The Biddy occurrence is located near the headwaters of Big Creek, approximately 7 kilometres north-northeast of Nina Lake and approximately 3 kilometres south-southwest of Razorback Mountain. It lies within 1 kilometre to the west of the Otter Lakes, near an old exploration gravel road that connects to the Germansen Landing road south of Nina Lake.
Regionally, the general area is divided by a major, layer parallel, thrust fault that separates para-autochthonous North American rocks of the Cassiar Terrane from rocks belonging to the Intermontane Superterrane represented by the Slide Mountain and Quesnel terranes (Ferri and Melville, Bulletin 91). This fault boundary roughly corresponds to the Omineca-Intermontane belts boundary. This regional stratigraphy forms part of a southwest-dipping homoclinal sequence that is cut by a series of northwest-striking normal faults to the north of the Biddy occurrence and northeast-striking normal faults to the south. With the exception of the easternmost portions of the pericratonic strata, all other rocks have been weakly metamorphosed up to chlorite grade (Ferri and Melville, Bulletin 91, and Exploration in British Columbia 1989, pages 193-196).
The Cassiar Terrane is represented by a Proterozoic to Mississippian carbonate and siliciclastic miogeoclinal wedge. These sequences of miogeoclinal rocks include the Proterozoic Ingenika Group, the Lower Cambrian Atan Group, the Cambrian (?) to Ordovician Razorback Mountain Group, the Silurian to Lower Devonian Echo Lake Group, the Middle Devonian Otter Lakes Group, the Upper (?) Devonian to Mississippian Big Creek Group and the Mississippian to Permian Cooper Ridge Group (Ferri and Melville, Bulletin 91).
The Slide Mountain Terrane is represented by Upper Paleozoic oceanic rocks of the Nina Creek Group. The Pennsylvanian to Permian Nina Creek Group consists of a lower argillite-dominated sedimentary package and an upper pillowed to massive basalt-dominated sequence. Rocks belonging to the Quesnel Terrane lie to the west of the Nina Creek Group, across the Manson fault zone, and are represented by the Middle Triassic to Lower Jurassic Takla Group.
The Biddy occurrence is hosted within the Middle Devonian Otter Lakes Group and the Silurian to Lower Devonian Echo Lake Group. The Otter Lakes Group is characterized by approximately 150 to 200 metres of grey to black limestones and dolostones that are direct correlatives of the carbonates of the McDame Group in the Cassiar area (Ferri and Melville, Bulletin 91). The Echo Lake Group is a thick succession of approximately 100 metres of limestone, dolomite, sandy dolomite and minor quartzite. It is divided into two units with the lower unit consisting primarily of carbonate and the upper unit, sandy dolomites and quartzites. Overlying these two groups is the Upper (?) Devonian to Lower Mississippian Big Creek Group that is approximately a 500 metre thick succession of blue-grey to dark grey shales, argillites and minor sandstones.
Mineralization is stratabound within a stratigraphic interval from the Otter Lakes-Big Creek contact downwards to the uppermost sandy dolomites of the Echo Lake Group. The sulphides occur as semimassive irregular-shaped pods in solution breccias (dolomitic breccias), as massive sulphides in localized shear zones and as disseminated blebs in arenaceous dolomites. Where brecciated, the mineralization is found towards the top of the Otter Lakes Group, near the Big Creek shale contact. The sulphides within the breccias may replace clasts, matrix or a combination of both suggesting multiphase fluid influx and deposition (Exploration in British Columbia 1989, pages 193-196). Mineralization consists of sphalerite and galena with associated barite and minor pyrite. Lead-lead dates from the galena have a Cambrian shale curve model age (Ferri and Melville, Bulletin 91).
The Biddy Main zone is characterized by large collapsed breccia zones with minor sphalerite (rare galena) that are enhanced by shear-related massive sulphide infilling. Patches, layers and bands of massive argentiferous reddish sphalerite are of primary interest due to high critical metal (Germaium-Galium-Indium) content (Assessment Report 38519). The sphalerite is on average 0.05 per cent germanium (Assessment Report 16946).
Work History
The Biddy group was first described in 1956 by Clive W. Ball at Canadian Exploration Ltd. as an economically favorable disseminated lead-zinc mineralization near an important structural feature between argillite and limestone, which was thought to carry the dolomite and lead-zinc horizons (Property File 810517).
This description heightened economic interest in the area, and in 1988 a joint venture between Equinox Resources Ltd. and Daren Resources Ltd. refined the extent of the adjoining Jemima (MINFILE 093N 011) occurrence and the Biddy occurrence was established. Both occurrences are hosted in a northwest-trending fault that curves to a northeast trend in the Otter Lakes Group (Assessment Report 16946).
Between 1986 and 1988 the joint venture explored the Biddy occurrence, and trenching located a number of mineralized showings, all structurally controlled in a narrow zone. The 1986 field program at Nina Lake for trace element value evaluation from rock samples yielded two samples from the Biddy area, one (Sample 11) with 1.01 per cent zinc, and the other (Sample 19) with 4.57 per cent zinc (Assessment Report 16946). Within trench 13, sphalerite was noted to occur as orange grains and patches disseminated in either original porous zones, such as sandstones and arenaceous dolomite, with 1.5 per cent zinc across 10 metres (representing approximately 2.5 metres of true section), or as tectonically prepared porous-permeable zones such as the ‘impregnated dolomite’ breccia in the ‘pit’ area, with 1.2 per cent zinc over 10 metres (Assessment Report 16946). An east-west fault cutting across the Centre pit showed 1.95 per cent zinc, 1.25 per cent lead across 1 metre and, at the northern end of trench 45, resulted in zinc at 3.5 per cent (Assessment Report 16946).
Also at this time, a grab sample from this occurrence analyzed 4.11 per cent zinc, 28 grams per tonne silver and 0.120 per cent germanium (Exploration in British Columbia 1989, page 195).
In 1990, Equinox Resources Ltd and Daren Resources Ltd. conducted diamond drilling on the occurrence. One of the best drillhole intersections (DDH90-11) from this work analyzed 1.3 per cent zinc and 1 per cent lead over a 2-metre interval (Assessment Report 20492).
In 2006, a detailed compilation of historical geochemical soil sampling, as well as an air photo lineament study was conducted by B.K. (Barney) Bowen, P.Eng, of Surrey, British Columbia, and covered the Biddy area, but no work was performed on the occurrence (Assessment Report 28634).
In 2019, extensive geochemical work and rock chip sampling was completed on the Biddy main zone. A total of 15 rock samples (19BID-1 to 11, 16-19) were taken from the Biddy main zone outcrop and float. Samples 19BID-8 (outcrop), 19BID-9 (angular float) and 19BID -10 (outcrop) resulted in zinc values of 19.1, 24.4 and greater than 30.0 per cent, respectively, with samples 19BID-12 to -13 (outcrop) and 19Bid-14 to -17(angular float) showing zinc values of 14.85 per cent, 21.7 per cent, 7.49 per cent, 7.77 per cent, 6.31 per cent and 1.42 per cent, respectively. Sample 19BID-12 also yielded 5.15 per cent lead (Assessment Report 38519).
