The Forks 4 occurrence is located on an un-named, north-flowing tributary of the Mackay River, approximately 3 kilometres southeast of the river’s junction with the Horsefly River. The un-named creek is referred to as the ‘No. 1 Creek’ in associated reports.
Regionally, the area is underlain by mudstone, siltstone, shale and fine clastic sedimentary rocks of the Middle to Upper Triassic Nicola Group and Triassic Slocan Group. To the east, serpentinite ultramafic rocks of the Upper Paleozoic Crooked amphibolite and metasedimentary rocks of the Neoproterozoic to Paleozoic Snowshoe Group are exposed.
Locally, the area is underlain mainly by basal black phyllite interbedded with pyritic sericite phyllite of the Slocan Group. These rocks form the upright northeast limb of the major northwest-trending Eureka syncline. Locally, the rocks form asymmetric drag folds that contain metamorphically derived quartz (‘sweats’) in the hinges. For more detailed regional and local geology descriptions see the Frasergold (MINFILE 093A 150) occurrence.
Mineralization is associated with the ‘knotted’ or porphyroblastic black phyllite unit, which occurs in a 200- to 300-metre wide zone within the phyllite sequence. Gold mineralization typically occurs near the base of the knotted phyllite. The quartz sweats host gold mineralization (rarely visible) and quartz-carbonate material. The mineralized zone is characterized by a high percentage of boudinaged quartz veins with minor pyrite, limonite, and iron carbonate (siderite) hosted in a graphitic and locally sheared phyllite within a more massive-type porphyroblastic phyllite.
In 1987, a rock sample (B9867) of sericite phyllite assayed 0.10 gram per tonne gold and 4.45 grams per tonne silver (Assessment Report 16961).
In 1988, samples assayed up to 0.07 gram per tonne gold, 5.1 grams per tonne silver and 0.06 per cent zinc (Assessment Report 18471).
In 1989, a surface sample (27814) assayed 3.39 grams per tonne gold, whereas drilling yielded intercepts assaying up to 0.51 gram per tonne gold over 1.2 metres and 0.34 gram per tonne gold over 1.5 metres in hole 89-8 (Assessment Report 19497).
The area has been historically explored in conjunction with the nearby Frasergold (MINFILE 093A 150) and TEP 1 (MINFILE 093A 092) occurrences. During the 1980s, Eureka Resources Inc. completed programs of geochemical sampling, ground geophysical surveys, geological mapping and minor trenching on the area immediately southeast as the Mac 10 claim. This work identified areas of anomalous gold-in-soil with values up to 1100 parts per billion gold (Assessment Report 16917), and a sample (81-Bf-145A) of rusty quartz float or subcrop hosting localized pyrite and galena assayed 5.70 grams per tonne gold, 136.1 grams per tonne silver and 0.414 per cent lead (Assessment Report 9751).
In 1981, Dennison Mines Ltd. soil sampled the area of the Forks 1-4 claims. In 1983, Ripple Resources Ltd. conducted a program of soil sampling and a lone drillhole on the area as the Bee 1-2 claims. In 1984, Valhalla Minerals Inc. soil sampling the area immediately southeast as the LL-1 claim.
In 1987, Armada Gold and Minerals Ltd. conducted a program of rock, soil and silt sampling and regional mapping of the Forks, AR and TEP claim groups. The following year, a program of extensive trenching, further detailed geological mapping and five diamond drill holes, totalling 918 metres, was completed on the claims. In 1989, Arrowfield Resources Ltd. and Armada Gold and Minerals Ltd. completed a program of rock, silt and soil sampling, geological mapping and four diamond drill holes, totalling 616 metres, on the Forks and TEP claims.
During 2010 through 2012, Bullion Gold Corp. completed programs of soil sampling, a 45.5 line-kilometre induced polarization survey and 1874.0 line-kilometres of airborne geophysical surveying on the area as part of the Cariboo Goldfields and Horsefly properties. In 2015, the area immediately southeast was prospected, mapped and rock sampled as the Hawk claim.
