The Red Cliff mine is on the west bank of Lydden Creek, immediately west of the confluence of American Creek and the Bear River, 19 kilometres north of Stewart. The portal to a lower, 425-metre-long access tunnel (700 level) is at an elevation of 146 metres and is located on the east bank of Lydden Creek, about 700 metres west of the Stewart highway. Two portals (North and South) access the 1000 level and are located on the west bank of Lydden Creek, about 500 metres north-northwest of the portal of the lower tunnel. A fourth portal (Upper portal) lies about 30 metres above the North and South portals.
The area is underlain predominantly by north striking, west dipping andesitic tuffs, agglomerates and minor flows of the Lower Jurassic Unuk River Formation (Hazelton Group) (Bulletin 58; 63). Immediately east of Lydden Creek, a conformable body of amygdaloidal feldspar porphyry, containing phenocrysts of feldspar and augite, may represent a sill or a flow. Tertiary(?) quartz monzonite, diorite and hornblende porphyry dikes are common. These trend northwest and northeast and are part of the Portland Canal dike swarm (Bulletin 58). The area is intensely fractured and faulted. North trending, west dipping dipslip faults are most conspicuous and appear to be younger than east trending faults.
Mineralization comprises irregular veins and pods of quartz, pyrite, chalcopyrite and minor sphalerite. The orebodies, irregular and lenticular, are commonly enclosed in weakly developed sericitic alteration. The largest orebody, 76 metres long and averaging 6 metres in width, occurs on the 700 level.
Most of the mineralized pods appear to lie along locally east trending, steeply dipping shears that transect all rock types except the diorite dikes. The mineralization is most conspicuous adjacent to, and on the hangingwall of, a prominent north trending, west dipping fault along Lydden Creek.
Estimated reserves for the Red Cliff deposit are reported to be 18,856 tonnes of sorted ore grading 3.19 per cent copper and 2.8 grams per tonne gold (J.L. Parker, 1912; cited in Assessment Report 17465, page 35).
WORK HISTORY
The Red Cliff group (Red Cliff, Montrose (104A 033), Mount Lyell (Lot 77), Little Pat (104A 062), Waterloo (104A 033) and Mac and Dot Fractions) were originally held by Lydden, Pederson, McDonald and Peardon who did some open cutting and drove tunnels in 1908. Apparently, other zones were discovered at the same time (Montrose, Waterloo). That year the property was sold to A.E. Smith, who formed the Red Cliff Mining Company. Between 1908-12, about 2385 metres of underground development was carried out on five(?) levels on the Red Cliff mineralization, including four portals, a long access tunnel and raises. The Red Cliff mine was the first significant mine in the Stewart area; it was linked to Stewart by road and rail. About 200 tonnes of ore grading 5 per cent copper was stockpiled in 1910; an additional 1.4 tonnes were shipped to the Tyee smelter and yielded 8.25 per cent copper, 83.7 grams per tonne silver and $5 per ton gold (1910 prices). In 1912, upon completion of the railway, a further 1133 tonnes of ore were shipped to the Tacoma smelter and another 2030 tonnes was placed on ore dumps. A total of 2411 grams of gold and 40,100 kilograms of copper was recovered. The mine closed in 1912. The property remained idle until 1921, when Trites, Woods and Wilson purchased the property and carried out minor work on the Montrose and Waterloo zones. Little further work was reported until 1939, when H.D. Haywood purchased the claims from the estate of Wilson. That year a camp and trail were built and during 1939 and 1940 Haywood worked on the Montrose zone; about 40 tonnes of ore were shipped from the Montrose zone during this period. In 1941, 10 tonnes (averaging 9.23 per cent copper, 1.09 per cent zinc, 8.9 grams per tonne gold and 75.4 grams per tonne silver) was high graded from the 700 level(?) of the Red Cliff deposit and 19.3 tonnes of ore was high graded from the Montrose zone. In 1946, the Yale Mining Company, Limited optioned the property and sampled the Montrose and Waterloo zones. In 1950, Yale Lead and Zinc Mines Limited completed about 600 metres of drilling on the Montrose(?) zone. n 1959, Oro Fino Mines Ltd. optioned the property; no work was reported. In 1968, International Mogul Mines Limited acquired the property through amalgamation of several companies, including Yale Lead and Zinc. In 1972, Citex Mines Ltd. acquired a three year lease on the property from International Mogul and subsequently entered into an agreement with Adam Milling Ltd. The latter company built a 110 tonnes-per-day mill at the mouth of Bitter Creek and reopened the Red Cliff mine in April 1973. The 700 level was rehabilitated, and open stoping commenced. However, due to unsafe conditions, the Ministry of Mines closed the mine in September 1973. Apparently, 3768 tonnes of ore were shipped to the mill from the mine and old dumps (this tonnage may include some ore from the Roosevelt deposit (104A 069)). Some drilling was also reported in area of the Red Cliff deposit that year. Little further work has been reported since 1973. In the late 1970s, limited work was done underground and, in 1979, Page and Skimming carried out sampling on the Red Cliff, Montrose and Waterloo zones. In 1987, Joutel Resources Ltd. entered into a joint venture agreement with B.L. Carlson and V.N. Harbinson on the Red Cliff claim group and staked two grid claim blocks. That year Joutel conducted a comprehensive program, focusing mainly on the Montrose and Waterloo zones, comprising trenching, geological mapping, soil, silt and rock sampling and diamond drilling (six holes totalling 1007 metres) on the Montrose and Ridley Road zones.
In 1988, Joutel drilled four holes with no data available to the later owners regarding azimuths, lengths and dips.
In 1990, Joutel drilled 614 meters in three holes testing the Montrose and Red Cliff Zones. Several holes drilled in the 1987 and 1990 programs returned intercepts of 1.72 grams per tonne gold over 14.48 metres including 9.31 grams per tonne gold over 1.70 metres, and 1.17 grams per tonne gold over 16.89 metres including 4.82 grams per tonne gold over 2.29 metres for the Montrose Zone (as reported by Lawrence Dick, 2014).
In 2007, a total of 8,555 meters of drilling was completed in 41 diamond drill holes on drill roads constructed during the field season. Drilling was primarily conducted in the area of the Red Cliff and Montrose Zones. Some of the drilling intersection highlights on the Red Cliff Zone include values up to 3.51 per cent copper and 2.2 grams per tonne gold over 4.02 metres in DDH-2007-RC-7, and 3.61 per cent copper and 1.76 grams per tonne gold over 10.73 metres in DDH–2007-RC-56 (as reported by Lawrence Dick, 2014).
In 2009, Decade completed 5,227 metres of diamond drilling in 36 holes to test the area of the Montrose Zone. Drill intersection highlights include 32.52 metres of 7.53 grams per tonne gold and 0.17 per cent copper in DDH-MON-2009-16, and 55.18 metres of 9.64 grams per tonne gold and 0.21 per cent copper in DDH-MON-2009-6 (as reported by Lawrence Dick, 2014).
In 2010, Mountain Boy optioned the property to Decade Resources Ltd. and the exploration program completed during the field season totaled 12,572 meters of drilling in 81 holes. Drill intersection highlights include 13.42 metres of 13.42 grams per tonne gold and 0.37 per cent copper in DDH-MON-2010-27, and 25.91 metres of 10.94 grams per tonne gold and 0.22 per cent copper in DDH-MON-2010-31 (as reported by Lawrence Dick, 2014). These intersections were considered highly-potential for further exploration and mineralization definition and provided the impetus for further exploration on the property.
In 2011, the Joint Venture Partners (Mountain Boy and Decade) completed 6,166 meters in 44 holes. Drill intersection highlights include 15.86 metres of 12.04 grams per tonne gold and 0.40 per cent copper in DDH-MON-2011-15, and 12.80 metres of 18.01 grams per tonne gold and 1.52 per cent copper in DDH-MON-2011-22 (as reported by Lawrence Dick, 2014). These intersections are core lengths and true widths could not be calculated since structural data was not conclusive at the time of drilling.
In 2012, the Joint Venture partners completed 13,240 meters of diamond drilling in 73 holes. Drill intersection highlights include 14.02 metres of 14.86 grams per tonne gold and 0.22 per cent copper in DDH-MON-2012-24 and 35.06 metres of 7.83 grams per tonne gold and 0.42 per cent copper in DDH-MON-2012-62 (as reported by Lawrence Dick, 2014). Again, these results indicated that substantial potential exists in the gold-bearing hydrothermal system and that further drilling and/or underground workings are required to obtain a relevant mineralization resource.
In 2012, Mountain Boy Minerals Ltd, with joint venture partner Decade Resources Ltd, drilled 13,240 meters in 73 holes at the past producing Red Cliff copper-gold-silver-zinc property (MINFILE 104A 037). Drill intersection highlights include 14.02 metres of 14.86 grams per tonne gold and 0.22 per cent copper in DDH-MON-2012-24 and 35.06 metres of 7.83 grams per tonne gold and 0.42 per cent copper in DDH-MON-2012-62 (as reported by Lawrence Dick, 2014). Most of the drilling focused on the Montrose zone (MINFILE 104A 033) approximately 1 kilometre north of the historic Red Cliff underground workings and approximately 20 kilometres north of Stewart. Drilling has yielded multiple significant gold intercepts proximal to historic workings including minor amounts of visible gold.
In 2016, Decade carried out geochemical surveys, rock sampling and a small diamond drilling program.
In 2017, Decade Resources Ltd. reported rock sampling results of 19.9 grams per tonne over 4 metres for the Waterpump zone at the Red Cliff gold-copper project (Exploration in BC 2017, page 30). Drill core from the Waterpump zone is described as having sphalerite-galena-chalcopyrite veins in the wall of a breccia that contains quartz, pyrite, and minor chalcopyrite over 15 to 20 metres true width. Visible gold has been observed in sphalerite-galena-chalcopyrite veinlets and in quartz-pyrite veinlets. Drill result highlights for the Montrose zone include 14.93 grams per tonne gold over 8.38 metres and 9.5 grams per tonne gold over 10.98 metres (Exploration in BC 2017, page 30).
In 2018, Decade Resources Ltd conducted a 53-hole, 11,000 metre diamond drilling program on the Red Cliff project. Drilling results for the Waterpump zone included 4.54 metres of 12.11 grams per tonne gold and 7.26 metres of 10.6 grams per tonne gold (Exploration in BC 2018, page 128).
In 2018, Decade reported that drilling has completed 53 holes to date on both the Waterpump and Montrose zone. Of the sixteen holes completed on the Montrose zone, a total of 10 holes contain visible gold in the core associated with the chalcopyrite-pyrite stockwork. Sulphide mineralization including sphalerite and galena veinlets form an envelope to the chalcopyrite-pyrite mineralization and extend the width of the potential gold bearing zones. Intersection of 43.91 grams per tonne gold over 7.47 metres was reported (Decade Resources, Press Release July 24, 2018). Decade's plan is to block out the recently indicated high grade zone that is a minimum plus100 meters long and approximately 400 metres down-dip within the 400 metre of structure length drill tested to date. Width of the Montrose zone in this area appears to be from 8 to 22 metres based on the modelling. Mineralization is reported to be open to depth and along strike.
Also refer to Montrose (104A 033) for related details.
