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File Created: 24-Jul-1985 by BC Geological Survey (BCGS)
Last Edit:  23-Jan-2022 by Del Ferguson (DF)

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NMI
Name LEORA, JEAN (L.1684), DONALD (L.1685), JACK (L.1686), LOST CANYON, SYLVANITE, VIVA I, VIVA II Mining Division Alberni
BCGS Map 092F013
Status Past Producer NTS Map 092F03W
Latitude 049º 08' 01'' UTM 10 (NAD 83)
Longitude 125º 24' 45'' Northing 5445111
Easting 324024
Commodities Gold, Silver, Zinc, Cadmium, Tungsten, Copper Deposit Types I06 : Cu+/-Ag quartz veins
Tectonic Belt Insular Terrane Wrangell
Capsule Geology

The Leora occurrence is on the east side of the Kennedy River, below Boulder Creek, approximately 23 kilometres north-northeast of Ucluelet, B.C.

The area is underlain by basaltic andesite of the Upper Triassic Vancouver Group, Karmutsen Formation which has been intruded by a dacite dike, believed to be Tertiary in age (Assessment Report 15956, Figure 4). The Karmutsen rocks have undergone regional greenschist facies metamorphism. The dacite dike contains fragments of Karmutsen rocks, and fine-grained disseminated pyrite, particularly near the dike margins. Volcanic breccia containing bleached andesite fragments occurs 400 metres southeast of the Number Two adit, and is also interpreted to be of Tertiary age.

Two structures cut the volcanic rocks, the Boulder Creek fault and the Leora fault. The Boulder Creek fault trends 135 degrees and dips vertically, and is accompanied by argillic alteration, bleaching and fracturing of the host rock. The Leora fault, with which the known mineralization is associated, strikes 090 to 130 degrees and dips 55 to 75 degrees north. This structure is accompanied by crackle breccia and gouge, with at least five narrow quartz-calcite veins and several weak crosscutting veins. The veins carry pyrite, chalcopyrite and sphalerite.

Four levels were developed on the mineralized structure two of which are accessible through adits, one through a shaft and a fourth through a shaft and winze, which is now believed to be flooded and caved.

1.) The Number One level explores the eastern part of the structure at an elevation of 54.8 metres. A poorly developed andesite crackle breccia is exposed which is flanked on the south by massive andesite and on the north by a narrow quartz carbonate gouge vein dipping 75 degrees to the north. At the east end of the drift the breccia appears to turn to the north and then again to the east. A second quartz carbonate vein occurs at the north margin of the breccia and a large splay within the breccia is filled with carbonate minerals. Several minor cross cutting veins are noted. In 1984, of the Number One level yielded values up to 11.0 grams per tonne gold over narrow widths (Assessment Report 15956).

2.) Most of the development has taken place on the Number Two level. It explores approximately 82 metres of at least five separate vein structures at an elevation of 35.2 metres. A crackle breccia zone is exposed along much of this zone with wall rock alteration consisting of minor bleaching and pyritization. In 1984, sampling of the Number Two level yielded values up to 132.50 grams per tonne gold and a 19 metre section averaged 5.14 grams per tonne gold (Assessment Report 15956, page 10). Sample #R4699 from the Number Two level dump assayed 10.29 grams per tonne silver, 6.38 grams per tonne gold, 0.016 per cent tungsten, greater than 2.0 per cent zinc, and 0.2 per cent cadmium (Assessment Report 15956).

3.) The Number Three level is un-accessible due to flooding and caving.

4.) The Number Four Level is accessed through the Leora shaft and exposes approximately 27 metres of the main vein structure at an elevation of 12 metres. A crackle breccia zone occurs at the hanging wall of the vein and decreases markedly in intensity. Alteration of the wall rock consists of minor bleaching and pyritization. In 1984, sampling of the vein yielded values up to 28.9 grams per tonne gold over erratic and narrow intervals (Assessment Report 15956).

Intermittent production between 1902 and 1915 produced 383 tonnes of ore containing 8771 grams of gold and 2831 grams of silver.

In 1975 and 1979, Viva Ventures completed programs of prospecting and rock sampling on and around the former workings. Select samples of mineralized vein material assayed up to 300.13 grams per tonne gold (Assessment Report 05711).

In 1985, Discovery Gold Explorations Limited completed 5 diamond drill holes, totalling 211.2 metres. Two holes drill to the west of the old working indicated the quartz vein was present but without sulphides or gold values. Drill holes 1 and 4, were completed beneath the former workings and returned intercepts of mineralized quartz vein yielding 23.9 grams per tonne gold over 0.24 metres and 4.5 grams per tonne gold over 0.43 metres, respectively (Assessment Report 15842).

In 1990 and 1991, G. Kinneard completed programs of geological mapping and ground electromagnetic and self-potential surveys on the area.

A rock and soil geochemical survey was accomplished northwest of the LEORA mine in 2012 to 2014 by Gonzaga Resources Ltd., outlining both rock and soil anomalies (see MINFILE 09E 392 GUPPY).

Bibliography
EMPR AR 1902-232; 1903-192; 1909-147,274; 1910-152,245; 1912-195; 1913-278; 1914-375; 1915-287; 1916-329; 1919-197; 1927-343; 1932-204; 1933-251; 1935-F46
EMPR ASS RPT 5711, 7665, 12557, *15842, *15956, 20058, 21389, 34847
EMPR BULL 1, p. 134
EMPR EXPL 1979-129; 1983-200; 1987-C142
EMPR GEM 1975-E96
EMPR OF 1991-17
GSC MAP 17-1968; 1386A
GSC MEM 204, p. 34
GSC OF 9; 61; 463
GSC P 66-1; 68-50, p.48; 72-44
GCNL #103, #108, 1985
Carson, D.J.T., (1968): Metallogenic Study of Vancouver Island with Emphasis on the Relationship of Plutonic Rocks and Mineral Deposits, Ph.D. Thesis, Carleton University
EMPR PFD 6696, 827038

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