits into two stringers approximately 1.2 metres apart at a point approximately 29.4 metres from the adit portal. In 1937, samples from the upper and lower Free Gold vein were reported to have yielded 20.9 and 51.6 grams per tonne gold over 12 and 6 centimetres, respectively (Assessment Report 18577). In 1983, a sample (BM-001-83) assayed 47.32 grams per tonne gold, 9.7 grams per tonne silver and 0.79 per cent arsenic (Assessment Report 12077).
The Cliff vein is 7 centimetres wide and contains pyrite and graphite with possible two stages of veining in an altered quartz diorite host. In 1983, a sample (BM-002-83) assayed 3.5 grams per tonne gold, 1.8 grams per tonne silver and 0.792 per cent arsenic (Assessment Report 12077).
The Long vein, located on the M6 Fraction (L.1069) Crown grant a short distance north of the Free Gold vein, is 10 centimetres wide and was explored with a 24.6-metre adit. The vein strikes north 70 degrees east. In 1937, samples were reported to have yielded 6.5 grams per tonne gold (Assessment Report 18577).
The Goat vein, located south of the Free Gold vein on the M5 (L.1070) Crown grant, is reported to be 22.5 centimetres wide and was explored by an adit (No. 3) over a strike length of 30.0 metres. The vein strikes north 70 degrees east. In 1937, samples were reported to have yielded 10.6 grams per tonne gold (Assessment Report 18577).
The Well and Fir veins are located northwest of the Free Gold vein on the M2 (L.1066) Crown grant. No further information is reported
Work history.
During the 1930s, four of the veins (Free Gold, Long, Goat and Cliff) were explored with adits by Britannia Mining and Smelting Co. Ltd.
In 1983, Impact Resources Inc. completed a program of geological mapping and rock sampling on the Central Zeballos property.
During 2011 through 2013, North Bay Resources Inc. completed programs of prospecting and silt sampling the area as the Zeballos Gold property.
In 2018 and 2019, 640895 BC Ltd. completed programs of rock, silt and soil sampling on the area as the Zeballos property. A sample (A00343967) from a nearby float boulder of volcanics hosting sulphides assayed 6.03 grams per tonne gold (Assessment Report 38826).
