The Orwill prospect is characterized by mineralized quartz veins containing significant gold and silver values. It is located 2.5 kilometres northwest of Klinaklini River, 20 kilometres northeast of Klinaklini Lake.
The occurrence lies in the Stikinia Terrane, within a large quartz diorite intrusion related to the Jurassic to Tertiary Coast Plutonic Complex (Geological Survey of Canada Open File 1163, Map 1713A). The quartz diorite is dated at 66 million years (Late Cretaceous) by the potassium-argon method on hornblende and biotite (Geological Survey of Canada Open File 1163). It has a coarse-grained, equigranular to gneissic texture. To the southeast of the intrusion, and weakly contact metamorphosed by it, are Cretaceous volcanics and minor sedimentary rocks of the Gambier overlap assemblage (Geological Survey of Canada Map 1713A). These rocks comprise andesitic and basaltic lapilli tuffs, breccia and minor shale, siltstone, greywacke and conglomerate. Relict bedding is preserved locally. Two major faults occur east of the area: the northwest-trending, steeply southwest-dipping Tchaikazan fault is truncated by a northeast-trending fault in the Klinaklini River valley.
More recently a small triangular wedge of volcaniclastics of Upper Triassic age has been defined between the intrusions and the Cretaceous rocks to the southeast and is important as it encompasses the Orwill prospect (see BC Ministry of Energy and Mines, MapPlace). This Upper Triassic triangular wedge is bound on the west and the southeast by intersecting thrust faults; on the north side the volcaniclastics are in contact with Late Cretaceous to Paleocene granodiorite of the Bendor Suite. This Upper Triassic wedge has been assigned to the Mosely Formation.
The Main showing of the Orwill prospect occurs in a roof pendant of volcanic or volcaniclastic rocks, about 750 metres inside the border of the quartz diorite intrusion. A dike-like phase of the intrusion, a porphyritic microdiorite, occurs near the contact with the volcanics. The volcanics are strongly hornfelsed and they and the microdiorite are marked by fracturing and veining, associated with disseminated arsenopyrite (up to 10 per cent), pyrite and pyrrhotite. The latter minerals may be oxidized, producing gossanous outcrops. Hydrothermal alteration present includes silicification and bleaching and the production of sericite, chlorite and biotite. All the above features increase with proximity to the Main showing, which measures about 16 by 8 metres. Most of the work done has been at the Main showing, although minor mineralization and soil anomalies are present elsewhere on the property.
Mineralization at the Main showing is concentrated in strongly fractured and altered microdiorite, and to a lesser degree in the hornfelsed volcanics. It occurs as disseminated sulphides, but more importantly in discontinuous lenses, veins and fracture-fillings of quartz, generally between 5 and 15 centimetres thick, and locally in massive sulphide lenses up to 2 by 0.3 metres. At least 5 significant veins have been discovered. The paragenesis is arsenopyrite, boulangerite, chalcopyrite, pyrite, native bismuth, gold-bismuth and gold; minor galena, sphalerite, stibnite and pyrrhotite are associated (Assessment Report 19245). As well as native gold, gold is present as fine grains in arsenopyrite. Argentite is also reported (Assessment Reports 4572, 11114).
Recorded gold and silver values are high but sporadic. The best assay results reported for chip and rock samples from the Main showing are in the ranges of 15 to 52 grams per tonne gold, and 6.8 to 51 grams per tonne silver (Assessment Reports 4572, 11114, 11994, 17528). Gold and silver each assayed 7.5 grams per tonne over a 30- centimetre core sample from 29 metres vertically below the surface (Assessment Report 4572). Other notable analyses are up to 1.61 per cent copper, 0.61 per cent zinc, 0.82 per cent lead, 0.084 per cent antimony and 0.003 per cent bismuth (Assessment Reports 4572, 11994, 19245). One sample contained anomalous scandium (Assessment Report 17528).
Fracture and vein orientations vary from northeast to northwest; dips vary widely from 20 degrees to vertical. They are probably related to the two major faults. Overall, the deposit appears to be structurally controlled along a northerly trend.
WORK HISTORY
In 1972 and 1973, McLeod Copper Ltd and Cadillac Explorations Limited conducted geological mapping, drilling of 201.5 metres in three holes at the Main Showing on the Orwill claims (Assessment Report 4572; no logs for the drill holes were filed with this report; the best value – 7.5 grams per tonne gold (0.220 oz/ton) - was obtained from a 30 centimetre core interval in hole # 2).
In 1975, Asarco Incorporated conducted geological mapping and a geochemical survey, collecting 327 soil and silt samples; this work was not filed for assessment.
I n 1979, the ground was restaked by Mr. 0. Stowell, as the Lisa group of four 2-post claims. The claims were transferred over to Rhyolite Resources Inc. by Bill of Sale. In 1982 and 1983, Rhyolite Resources completed reconnaissance geochemistry, detailed soil geochemistry and geological mapping on three grids (Assessment Reports 11114 and 11994).
In 1987, geologist M.L. Serack and claim owner O. Stowell prospected the Pine and Woods Claims and returned to the claims in early 1988 for further prospecting and sampling (Assessment Report 17528). Fourteen rocks were collected and analyzed and 2 petrographic studies were completed. Bond Gold optioned the property from Orville Stowell and Susan Fadenrecht. In 1988, Bond Gold Canada Inc. contracted MPH Consulting Ltd. to carry out 52.6 kilometres of line cutting and 48.5-line kilometers of magnetic and VLF-EM surveys over the expanded Pine and Woods property (Assessment Report 18270).
In 1989, Bond Gold Canada Inc conducted a geological/geochemical exploration program on its Pine Woods Property (Assessment Report 19245). The work concentrated on an area between lines 5N and 5S, 500E to lOOOW of the exploration grid established during the summer of 1988. The geophysical surveys (VLF-EM) carried out during the 1988 field season had defined several targets in this area (Knights 1988). The 1989 program consisted of 1:2500 geological mapping with more detailed mapping in selected areas (Main Showing, South Zone, SW Area), rock sampling (99 samples), soil sampling (255 samples), humus sampling (60 samples), and heavy mineral stream sediment sampling (17 samples).
