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File Created: 24-Jul-1985 by BC Geological Survey (BCGS)
Last Edit:  28-Mar-2022 by Nicole Barlow (NB)

Summary Help Help

NMI 104B1 Au6
BCGS Map 104B020
Status Prospect NTS Map 104B01E
Latitude 056º 07' 11'' UTM 09 (NAD 83)
Longitude 130º 01' 09'' Northing 6219872
Easting 436635
Commodities Gold, Silver, Lead, Zinc, Copper Deposit Types I05 : Polymetallic veins Ag-Pb-Zn+/-Au
H05 : Epithermal Au-Ag: low sulphidation
Tectonic Belt Intermontane Terrane Stikine
Capsule Geology

The Unicorn occurrence, which is located 700 metres north-northeast 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 occurrence, which lies immediately west of the north trending Union Creek Fault, is located within an alteration zone characterized by sericite, chlorite, quartz, calcite, epidote and pyrite. The altered zone trends north-northwest for about 500 metres and varies from 70 to 120 metres wide. Mineralization consists of disseminated pyrite, arsenopyrite, sphalerite, galena, chalcopyrite and fine native gold. A sample of the zone assayed 6.2 grams per tonne gold, 137 grams per tonne silver, 1.0 per cent lead, and 4.0 per cent zinc (Minister of Mines Annual Report 1933). A 1.5 metre chip sample assayed 3.77 grams per tonne gold and 0.7 gram per tonne silver (Cochrane, D.A., 1974).

The altered zone is cut by east-striking south-dipping and northwest-striking west-dipping mineralized quartz-calcite veins. Southeast-striking lamprophyre dykes cut some of the veins. See the A Vein (104B 145).

In 2010 the Unicorn zone of Ascot Resources, encompassed the Unity zone area, and was characterized by low-grade gold mineralization and a typical silica-sericite-pyrite- silica alteration assemblage. Silica occurs as a prominent quartz stockwork with very weak siliceous alteration on the margins of the host andesite fragments. Pyrite is pervasive and occurs as fine disseminations in most rocks with increasing abundance and size with increasing silica. Fine-grained pale tan to grey coloured sericite is common and is observed as wispy to irregular fracture fill with silica around angular fragments of andesite. Carbonate is minor and variable, and occasional sphalerite occurs as small red-brown coloured spots or as thin veinlets, often with carbonate. Hole P10-88 yielded a 66.47 metre drill interval that assayed 0.39 gram per tonne gold (Assessment Report 32357).

The Unicorn zone is described as a west dipping, structurally controlled epithermal system with previously unrecognized extensive high level “Premier porphyry” dikes and stocks. The Premier porphyry is a two-feldspar rock of granodiorite composition. The Unicorn zone has now been traced by drilling for a strike length more than 1,350 metres and remains open at both the south and north ends and has been traced to depths more than 250 metres from surface and remains open at depth. This zone has been tested by a total of 27 holes spaced 50 to 200 metres apart. The zone routinely is between 100 and 200 metres in width, containing anomalous gold values ranging from 100 to 2,000 parts per billion gold, with higher-grade zones within this broad epithermal envelope.

Drilling at the Unicorn Zone in 2011 occurred in a flat area to the east of the Union Creek Fault, and across a zone over 500 metre north-south and up to 200 metres wide. Several bodies and dikes of Premier Porphyry were observed throughout the Unicorn area, often in great abundance and frequently near the mineralized zones. Quartz-sericite altered andesite is observed at the surface and extends to below the drilled limit. Assay results in the middle portion are low but over wide intervals such as drill hole P11-189 which was mineralized over its entire length, 0.48 gram per tonne gold over 197.51 metres (Assessment Report 33267) hosted in variably altered andesite plus with several short zones of siliceous breccia.

Work History

Four claims, the Unicorn, Unicorn No. 2, Unicorn No. 3, and Unity (Lots 4534-4537), were apparently located by John Hovland, of Hyder, Alaska, prior to 1919. During 1919-1920 the claims were under option to J.B. McDonald and consider- able work was done, including open cutting and 700 feet of diamond drilling; the option was given up late in 1920. Messrs. Trites and Wilson optioned the Unicorn and Big Missouri groups in 1922; some trenching was done on the Unicorn property. The original claim group was Crown-granted in 1925 to Messrs. Hovland and Watkins. By 1928 the property had been expanded to include the Good Hope (Lot 4539), Snow King (Lot 4539), and four fractional claims.

Unicorn Mines, Limited was incorporated in January 1929 to acquire the property. Development work was carried on each year until about 1936. Work to this date totalled some 1,200 feet of drifting and crosscutting in 4 adits. Some diamond drilling was done in 1935. No further activity was reported until 1948 when the company, with John Holland as managing director, resumed work on the property. Number 3 adit, which had been driven parallel to and a short distance east of the Unity zone was advanced 9 metres to a point 183 metres from the portal. Three short crosscuts to the west of the tunnel have cut the Unity zone with the intent of exploring the intersection of the Unity with an easterly striking shear zone (A zone). This objective had not been reached when work ceased in 1950.

Tournigan Mining Explorations Ltd. by an agreement of 1974 acquired an option to purchase claims from Unicorn Mines, Limited. Work on the property during 1974 and 1975 included geological mapping, a geochemical rock survey (105 samples), sampling in No. 3 adit, and trenching. Asarco Incorporated collected 46 rocks on the Unicorn group under option from Tournigan.

Tapin Copper Mines Limited optioned the property from Tournigan by an agreement dated May 25, 1976. Work by Tapin during 1976 included an induced potential survey over the Unicorn property. The Tapin option agreement was subsequently abandoned.

Tournigan optioned its interest in the property to Western Mines Limited by a 1978 agreement.

Westmin Resources Limited began work in the area during 1979; by 1988 a total of 8,389 metres of diamond drilling in 144 holes had been completed. In 1991 Westmin conducted a significant Airborne magnetic and electromagnetic survey totaling 760 kilometres that covered over 60 more occurrences, mainly to the south. During 1995, Westmin mapped the surface geology of the Martha Ellen area, and re-examined core from some of the earlier drill holes.

Ascot Resources Ltd conducted exploration on the Dilworth Property in 2007 and 2008 and subsequently acquired the Premier Gold Property from Boliden Ltd under the terms of a 2009 option agreement.

The 2008 exploration program of Ascot Resources Ltd conducted on the Dilworth property included diamond drilling, surface rock sampling, geological mapping, a 428.2-kilometre airborne Mag/EM survey and airborne radiometric survey, geochemical sampling including contour sampling, a soil grid and stream sediment sampling of all streams on the west and east sides of the property (Assessment Report 31000). Diamond-drilling in 2008 totalled 10885.1 metres in 63 holes. Only the airborne survey extended off the Dilworth property to the south covering parts of the Big Missouri (104B 046) and further south to the Premier (104B 054).

During 2009 (Assessment Report 31489) and 2010 (Assessment Report 32357) all exploration activity by Ascot was conducted on the Premier and Big Missouri Properties. In 2009 a total of 7465.3 metres were drilled in 48 holes into multiple zone including 3rd, Premier, Power, Hope, Loui's, S1, Northstar, Province, Martha Ellen, Montana, Rambler, Silver Tip, Unicorn, Golden Crown and Mudstones. A grab sample from the end of a tunnel assayed 19.41 grams per tonne gold and 22.5 grams per tonne silver (Kirkham, G. (2012-06-18): Technical Report on the Resource Estimate for the Premier Gold Property).

In 2010 a total of 21,742 metres in 68 holes were drilled into a number of zones from the combined Dilworth and Premier properties of Ascot including: Unicorn, A-Vein, S1, Creek, Calcite Cuts, Province, Day, Martha Ellen, Sparky, Bee, Forty Nine and Gerrys zones. In 2009, 3 Ascot drilled 3 of its 48 holes on the Unicorn zone. In 2010, Ascot Resources, drilled 22 of its 68 holes on the Unicorn zone, which spanned about 700 metres north to south and encompassed the Unity zone location.

In 2011, Ascot Resources Ltd drilled 36,318 metres on the Big Missouri and Dilworth properties. Drilling was also completed in the Province (MINFILE 104B 147) and Unicorn (MINFILE 104B 044) areas following up lower grade gold intercepts. Early drill results from Unicorn yielded 62.61 metres from hole PR-11-158 grading 3.74 grams per tonne gold and 4.4 grams per tonne silver (Exploration in British Columba, 2011). Several drill holes intersected visible gold and electrum.

In 2012, Ascot Resources Ltd conducted a significant drilling program spread across three areas: Big Missouri (MINFILE 104B 046), Martha Ellen (MINFILE 104B 092) and Sparky zone in the Dilworth (104B 039). A resource estimate for the Big Missouri area utilizes drilling data from 2009-2011 was released in May.

In 2013, Ascot Resources completed 25,742 metres of drilling in 145 holes spread between Premier (104B 054), Martha Ellen (104B 092), Province, S1 and Unicorn zones. Drilling successfully expanded and confirmed bulk-tonnage and high-grade underground gold-silver targets. Ascot released an increased resource estimate for the Big Missouri, which included Martha Ellen (104B 092) data.

In 2014, Ascot Resources Ltd. continued drilling at the Premier and Big Missouri gold projects. Drilling of a multiphase program consisted of 36,672 metres in 169 holes. The work identified a new area of mineralization at Big Missouri before focusing on zones around Premier. A resource estimate for the Big Missouri (including the Dilworth, Martha Ellen and Big Missouri deposits) was released this year.

For recent work history and related information on the Premier-Big Missouri-Dilworth project see Yellowstone (104B 039), Big Missouri (104B 046) and Premier (104B 054) areas that were held as a single entity in the 2000s by Boliden and Ascot Resources.

EMPR AR 1919-77; 1920-63; 1922-84; 1923-83; 1925-103; 1928-115,116; *1929-109; *1930-114,115; 1931-47; 1932-60,61; *1933-59,60; 1935-G48; 1948-70; 1949-75; 1950-78
EMPR BULL 58, p. 126; 63
EMPR EXPL 1975-179,180; 1976-179,180; 1978-257; 1979-280; EMPR 2009-19; 2010-50; *2011-34,35; 2012-50; 2013-59; 2014-103; 2015-133; 2016-18,164; 2017-30,137
EMPR FIELDWORK 1978, p. 105; 1980, pp. 201-209; 1982, pp. 182-195; 1983, pp. 149-164; 1984, pp. 316-341; 1985, pp. 217,218; 1986, pp. 81-102
EMPR GEM 1974-331
EMPR OF 1987-22
EMPR PF (*RPT by D.R. Cochrane (1974): Unicorn Project)
EMR MP CORPFILE (Tournigan Mining Explorations Ltd.)
GSC MAP 9-1957; 1829; 307A; 315A; 1418A
GSC MEM 132; *175, p. 170
GSC P 89-1E, pp. 145-154
CIM SPEC. Vol. 37, pp. 202-215
PR REL Ascot Resources, Nov. 23, 2009; *Oct. 12, 2010; Jun.23, *Oct.12, Nov.23, Dec.17, 2012
Brown, D. (1987): Geological Setting of the Volcanic Hosted Silbak Premier Mine, M.Sc. Thesis, University of British Columbia (in Property File 104B 054)
Galley, A. (1981): *Volcanic Stratigraphy and Gold-Silver Occurrences on the Big Missouri Claim Group, Stewart, British Columbia, M.Sc. Thesis, University of Western Ontario
Christopher, P.A. (2009-08-03): Technical Report on the Premier Gold Project
*Kirkham, G. (2012-06-18): Technical Report on the Resource Estimate for the Premier Gold Property
Kirkham, G. (2012-08-20): Revised Technical Report on the Resource Estimate for the Premier Gold Property
Puritch, E. (2013-03-27): Technical Report and Resource Estimate for the Big Missouri and Martha Ellen Deposits, Premier Gold Property
Rennie, D.W. (2018-06-22): Technical Report on the Premier-Dilworth Project
Rennie, D.W. (2019-01-17): Technical Report on the Premier Project
Bird, S.C., Meintjes, T. (2020-02-28): Resource Estimate Update for the Premier Gold Project, Stewart, British Columbia, Canada
Ascot Resources Limited (2020-05-22): Premier & Red Mountain Gold Project Feasibility Study NI 43-101 Technical Report, British Columbia
EMPR PFD 19141, 19142, 19143, 19144