- SMDI #
- 0302
- Current Showing Name
- Otonadah Lake Cu Showing and exploration shaft
- Historical Showing Names
- Otonadah Lake Cu Showing and exploration shaft
- Company Name
- Project Name
- UTM Easting (NAD83 Z13)
- 679691.5600
- UTM Northing (NAD83 Z13)
- 6085527.3200
- NTS Sheet
- 063L16
- TRM (Township-Range-Meridian)
- 68-02-2
- Primary Commodities
- Copper
- Associated Commodities
- Gold, Iron
- Discovery Type
- Trench
- Status
- Deposit: Advanced Exploration
- Geological Details
- The Otonadah Copper Showing lies along a low drift-covered ridge 396.2 m (1300 ft) south of Otonadah Lake - a small lake located about 800 m (0.50 mile) west of Tyrrell Lake.
The showing is hosted by easterly trending, north dipping, Nokomis Group (Amisk equivalent) Kesseynew type gneisses. The mineralization occurs within intercalated hornblende±pyroxene-garnet gneisses and amphibolites. The mineralization occurs at the top of the Nokomis Group gneisses within 5 to 10 m (16.4 to 32.8 ft) of the contact with the overlying Sherridon Group quartz-feldspar-biotite gneisses. The rocks hosting the deposit exhibit amphibolite facies metamorphism.
The showing consists of a thick gossan overlying sulphide replacement bodies in garnet-biotite gneiss of the Kisseynew Group about 450 ft (137.2 m) north of a large granodioritic intrusion. Five long trenches expose a 70 to 150 foot (21.3 to 45.7 m) width of jointed and schistose gneiss that hosts pyrrhotite, pyrite and minor disseminated magnetite and chalcopyrite mineralization.
The sulphide bodies are located about 400 feet (121.9 m) north of the contact between the Kisseynew gneisses and a large granodioritic intrusion. Wright examined the showing for the Geological Survey of Canada and reported that the chalcopyrite was not abundant enough across sections of 6 ft (1.8 m) or more to make an ore of copper, although certain narrow bodies of pyrrhotite were estimated to contain enough chalcopyrite to return assays of up to 4% Cu.
DRILLHOLE INTERSECTION WIDTH PPM PPM PPM PPB INTERSECTION
NUMBER (M) (M) CU ZN NI AU
_____________________________________________________________________________
WILD-2 19.80 - 20.20 0.40 336 1860 328 <10 py-po:meta-rhyolite
29.24 - 30.14 0.90 122 1400 144 <10 60% po,5% py,<1% sf
36.45 - 36.85 0.40 384 2520 410 <10 60% po,5% py,<1% cp
WILD-3 18.25 - 20.00 1.75 1500 4000 582 <10 50-60% po-py+sf,cp
20.00 - 21.00 1.00 1080 5680 672 12 " " " " " "
21.00 - 22.30 1.30 672 3000 622 12 " " " " " "
22.30 - 23.50 1.20 564 3000 426 50 " " " " " "
23.50 - 25.00 1.50 754 5780 500 10 " " " " " "
25.00 - 26.00 1.00 630 2000 384 <10 " " " " " "
27.00 - 28.00 1.00 600 5140 356 26 " " " " " "
28.00 - 29.00 1.00 806 5420 600 20 " " " " " "
29.00 - 30.00 1.00 1200 5260 574 10 " " " " " "
30.00 - 31.00 1.00 804 4600 608 <10 " " " " " "
31.00 - 31.90 0.90 638 6000 452 <10 " " " " " "
31.90 - 33.10 1.20 728 4500 408 <10 " " " " " "
The sulphide body is located 450 ft (137.2 m) north of the contact between the host rocks and a west-northwest-trending band of biotite granodiorite. The outcrops, around the showing,were mapped by A. Byers and C. Dahlstrom as unit 9b or garnet-biotite gneiss which were interpreted as metamorphosed sandstones, greywackes, and thinly interbedded sandstones and quartzose shales.
During later mapping, K. Ashton determined the host rocks to be meta-greywackes. The showing trenches expose amphibolite and the above-described gneiss. The pyroxene has been completely altered to amphibolite which is partly crushed and replaced and cut by quartz. The amphibolite and quartz are, in turn, cut and replaced by sulphides (mainly pyrite). Byers and Dahlstrom mapped the amphibolites and associated hornblende, garnet-hornblende, garnet-hornblende-pyroxene gneisses and garnetiferous amphibolite as unit 8a. K. Ashton interprets unit 8a rocks to be metamorphosed intermediate to mafic volcanic and volcaniclastic rocks.
Polished sections indicate that the massive pyrite present is often replaced by pyrrhotite and, locally, the pyrrhotite is replaced by minor chalcopyrite. Certain massive pyrrhotite bodies assay up to 4% chalcopyrite.
- Geological Domain
- Flin Flon
- Host Rocks
- Host Minerals
- Pyrite, Pyrrhotite
- Indicators
- Exploration History
- 8/11/1988 The showing was originally staked as the BIRCH claims by Mr. John Beda and associates. In 1929, Nipiwan Mining Company, under the direction of Mr. Harry Moody, completed 3 large trenches and numerous small trenches to expose the mineralization. The trenches failed to penetrate the gossan. A 28 m (91.86 ft) vertical exploration shaft was sunk 115 ft north of the most easterly trench. The claims were allowed to lapse.
In 1954, W. Boehme staked the showing as the GOOD Claims Nos. 1 to 4. Two trenches were completed on the north shore of Otonadah Lake (AF 63L16-0021). A. R. Byers and C.D.A. Dahlstrom mapped the area for the Saskatchewan Geological Survey. They located a small showing that outcrops on a low drift-covered ridge 1300 ft (396.2 m) south of Otonadah Lake. This showing was investigated by L.S. Beck in 1959 for the Saskatchewan Geological Survey.
By 1961, Selco Explorations had staked Otonadah to Little Otonadah Lakes as the RICH claims Nos. 1 to 26. In 1961, SELCO drill tested an anomaly on RICH claim No. 6 (under Otonadah Lake). Drill hole no. 2 intersected massive pyrite-pyrrhotite and minor specks of chalcopyrite and magnetite (AF 63L16-0032).
In 1966, Hudson Bay Exploration and Development staked the area as CBS 755 and established a large grid between Otonadah and Tyrrell Lakes. They completed ground HLEM and turam surveys over the grid to ground locate airborne anomalies (AF 63L16-0028). Hudson Bay then completed 3 anomaly holes well south of the showing (AF 63L16-0026). Eventually, CBS 755 was allowed to lapse.
On 20 June 1985, D. Forster staked the showing area as CBS 3735. In 1986, Homestake Mineral Development Company completed a reconnaissance program of geological mapping, lithogeochemistry and ground VLF-EM and humus surveys on the Otonadah grid (AF 63L16-0109). The trenches were chip sampled as part of this gold exploration program. One chip sample (TY-01-4-05604) taken from the west trench returned 580 ppb Au.
On 1 November 1987, CBS 3735 was allowed to lapse.
On 24 July 1989, Cominco staked the showing as S-99644. In 1992, they completed drill hole WILD-3 in the immediate vicinity of the showing and WILD-2 to the northwest of the showing to test two HLEM conductors (AF 63L16-0151). The better intersections are reported above.
In 1992, BHP-Utah Mines Ltd. re-calculated the deposit reserves (AF 63L16-0152).
- Production History
- Reserves and/or Resources
- 1992-01-01
100,000 tonnes grading 3.4% Cu, 1.5% Zn.
Summary:
Historic reserve (unspecified) of 100,000.00 tonne
- Copper @ 3.4 %
- Zinc @ 1.5 %