The Tildelsey Creek (Bornite 2 or Vass’s Pit) occurrence is located at an elevation of approximately 1340 metres on the north side of steep gorge, east of Tildesley Creek and approximately 9 kilometres west-northwest of Mount Sidney Williams.
Regionally, the area is underlain by Upper Paleozoic ultramafic and sedimentary rocks. This suite of rocks is of probable ophiolitic affinity related to the oceanic Upper Paleozoic Cache Creek Group on which it lies.
The eastern part of the Bornite claim group, on the east side of Tildesley Creek, is underlain by fault-imbricated slivers of ultramafic rock, slate and siltstone, and greenstone. These rocks are inferred to represent either the North Arm succession or the Sitlika Assemblage imbricated with the ultramafic unit in the footwall of the Mount Sidney Williams ultramafic allochthon.
The ultramafics are highly anomalous in nickel, which occurs as heazlewoodite, bravoite, siegenite(?) and native nickel-iron alloy. In addition, certain phases of the ultramafic are highly anomalous in gold. The nickel sulphides occur as disseminations and on fractures throughout the ultramafic.
Locally, a felsic peridotite or dunite hosts semi-massive to massive bornite and lesser covellite associated with magnetite and malachite-azurite staining. The mineralized zone is associated with a lateral fault or shear zone. At least two small pods of chromite, each approximately 0.75 by 1.75 metres in surface area, occur within sheared and serpentinized dunite to the west of the previous zone. Lower grade disseminated chromite occurs in dunite surrounding the lenses, over an area of approximately 2.1 by 6.7 metres.
In 1995, diamond drilling yielded intercepts of 0.171 per cent nickel and 0.009 per cent cobalt over 71.43 metres (1.52 to 73.15 metres down hole) in hole B95-4 and 0.195 per cent nickel with 0.008 per cent cobalt over 58.83 metres in hole 95-4A (Assessment Report 24277). Also at this time, eight chip samples (142375, 142377, 142378, 142380, 142806, 142808, 142815 and 142825) of serpentinite and/or serpentinized dunite with magnetite ± talc from the area of drillhole B95-4 yielded from 0.115 to 0.862 gram per tonne gold and 0.120 to 0.231 per cent nickel over 1.0 metre with an average of 0.16 per cent nickel over 25 metres (Assessment Report 24277 and Property File 520945).
In 1997, a rock sample (142319) from the area of drillhole 95-4 yielded 0.401 gram per tonne gold and 0.191 per cent nickel (Assessment Report 25477).
In 1998, three rock samples (142684, 142685 and 142688) from the area assayed from 0.127 to 0.184 per cent nickel and 0.082 to 0.086 per cent chromium (Assessment Report 25668).
In 2002, a sample (158646) of felsic peridotite with massive bornite mineralization from Vass’s Pit assayed 8.141 per cent copper, 80.1 grams per tonne silver, 0.135 per cent nickel, 0.065 per cent cobalt and 0.670 gram per tonne gold (Assessment Report 27104).
In 2004, a rock sample (158763) of serpentinized dunite, located approximately 400 metres north of the main zone, assayed 0.285 gram per tonne gold and 0.198 per cent nickel (Assessment Report 27723).
In 2012, rock samples are reported to have yielded up to 0.317 per cent nickel (Assessment Report 33589).
Approximately 1 kilometres northeast of the main Tildelsey Creek zone, a 300 metre long zone of brecciated ultramafics with talc-carbonate alteration, parallel to an aplite dike(?), contains coarse-grained disseminated pyrrhotite with chalcopyrite intergrowths. In 1998, sampling of this zone yielded up to 0.204 per cent nickel and 0.011 per cent chromium (Assessment Report 25668).
Work History
In 1995, Hera Resources Inc. completed a program of rock and soil sampling and five diamond drill holes, totalling 893.6 metres, on the area as the Bornite 1-11 claims. Three of these drillholes were completed on the eastern part of the Bornite claim group in the area of the Tildesley Creek occurrence.
During 1997 through 2012, Ursula Mowat completed programs of prospecting, rock sampling and geological mapping on the area as the Bornite property.
