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File Created: 24-Jul-1985 by BC Geological Survey (BCGS)
Last Edit:  19-Jan-1991 by Dorthe E. Jakobsen (DEJ)

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NMI 092C15 Cu2
Name ROB, BORNITE, O.G.M., NADIRA, WALLY, HAPPY CAMPER Mining Division Alberni
BCGS Map 092C097
Status Past Producer NTS Map 092C15E
Latitude 048º 55' 25'' UTM 10 (NAD 83)
Longitude 124º 35' 55'' Northing 5420196
Easting 382897
Commodities Copper, Silver, Lead Deposit Types
Tectonic Belt Insular Terrane Wrangell
Capsule Geology

The Rob occurrence is located 9.7 kilometres due west of Cowichan Lake on Horse Creek.

The property was initially staked as the Southern Cross in the 1930's to cover a skarn zone mineralized with copper and magnetite. The property was intermittently explored between 1941 and 1960. In 1960, a test run of 4665 tonnes was taken from open pits, producing 61,929 kilograms of copper. Exploration commenced again in 1969 continuing until 1972. No further work was undertaken until 1986 when the skarn mineralization was tested for gold content.

The area is underlain by sedimentary and volcanic rocks of the Upper Triassic Vancouver Group and the Lower Jurassic Bonanza Group. The Vancouver Group comprises limestone, calcareous siltstone, shale, cherty limestone and chert of the Quatsino Formation and pillow basalt, tuff, breccia and minor flows of the Karmut- sen Formation. The Bonanza Group consists of basaltic to rhyolitic tuff, breccias and flows with minor greywacke and argillite. These have been intruded by Early to Middle Jurassic Island Plutonic Suite granitic rocks and feldspar porphyry dykes of unknown affinity. The area is structurally complex, containing several sets of faults with evidence of drag folding.

Skarn mineralization is hosted in Quatsino Formation limestone and porphyritic andesite of the Bonanza Group near contacts with diorite intrusions and feldspar porphyry dykes.

Three types of skarn occur on the property:

1) Ilvaite-garnet-epidote-magnetite in calcium-rich rocks

2) Epidote-actinolite-garnet in less calcium-rich rocks (andesite

3) Laminated pyrrhotite-magnetite-chalcopyrite All three types contain chalcopyrite as erratic disseminations and as small masses along fractures and veinlets. Hematite, bornite and lesser pyrite and pyrrhotite are occasionally present. Malachite and azurite occur on fractures. Chalcopyrite and pyrite also occur in volcanic rocks, usually associated with epidote and quartz-filled amygdules. Chalcopyrite and galena were observed in limestone at one locality, and chalcopyrite has been noted in sheared diorite.

The main skarn zone, conformable with regional strike (strikes north-northwest, dips steeply south) is lenticular in shape and covers an area 610 by 152 metres. Skarn mineralization is exposed at widely scattered locations in creek gullies and along roads on the property. The best exposure is at the small pits developed in 1960 by Nadira Mines Ltd. The weighted average of 90 chip samples taken over a total of 235 metres was 1.73 per cent copper (ranging from 0.1 to 5.6 per cent) and 6.86 grams per tonne silver (Assessment Report 2115). A sampling program undertaken to assess the gold content of the skarns resulted in low values.

EMPR AR 1931-165; 1932-202; 1953-170; 1956-123; 1957-71; 1959-138; 1960-112
EMPR ASS RPT 291, *2115, 3098, 3375, *3723, *4105, *15015, 20031
EMPR FIELDWORK 1977, p. 23; 1989, pp. 503-510
EMPR GEM 1969-221; 1971-227
EMPR OF 1988-24; RGS 24, 1990
EMPR PF (In 092C General File - Aeromagnetic Contour Map, Nitinat Lake Area, Noranda Mines Ltd., date unknown; Nadira Mines Ltd. Self-Potential Survey Map, 1955; Nadira Mines Ltd., Prospectus 1956; Nadira Mines Ltd. Surface Survey maps & notes, 1960; *Dawson, J.M. (1971): Report on the Nadira Copper Property; Anselmo, G.L. (1972): Geochemical Report on Rob Claims; Homenuke, A.M. (1973): Nadira Copper Property - Rob Claims; Letter to Minister of Mines from Amax Explorations, Feb. 1975)
GSC OF 463; 821; 1272
GSC P 72-44; 76-1A; 79-30
Carson, D.J.T. (1968): Metallogenic study of Vancouver Island with emphasis on the relationships of mineral deposits to plutonic rocks, Ph.D. Thesis, Carleton University