The Billy Goat Bowl (Stu) occurrence is located approximately 5.7 kilometres south of the confluence of Snippaker Creek and Iskut River in northwest British Columbia, approximately 96 kilometres northwest of Stewart.
The oldest rocks in the area consist of Paleozoic crinoidal limestone which overlies metamorphosed sedimentary and volcanic members. Unconformably overlying the Paleozoic limestone unit are Upper Triassic Hazelton Group island are volcanics and sediments. Monotis fossils have been recognized on the north slope of Snippaker Peak giving an age of Upper Triassic. Some of the stratified rocks may be correlated with upper members of the Stuhini Group.
On the property, limestone is the oldest unit which is successively overlain by an argillite/siltstone/greywacke sequence which in turn is overlain by an andesite agglomerate unit. Feldspar porphyry and andesite dikes cut both the argillite/siltstone/greywacke and agglomerate.
In the central part of the Stu 2 claim, grey, massive, sometimes recrystallized limestone, forms an east trending wedge which is possibly in fault contact with the argillite/siltstone/greywacke sequence. This sedimentary sequence is bedded, fine-grained, black and is often silicified and strongly fractured. The sequence hosts known mineralization in areas of feldspar-porphyry and andesite diking.
In the Billy Goat Bowl Zone, mineralization is found covering an area of at least 500 by 700 metres, just southeast of the toe of Zappa Glacier. The gold-bearing mineralization occurs in iron-carbonate (calcite) veins which often host pyrite with minor galena and sphalerite. Sulphide veins vary from 2 to 4 centimetres and swell up to over 1.0 metre in width. The veins have been traced up to 50 metres along strike length and the general trend of the mineralized veins is about 090 degrees dipping 65 degrees south.
In 1987, a 0.35 metre wide sample taken from an iron-carbonate vein with massive pyrite assayed 17.21 grams per tonne gold. Seven other areas hosting similar mineralized iron-carbonate and quartz veins with pyrite plus or minus galena, plus or minus sphalerite, plus or minus chalcopyrite, were sampled. A 0.5 metre wide sample from Area 2 assayed 8.06 grams per tonne gold, 77.83 grams per tonne silver, 0.195 per cent copper, 0.10 per cent lead, 0.556 per cent zinc and 0.519 per cent arsenic. A 0.8 metre sample from Area 7 assayed 4.49 grams per tonne gold, 72.0 grams per tonne silver, 0.225 per cent copper, 7.08 per cent lead and 3.28 per cent zinc (Assessment Report 16930).
At least one prominent feldspar porphyry dike trending 040 degrees with a vertical dip, averaging 35 to 50 metres in width, appears to be responsible for mineralization in the Billy Goat Bowl Zone. Iron-carbonate/sulphide and mineralized quartz veins have only been seen adjacent to this dike. Also, related to the mineralization are several narrower andesite dikes which range up to 1.0 to 1.5 metres width.
In addition to the iron-carbonate/pyrite veins, several quartz veins were found to host sphalerite plus chalcopyrite plus galena. These veins host anomalous zinc values with very low gold values.
Several 1989 samples from various vein structures yielded anomalous values of copper, lead, and/or zinc but only one sample returned significant silver and gold values. This grab sample (83320) was collected from a 5 centimetre wide quartz-calcite vein near the Zappa Peak, located about 1.3 kilometres east of the Billy Goat Bowl zone. It assayed greater than 2 per cent copper, 0.93 per cent lead, 0.11 per cent zinc, 35.7 grams per tonne silver and 30.03 grams per tonne gold (Assessment Report 19638).
Kestrel Resources Ltd staked the Stu 1 and 2 mineral claims (36 units) in the fall of 1986. The ground was acquired t cover favourable geology immediately north of Inel Resources Ltd.'s polymetallic Inel deposit. In 1987, Kestrel spent a total of 99 man-days prospecting, mapping, rock chip and soil sampling and trenching. A total of 256 rock chip and 47 soil samples were collected. In 1987, four main areas of mineralization were identified: Billy Goat Bowl zone, the toe of Zappa Glacier, central Stu 2 claim area and the Magnetite zone.
The 1989 exploration program was undertaken to evaluate the remaining accessible but unexplored portions of the property and the four known zones of mineralization, namely the Billy Goat Bowl, tongue of the Zappa Glacier, central STU 2 and Magnetite zones.
The 1989 exploration program by Kestrel on the Stu 1 and 2 included prospecting and rock sampling (66 samples); detailed geological surveying of the Billy Goat Bowl and Ridge Zones; geophysical surveying - UTEM electromagnetics (10.8 kilometres.), magnetics (10.4 kilometres.) and VLF electromagnetics (200 metres); trenching (6 trenches for 40 metres); channel and chip sampling (25 samples). During the geological survey of the Ridge Zone, the Bear copper-bearing skarn zone was discovered, and it was subsequently hand trenched, geologically mapped and chip, panel, or channel sampled.
Rock sampling of the Billy Goat Bowl, Central Stu 2 (MINFILE 104B 311), and Magnetite (MINFILE 104B 313) area in 2014 by Colorado Resources Ltd. reported negligible gold values, however the approximately 60 samples taken average around 0.5 per cent copper (Assessment Report 35184).
In 2017, Colorado Resources field crews collected 13 rock samples from the area with 10 out of the 13 rock samples returned greater than 1000 parts per million copper and 8 out of 13 rock samples returned greater than 20 grams per tonne Ag, including 1,930 grams per tonne Ag which was also associated with elevated results for copper. Most of the elevated copper values are associated with narrow quartz-sulphide veins (Assessment Report 37604).