The D zone, which is located 800 metres east of the Big Missouri deposit, lies within south-southeast striking, moderately dipping andesite, agglomerate and lapilli tuff, with interbedded cherty tuff of the Lower Jurassic Unuk River Formation. (See Big Missouri - 104B 046 for enhanced geology). The mineralized zone is on the northwest limb of a shallow amplitude, anticlinal structure. The fold axis trends northeast, plunges 15 to 22 degrees southwest, and has a 20 to 30 degree dipping northwest limb. The rocks are cut by north-northwest and northeast trending, steeply dipping faults. Open pit production commenced at D Hill in late August 1988.

The D zone occurs within the Lower Horizon which consists of green plagioclase-amphibole andesite agglomerate and lapilli tuff with lesser bleached andesite and cherty tuff. Three one to 5-metre-thick carbonaceous cherty tuff beds, called D, E, and F, are separated by 6 to 8 metres of altered andesite, commonly with quartz-sulphide stringers. The andesite is pervasively sericitized and weakly to intensely silicified (bleached). Pyrite is commonly pseudomorphic after amphibole. Quartz, carbonate and carbonaceous veining are common.

Mineralization, consisting of pyrite, sphalerite, galena, chalcopyrite, argentite, tetrahedrite, and pyrargyrite, occurs as disseminations, lenses, pods, and stringers within the cherty tuffs and footwall and hangingwall andesite tuffs. Gold occurs as discrete grains of electrum along fractures and grain boundaries of sulphides and in the quartz-carbonate-sericite matrix. Relatively coarse-grained electrum occurs in pyrite and sphalerite. Silver minerals, consisting of acanthite, native silver and freibergite, occur as complex intergrowths with galena, siderite and chalcopyrite along narrow fractures, as rims on galena and chalcopyrite or as interstitial fillings in the gangue minerals.

Production through 1988-1989 was 384,000 tonnes of ore grading 1.2 grams per tonne gold and 10.0 grams per tonne silver. In 1991, geological reserves were 150,000 tonnes grading 1.2 grams per tonne gold and 10.0 grams per tonne silver (D. Alldrick, PhD Thesis, UBC, 1991).

Work History

This property is located on the east side of Silver Creek, about 21 miles south of Mount Dilsworth, adjoining on the east the E. Pluribus and Golden Crown claims of the Big Missouri group.

The showings were originally staked in about 1909 and were held by different prospectors for about 8 years during which time no assessment work was done. Robert Martin, one of the original locators, and a Dr. Carter bought the Little Joker claim in 1917 and located 2 adjoining claims, the Mineral Hill and Midas. Late in 1917 the claims were bonded to Messrs. Welsh, Fetter, Carlton, and Carter, of Seattle, Washington who formed the Mineral Hill Partnership. Additional claims were staked, bringing the total to 7. These are the Midas Lake Fr., Midas, Mineral Hill, Mystery, Little Joker, Lookout, and Pass Fr. (Lots 3900-3906). Development work during 1918 and 1919 included numerous trenches and 700 feet of underground work in one adit. The partnership formed Mineral Hill Mines Limited in January 1920, however, very little work was done. In 1934 a small shipment of ore was made by a Mr. Watkins and associates. John Hovland, owner of the adjoining Unicorn group, made a small shipment from the Little Joker claim in 1950.

In 2011, Ascot Resource drilled 12 holes into the D zone (Assessment Report 33267). In 2011, drill results identified several subhorizontal mineralized zones that can be traced across all sections. P11-117 and 118 were the first holes of the season and although results were low especially in 117 which returned no significant values, both holes contained siliceous breccia and altered andesite that defined a continuous zone. Several Premier Porphyry dikes were noted too. P11-118 yielded 0.32 gram per tonne gold and 1.9 grams per tonne silver over 9.10 metres (Assessment Report 33267). Other results were similar with wide zones of 1.0 gram per tonne gold plus with occasional spikes in mineralization including 9.85 gram per tonne gold over 1.34 metres in P11-121 and wide intervals such as 0.59 gram per tonne gold over 123.0 metres in P11-123 (Assessment Report 33267). The best result was rom P11-128 which returned 1.44 grams per tonne gold and 60.0 grams per tonne silver over 62.35 metres at 152.65 metres including 22.90 grams per tonne gold and 1545 gram per tonne silver over 2.0 metres which contained electrum identified in drill core (Assessment Report 33267). Interpretation indicates several large lenses of mineralization that can be traced consistently between drill holes and across adjacent sections.

In 2012, Ascot Resource drilled 5 holes. The results were good, and the best intersection was 23.00 metres grading 1.70 grams per tonne gold and 32.9 grams per tonne silver (Ascot Resources Press Release, August 1, 2012).

See Big Missouri (104B 046) for related and specific historical work. See also Yellowstone (104B 039) and Premier (104B 054) for related details of the Dilworth and Premier properties that and include the D occurrence.