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

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NMI 104I7 Cu1
Name DISCOVERY, TURN (DISCOVERY), TURNAGAIN (DISCOVERY), TURNAGAIN, COBALT, PYRRHOTITE, CUB, AGAIN, TURNAGAIN NICKEL, HORSETRAIL Mining Division Liard
BCGS Map 104I046
Status Prospect NTS Map 104I07W
Latitude 058º 28' 34'' UTM 09 (NAD 83)
Longitude 128º 49' 40'' Northing 6481732
Easting 510044
Commodities Nickel, Cobalt, Copper, Chromium, Tungsten, Molybdenum Deposit Types M05 : Alaskan-type Pt+/-Os+/-Rh+/-Ir
Tectonic Belt Intermontane Terrane Cache Creek, Cassiar, Quesnel
Capsule Geology

The Turn (Discovery) occurrence is located about 70 kilometres east of Dease Lake.

The prospect is hosted in a Later Triassic Alaskan-type ultramafic intrusive complex. This zoned complex consists of a dunite core and surrounding peripheral peridotites, pyroxene-rich peridotite, and olivine pyroxenite. The complex has maximum dimensions of 3 by 8.2 kilometres and was intruded in the Lower Jurassic (and earlier(?)) into Upper Paleozoic(?) and/or Triassic(?) metavolcanic and metasedimentary rocks of the Quesnel Terrane. It is in faulted contact on the east and north with slate and phyllite of the Ordovician to Mississippian Road River Group (Ancestral North America).

Concentrations of iron-nickel-copper sulphides occur in several places in the ultramafic rocks flanking the central dunite. The dunite is conspicuously barren of primary sulphides. Primary sulphide occurs as disseminated blebs, interconnecting blebs (net-texture) and massive bands up to a few centimetres thick.

Falconbridge Nickel Mines optioned the Cobalt and Pyrrhotite claims in 1966 and then acquired the Turn 1-76 claims. Work from 1966 to 1973 included geological surveys, airborne and ground magnetometer and electromagnetic surveys, and 2742 metres of diamond drilling in 28 holes and 123 metres of packsack-drilling in 11 holes. Maps from 1972 Assessment Report 3735 show that these diamond-drill holes were put down mainly on or in the vicinity of the Northwest (104I 051), Horsetrail (104I 119) and Fishing Rock (104I 120) occurrences. The Turn (Discovery) has one nearby packsack hole and the Cliff (104I 118), which occurs at the east end of the complex, was examined by 4 packsack drillholes. The Agnes (Davis) showings (104I 038 and 117) occur a few kilometres north of the Northwest showings within the complex and were apparently worked initially by Union Miniere Explorations and Mining in 1971. In 1986, some of the Falconbridge core was resampled by Supreme Resources Limited for gold and platinum and this work provides most of the available description for the Falconbridge drillholes (see Assessment Report 16458). Also, in 1986, Equinox Resources Limited held claims that covered the Agnes (Davis), Discovery, Cliff, Northwest and possibly the Fishing Rock showings. Equinox conducted a program to evaluate platinum and palladium potential throughout the complex but primarily in the Cliff and Northwest occurrence areas. Bren-Mar Resources conducted drilling and metallurgical work in 1997 and 1998.

Specifically, at the Discovery showing, net textured pyrrhotite with minor amounts of chalcopyrite and pentlandite are hosted in serpentinite and associated with magnetite and clinopyroxenite. The showing occurs in an area along the Turnagain River that is about 1 by 5 metres in size. The rocks are highly sheared in this area due to a shear zone inferred to be paralleling the river (Clark, 1975 and Assessment Report 15994).

Detailed reports often describe mineralization encountered in drillholes and elsewhere as pertaining to the Turn property in general and fail to report with which particular showing it may be associated. The following is such information and is included with this occurrence description, although it may properly belong to one or all those showings listed above.

Primary sulphides occurring in the ultramafic complex include pyrrhotite, pentlandite, chalcopyrite and bornite. Oxides intimately associated with these sulphides are chromite, ilmenite and magnetite. Non-primary sulphides in the complex include violarite, valleriite, molybdenite, pyrite, marcasite and possibly mackinawite (Clark, 1975).

Clark reports that high concentrations of nickel-rich sulphides, assaying about 1 per cent nickel, are normally only a few centimetres thick. Moderately high concentrations, assaying more than 0.4 per cent nickel, attain thicknesses of at most 20 metres (Clark, 1975).

Chromite is the most widespread oxide mineral but is not considered to occur in economic quantities. It normally occurs as fine-grained disseminations, but locally occurs as wispy, schlieren-like concentrations in dunite and as massive to near massive layers. Chromite concentrations are found only in dunite. Massive layers have a length of up to 10 metres and a maximum thickness of about 2 centimetres (Canadian Journal of Earth Sciences, Volume 15, No.12, 1978).

Molybdenite associated with pentlandite-rich pyrrhotite was found over less than a metre of drill core and low-grade intersections of tungsten (scheelite) were also encountered (Assessment Report 3735). Values for gold, platinum and palladium were typically low (Assessment Reports 15994 and 16458).

During 1996 and 1997, Bren-Mar Resources Ltd. completed a 14-hole, 2467 metre diamond drilling program; all holes intersected nickel-bearing sulphide mineralization. Mineralization is associated with the olivine pyroxenite and pyroxenite rocks within an ultramafic complex of Late Triassic age, approximately 8 kilometres long and up to 3 kilometres wide. Sulphides have been intersected over a strike length of 3.7 kilometres, a width of 2 kilometres and up to 300 metres in depth. Three of 14 holes drilled in the past two years returned broad intercepts of nickel and cobalt, from 90 to 260 metres averaging 0.24 to 0.31 per cent nickel and 0.016 per cobalt. Metallurgical testing, including flotation and leaching studies, has been initiated. The company's geologic model and exploration target is a bulk tonnage (>225 million tonnes) nickel-cobalt deposit. Bren-Mar Resources will proceed with detailed metallurgical studies, including mineralogical analyses, magnetic separation, flotation and pressure leach studies.

Canadian Metals Exploration Ltd. carried out an induced polarization study during 2002 covering much of the complex and drilled three diamond-drill holes. Drilling in 2002 occurred in the vicinity of the Horsetrail occurrence (104I 119).

In 2007, hole 07-206 was drilled to test the area underneath the Discovery outcrop in the area of holes 97-06 and 97-07 and to intersect the ultramafic contact. Hole 07-206 intersected variably serpentinized and graphitic wehrlite with visual sulphide estimates ranging from 0.5 to 3.0 per cent to a depth of 98.00 metres. A faulted contact separated this wehrlite from sheared metasediments with minor interfingered wehrlite to a depth of 126.50 metres. Serpentinized wehrlite with 2.0 per cent sulphides and minor metasediment inclusions followed to a depth of 155.50 metres. From this depth to 324.50 m was a long sequence of olivine clinopyroxenite and clinopyroxenite with minor wehrlite while sulphides generally remained above 1.5 per cent. At 324.50 metres a faulted contact between sulphide-poor wehrlite and sheared, graphitic, quartz-rich phyllite was encountered. Phyllite was intersected until end of hole at 358.75 metres. Analyses yielded total nickel values of 0.29 per cent from 29.55 to 84 metres and 0.40 per cent from 244 to 272 m and platinum+palladium values of 384 ppb from 260 to 268 metres (Assessment Report 29748). Hole 07-206 extended the mineralization encountered in holes 97-06 and 97-07 and delineated the ultramafic contact.

In 2007, drill hole 07-203 was initiated in order to test the area of deep overburden between the Horsetrail mineralization and the Discovery outcrop to the east. The hole intersected variably serpentinized dunite and wehrlite with no to trace sulphides through its entire length, save for a short, intensely serpentinized dunite with 0.5 per cent sulphides from 406.45 metres to 413.80 metres. Analyses yielded no significant results.

Hole 07-203 failed to indicate continuity of mineralization between the Horsetrail and Discovery outcrop while hole 07-206 intersected encouraging nickel grades at depth below the Discovery outcrop.

See Turnagain Nickel (Horsetrail (104I 119)) for further details of the Turnagain property, including geology, work history and bibliography.

Bibliography
EMPR AR 1966-22; 1967-28
EMPR ASS RPT 2056, *3735, *4097, 8055, *15994, *16458, 24911, *25475, *29748, 30367, 32008, 32767, 37832, 39922
EMPR EXPL 1979-484; 1987-384,385; 1996-B12; 1997-16; 1999-19-31
EMPR FIELDWORK 2001, pp. 365-376
EMPR GEM 1969-49; 1970-40; 1971-46; 1972-545; 1973-512
EMPR GEOFILE 2000-2; 2000-5
EMPR INF CIRC 1998-1, p. 29
EMPR OF 1989-18; 1996-11
EMPR PF (Kilburn, L.C. (1967): Report on Turnagain Copper-Nickel Prospect to December 1967; Bren-Mar Resources Ltd. Website (March 2000: Turnagain Project; Canadian Metals Exploration Limited Research Profile (2003): Drilling Set to Resume in Mid February 2003 as Turnagain Nickel/PGM Project Enters Advanced Stage of Exploration)
GSC OF 610; 2262; 2779
GSC BULL 504
GSC MAP 9-1957; 29-1962; 1418A; 1712A
GSC P 78-1A, pp. 25-27
CJES *Vol.15, No.12, 1978, pp. 1893-1903; *Vol.17, No.6, 1980, pp. 744-757
GCNL #141(July 23), #199(Oct.16), #208(Oct.29), 1997; #163(Aug.25), 1998
N MINER May 4, 1998
PR REL Canadian Metals Exploration Ltd., Sept.17, Oct.24, Nov.14, Dec.13, 2002; Feb.20, 2003
*Clark, T. (1975): Geology of an ultramafic complex on the Turnagain River, northwestern British Columbia. Ph.D. thesis, Queen's University, Kingston, Ontario
Nixon, G.T. (1998): Ni-Cu Sulfide Mineralization in the Turnagain Alaskan-Type Complex: A Unique Magmatic Environment, article in Bren-Mar Resources Ltd. Website, March 2000, 14 pages (copy in Property File 104I 014)
Simpson, R.G. (2007-03-29): Mineral Resource Update – Turnagain Nickel Project
Kulla, G. (2007-09-25): NI 43-101 Technical Report on Preliminary Assessment - Turnagain Nickel Project
Wells, P. (2010-04-07): Technical Report on the Turnagain Project
Riles, A., Molavi, M. (2011-12-02): Preliminary Economic Assessment – Turnagain Project
Nixon, G.T., Milidragovic, D. and Scoates, J.S., Convergent margin Ni-Cu-PGE-Cr ore systems: temporal and magmatic evolution, Targeted Geoscience Initiative 5, Grant Program Interim Reports 2018-2019
Falconbridge File
Gigametals Corporation (2020-11-18): N.I. 43-101 Technical Report & Preliminary Economic Assessment for the Turnagain Project, British Columbia, Canada
Gigametals Corporation (2021-02-03): N.I. 43-101 Technical Report & Preliminary Economic Assessment for the Turnagain Project - Amended

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