The Rea Gold deposit is situated on an unnamed tributary of Johnson Creek, southeast of Johnson Lake and approximately 21 kilometres east-southeast of the community of Barriere.

The deposit has been explored in conjunction with the past-producing Samatosum mine (MINFILE 082M 244), situated 800 metres to the southeast.

The area is underlain by four thrust-bounded sub-assemblages of the Early Cambrian to Late Mississippian Eagle Bay Formation: the Rea, Plateau, Homestake and Acacia assemblages. The Rea assemblage, which underlies the immediate area of the Twin occurrence, consists of a structurally inverted sequence of mafic pyroclastics and flows containing Tshinakin limestone. The mafic series is stratigraphically overlain and structurally underlain by a thick sequence of clastic sediments. The Rea zone, a 10 to 150-metre-thick section of stratigraphy at the mafic volcanic-sediment contact, hosts the Rea Gold, K-7 (MINFILE 082M 277) and Twin (MINFILE 082M 276) occurrences. The Plateau assemblage lies to the southwest and consists of mafic, intermediate and felsic volcanics with lesser interbedded argillite. Structurally underlying the Plateau assemblage is the Homestake assemblage, which consists of five distinct units consisting of calcareous sediments, mafic volcanics, sericite schists, interlayered sericite schist, phyllite, chert and argillite and unaltered felsic volcanics. Further south, well-bedded and complexly folded quartzites, quartz wackes, siltstones and argillites comprise the Acacia assemblage.

The deposit is hosted by chloritic phyllites, quartz-sericite schists and chert derived from predominantly mafic with minor intermediate to felsic volcanic and volcaniclastic rocks (Unit EBF) of the Lower Cambrian to Late Mississippian Eagle Bay Formation (Ministry of Energy, Mines and Petroleum Resources, Map 56). The rocks are underlain by sericitic phyllites derived from felsic to intermediate volcanics (Unit EBA), which host the Homestake deposit (MINFILE 082M 025) situated 4 kilometres to the south. These units are overlain by metasedimentary rocks consisting of argillites, siltstones and grits, which are structurally overlain to the east by mafic metavolcanics (Unit EBG). The deposit lies on the inverted northern limb of a northwest-trending, northeast-dipping, tight, overturned syncline.

Two massive sulphide lenses, situated 250 metres apart and at approximately the same stratigraphic level, occur at the stratigraphic top of a silicified tuff and exhalative chert sequence that lies above a thicker sequence of mafic ash, crystal and lapilli tuffs. Both lenses are stratigraphically overlain by a thin sequence of mafic tuff that grades up into argillites, wackes and grits. The southern lens is "capped" by a layer of massive barite.

The massive sulphides are underlain by a footwall feeder and alteration zone, characterized by intense silicification, pervasive pyrite and sericite development. As the stratigraphic succession is inverted, the "footwall alteration zone" or "stockwork feeder zone" forms the structural hanging wall of the sulphide lenses.

Mineralization within the sulphide lenses includes pyrite, sphalerite, galena, arsenopyrite, chalcopyrite and tetrahedrite-tennantite. The sulphides range from fine grained and massive with a faint breccia texture, to medium grained and banded (Fieldwork 1984). Gold and silver is associated with the massive sulphides and barite.

The southern lens (L98 lens) has a surface strike length of 75 metres and a downdip extension of at least 80 metres. Up to 8-metre widths of massive sulphides have been intersected by drilling.

The northern lens (L100 lens), or Discovery lens, has a surface strike length of approximately 50 metres, a width of approximately 4 metres and a downdip projection of at least 120 metres. The lens strikes 140 degrees and dips 50 to 60 degrees northeastward. Measured geological reserves are estimated at 242 849 tonnes grading 6.51 grams per tonne gold, 73.37 grams per tonne silver, 2.14 per cent lead, 2.24 per cent zinc and 0.52 per cent copper (George Cross News Letter #8, 1987).

The southern or L98 lens contains measured geological reserves of 133 536 tonnes grading 61.71 grams per tonne silver, 5.41 grams per tonne gold, 0.69 per cent copper, 2.4 per cent lead and 2.4 per cent zinc (Northern Miner, November 30, 1987).

Indicated reserves for the northern and southern lenses are 376 000 tonnes grading 0.33 per cent copper, 2.2 per cent lead, 2.3 per cent zinc, 6.1 grams per tonne gold and 69.4 grams per tonne silver (George Cross News Letter #8, 1987; Northern Miner, November 30, 1987).

In 1988, underground drilling on the L98 lens yielded intercepts including 14.74 grams per tonne gold, 98.3 grams per tonne silver, 4.38 per cent lead, 6.07 per cent zinc and 1.15 per cent copper over 9.2 metres in hole UG88-4; 12.58 grams per tonne gold, 113.7 grams per tonne silver, 5.00 per cent lead, 6.35 per cent zinc and 1.09 per cent copper over 10.7 metres in hole UG88-12; 9.37 grams per tonne gold, 95.2 grams per tonne silver, 4.44 per cent lead, 6.79 per cent zinc and 1.11 per cent copper over 11.3 metres in hole UG88-13; 22.02 grams per tonne gold, 101.0 grams per tonne silver, 4.83 per cent lead, 7.08 per cent zinc and 1.26 per cent copper over 3.4 metres in hole UG88-14; 11.58 grams per tonne gold, 82.2 grams per tonne silver, 4.27 per cent lead, 6.15 per cent zinc and 0.92 per cent copper over 7.75 metres in hole UG88-17 and 5.59 grams per tonne gold, 102.7 grams per tonne silver, 3.65 per cent lead, 4.74 per cent zinc and 0.89 per cent copper over 14.9 metres in hole UG88-18 (Property File – Rea Gold Corp. [1988-09-01]: Geological and Drilling Report on the Underground Exploration of the L98 Orebody).

Also at this time, sampling of the No. 1 and 2 cross-cuts on the L98 lens yielded average grades of 19.8 and 6.7 grams per tonne gold, 133.8 and 98.8 grams per tonne silver, 3.65 and 3.01 per cent zinc, 4.58 and 4.21 per cent lead with 0.95 and 0.74 per cent copper over 6.48 and 4.44 metres, respectively (Property File – Reaugh, L.W. [1988-03-11]: News Release - Rea Gold Corp. - Complete sets of results from detailed sampling of both walls of the number one crosscut at the L98 lens).

Work History

Exploration in the area began in the late 1800s. To the southwest, exploration for copper, lead, zinc, gold, silver and barite began at the Homestake mine (MINFILE 082 025) in 1893. Limited production took place from 1926 to 1927, 1935 to 1936 and 1983 to 1984. To the east, the Twin Mountain zone has been explored intermittently since 1936. Exploration focused on massive copper, lead, zinc and barite sulphides.

A massive sulphide outcrop known as the Rea Gold occurrence was discovered by A. Hilton in the summer of 1983. The occurrence was discovered as the result of a two-year prospecting program based on government geological maps. Later that year, Corporation Falconbridge Copper optioned the Rea Gold property. In early 1985, Falconbridge Copper proposed a nine-hole, 2400-metre drill program to test targets on the Rea Gold, Austin-Apex (MINFILE 082M 276) and Kamad (MINFILE 082M 277) options. Four drillholes totalling 1750 metres were planned for the Rea Gold property. Only two of the nine diamond drill holes were completed, neither of which intersected the target horizon. Falconbridge Copper later dropped the options on the Kamad and Austin-Apex properties but retained their option on the Rea Gold property.

A second mineralized horizon, the Silver zone, was discovered in mid-1985. In 1986, widely spaced drillholes intersected narrow, often high-grade mineralization over a 3.2-kilometre strike length. Later that year, Falconbridge Copper further delineated the new zone by completing 12 NQ diamond drill holes totalling 3253.4 metres.

Between 1985 and 1989, Esso Minerals Canada conducted exploration on the Kamad property to the immediate south of the Rea Gold occurrence. During this time, Esso Minerals completed geological mapping, soil sampling and diamond drilling on the property. Exploration efforts resulted in the discovery of the K-7 massive sulphide lens. Homestake Canada Limited acquired Esso Minerals Canada’s interest in the Kamad property in 1989 and completed diamond drilling, backhoe trenching and electromagnetic geophysical surveying on the Kamad 7 and 8 claims.

In 2000, after Homestake Canada Limited allowed the Kamad property to lapse, Paul Watt staked the Extra High property over the northern portion of the Kamad property containing the K-7 showing. That year, Watts completed an orientation soil sampling program with limited prospecting and rock sampling and a soil traverse across favourable stratigraphy.