Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI52P12SW00013

Record: MDI52P12SW00013

General

Commodities

Primary Commodities: Copper, Zinc

Secondary Commodities: Gold, Silver

Location

Township or Area: McCullagh

Latitude: 51° 30' 40.06"    Longitude: -89° 58' 12.78"

UTM Zone: 16    Easting: 293900   Northing: 5710850    UTM Datum: NAD83

Resident Geologist District: Thunder Bay North

NTS Grid: 52P12SW

Point Location Description: Assessment file map and ddh database.

Location Method: Conversion from MDI

Exploration History

1930s: Prospecting and stripping work by unknown operator. 1985-1989: An exploration program consisting of airborne geophysics, ground geophysics, and diamond drilling was carried out on a claim group in the vicinity of this prospect by Kerr Addison Mines and Minnova.

Assessment Work on File

Geology

Province: Superior

Subprovince: Uchi

Terrane: North Caribou

Domain: Uchi

Belt: Pickle Lake

Geological Age: Neoarchean  

Geology Comments

Nov 10, 2006 (Mark Puumala) - The McCullaugh Creek zinc prospect is located in the northeastern portion of the Pickle Lake Greenstone Belt within a northeast-striking sequence of supracrustal rocks defined by Stott (1996) as the Woman Assemblage. This assemblage has subsequently been re-named the Kaminiskag Assemblage (Young 2003). Rocks of the Kaminiskag Assemblage are bounded to the southeast by granitic rocks of the Second Loon Pluton and to the northwest by metavolcanic rocks of the Confederation Assemblage (Young 2003). The area surrounding this prospect has limited outcrop exposure. As a result, much of the information regarding lithologies has been collected from diamond drill logs (Stott 1996). Rocks of the Kaminiskag assemblage are dominated by mafic metavolcanic flows, with thinner layers of felsic to intermediate metavolcanic ash flows. Minor amounts of banded iron formation have been reported in the mafic metavolcanics, and fine-grained clastic metasediments have been documented in diamond drill core sections inter-bedded within the felsic to intermediate volcanics. The mafic metavolcanics are generally strongly-foliated massive amphibolites, although minor amounts of ultramafic material have also been reported (Stott 1996). The main felsic to intermediate volcanic unit is a quartz-phyric dacite tuff that can be traced over a strike length of 8 km. This unit locally contains thin, massive sulphide lenses that are dominated by pyrrhotite and are overlain by chert (Stott 1996). This is the type of mineralization that is found at the McCullagh Creek prospect. Stott (1996) indicates that the results of a U-Pb zircon age determination from this unit provided an age of approximately 2836 Ma. Rocks in the area of the McCullagh Creek prospect generally exhibit north-dipping schistosity and northwest-plunging mineral lineations that conform to the igneous fabrics of the nearby Second Loon pluton. This pluton is interpreted by Stott (1996) to have imposed a contact strain aureole and amphibolite facies metamorphism within the relatively thin greenstone belt tail that is present at the northeast end of the Pickle Lake Greenstone Belt. Diamond drill hole logs from this prospect indicate the presence of a northeast-striking fault that parallels McCullagh Creek. The fault generally cross-cuts mafic metavolcanics, and is located immediately northwest of the base metal-mneralized quartz-phyric ash tuff horizons. The fault zone is several metres wide and borehole logs indicate that it is characterized by shearing, graphitic and chloritic bands, brecciation, disseminated sulphides and quartz-carbonate veining. Drill hole logs also commonly indicate the presence of small-scale folds.

Lithology

Mineralization

Mineralization Comments

Nov 10, 2006 (Mark Puumala) - The first report of the potential for economic mineralization in the McCullagh Creek area was provided by Hurst (1931), who described pyrite, pyrrhotite and chalcopyrite mineralization in trenches on a property referred to as the Maloney Claims. This appears to be the only surface exposure of the mineralized horizon that hosts the McCullagh Creek prospect. Diamond drill logs indicate a relatively complex stratigraphy in this area, consisting of interlayered mafic metavolcanics, chert, iron formation and felsic metavolcanics. The rocks to the northwest are dominated by mafic metavolcanics, with increasing quantities of felsic metavolcanics toward the southeast. A horizon consisting of chert and iron formation appears to occur at a transition zone between predominantly mafic material and a sequence dominated by felsic tuffs. The base metal-mineralized horizons at this location are hosted within stratigraphic units identified as quartz-phyric ash tuff on Minnova diamond drill hole logs (AFRI52P12SW0070). Significant zinc, copper and silver mineralization has been identified in 10 diamond drill holes (KAF-86-06, KAF-87-16 and -17, KAF-88-27, KAF-89-28 to -32 and -35) covering a strike length of approximately 850 m. Anomalous gold values have also been reported in some drill core sections. The mineralization zones are relatively narrow (i.e., generally less than 1.2 m wide), and include pods of massive sulphide, disseminated sulphide and narrow (a few cm wide) massive sulphide veins. Mineralization is reported to consist of variable quantities of pyrite (up to 85%), sphalerite (up to 20%), chalcopyrite (up to 5%) and galena (up to 5%). Separate pods of massive pyrrhotite have also been reported in the diamond drill hole sections. However, these horizons contain low base metal values and generally appear to be associated with chert/iron formation horizons within the mafic metavolcanics. Some of the most notable assays from this prospect include the following. 6.31% Zn, 1.82% Cu and 84 ppm Ag over 0.3 feet in DDH KAF-86-06; 5.05% Zn, 0.9% Cu and 61 ppm Ag over 1.1 feet in DDH KAF-88-27; 2228 ppb Au over 2 feet in DDH KAF-87-27; 2.53% Zn, 0.35% Cu and 35.1 ppm Ag over 2 feet in DDH KAF-89-30.

Mineral Record Details

References

Map - Cat Lake-Pickle Lake, geological compilation series, Kenora and Thunder Bay districts

Publication Number: M2218 Scale: 1:253,440    Date: 1976

Author: Sage R.P., Breaks F.W., Troup W.R.

Publisher Name: Ontario Division of Mines

Location:

Map - Geological series, Precambrian geology, Pickle Lake area, eastern part

Publication Number: P3057 Scale: 1:50,000    Date: 1989

Author: Stott G.M., Brown G.H., Coleman V.J., Green G.M., Reilly B.A.

Publisher Name: Ontario Geological Survey

Location:

Part - The ceramic industry of Ontario

Publication Number: ARV39-04 Page: 25-26  Date: 1997

Author: Montgomery R.J.

Publisher Name: Ontario Dept. of Mines

Location:

Mono - Copper, nickel, lead and zinc deposits of Ontario

Publication Number: MDC012 Page: 188  Date: 1969

Author: Shklanka R.

Publisher Name: Ontario Dept. of Mines

Location:

Mono - The Geology and Tectonic History of the Central Uchi Subprovince

Publication Number: OFR5952 Date: 1996

Author: Stott G.M.

Publisher Name: Ontario Geological Survey

Location:

Book - New Structural, Geochronological, and Geochemical Constraints on the Tectonic Assembly of the Archean Pickle Lake Greenstone Belt, Uchi Subprovince, Western Superior Province

Publication Number: Date:

Author: Young, M.D. 2003.

Publisher Name: unpublished thesis, Queen's University

Location: Thunder Bay RGP

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For detailed information regarding this mineral record please contact the Thunder Bay North Resident Geologist District Office