Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI52C11NE00047

Record: MDI52C11NE00047

General

Commodities

Primary Commodities: Copper, Platinum, Palladium, Nickel

Location

Township or Area: Halkirk

Latitude: 48° 42' 53.48"    Longitude: -93° 2' 1.62"

UTM Zone: 15    Easting: 497515.003   Northing: 5395759.003    UTM Datum: NAD83

Resident Geologist District: Kenora

NTS Grid: 52C11NE

Point Location Description: Taken from geology map with occurrences AFRO 2.32111

Location Method: Conversion from MDI

Access Description: The property is access from Highway 11 east of Fort Frances - there is a series of logging roads and railway beds provide access to the internal parts of the Grassy Portage intrusive rocks.

Exploration History

There is a long history of base metals exploration within the North Rock area, with the earliest recorded work occurring in 1918, with possible, unrecorded work as early as 1902. Research suggests that there has been little exploration for the platinum group elements (PGE's) and only minor interest in Au. Most of the exploration activity occurred between 1958 and 1978 and was sporadic before or since.2001, 2003 to 2006 as presented in MetalCORP, Kenora assessment file 52C11NE BBB-8 AFRO 2.37249 Two prospecting programs were completed during 2003 and 2004. The property was optioned to MetalCORP Ltd (MTC) during October 2004. During 2005 and 2006 MTC completed an AeroTEM IT helicopter-borne survey, Phase 1 and II diamond drill programs, linecutting, detailed prospecting, and geological mapping.

Assessment Work on File

Geology Comments

Mar 03, 2011 (C Ravnaas) - The North Rock Property is primarily underlain by the differentiated Grassy Portage Intrusion (GPI) with lesser amounts of the Grassy Portage ultramafic pyroclastic sequence (GUP); clastic metasedimentary rocks of the Couchiching Metasediments; granitoid rocks of the Bear Passage and Blind Bay plutons; sections of2 formational, composite, chemical/clastic metasedimtmtary sequences; two narrow mafic metavolcanic units; and a few, possibly subvolcanic gabbro sills. All observed rocks-types comprise the southern limb of a large-scale open, antiformal fold cored by the Rice Bay Dome located approximately 1.50 km north of the property (Figure 3). Most rock-types have been regionally metamorphosed to lower amphibolite-grade. The southwestern two-thirds of the Grassy Portage Intrusion underlies the core of the property (~75%). This large, sill-like, mafic complex intrudes all observed supracrustal rock-types, and is composed ofa well-differentiated, locally layered, cumulate sequence of medium- to coarse-grained, melagabbro, gabbro and leucogabbro; coarsely plagiophyric to glomero-plagiophyric gabbro to leucogabbro; localized intervals ofmedium- to coarse-grained anOlthosite; and a discontinuous, noncumulate, ophitic-textured, melagabbroic border phase that is present along both the upper and lower contacts ofthe complex. The intrusion is structurally overturned and stratigraphically south-facing. Cha1copyrite-dominated mineralization concentrates along both upper and lower contacts with the greatest sulphide abundances observed near the basal or northern contact. Reference MetalCORP, Kenora assessment file 52C11NE BBB-8 AFRO 2.37249

Lithology Comments

Mar 03, 2011 (C Ravnaas) - The mineralized corridor is fairly constant from the west extremity of Beaver Pond Zone to the east end of East Zone covering up to l.5km along this contact. Traversing from the south northward to the contact with the GPI is very poorly mineralized medium grained gabbro, which gabbro becomes melanocratic with an increase of sulphides (po-cpy mainly) when getting closer to the contact at an average distance of20 meters up to 5 meters to the contact where a coarse grained leucocratic pegmatitic horizon develop with a width of I to 5 meters before hitting the contact. The melanocratic gabbro contains 1races increasing to 8% of disseminated sulphides with local spots that can reach up to 15% mainly in pyrrhotite and chalcopyrite. The contact leuco gabbro contains less sulphide, with an average of I to 3% disseminated or blebby sulphides, but is regularly higher grade than the melanocratic gabbro. The sulphides are normally distributed as disseminated, blebs of wisps in the matrix. On the north side of the contact, considered to be the hanging wall as well as the host rock, a thin band of ultramafic rocks separate the gabbro from the meta-volcanic rocks to the north. This band is irregular, and sometimes disappears at the contact where it generally varies from I to 5 meters in thickness and consists in some basal mafic to ultramafic intrusive rock such as a fine grained mela-gabbro or fine to medium grained pyroxenite. Mineralization is found irregularly in these rocks as pods or patches mostly found along the local fracture paths, and consist of pyrrhotite and chalcopyrite. Some relatively high values of Platinum Group Minerals have been found preferentially in this horizon. Finally, passed this horizon is an environment of pillowed mafic meta volcanic rocks that occasionally contain remnant patches of mineralization also associated with two major fracture patterns running roughly at 340 and 020 azimuths. Reference MetalCORP, Kenora assessment file 52C11NE BBB-3 AFRO 2.32111

Mineralization

Mineralization Comments

Mar 03, 2011 (C Ravnaas) - There are a series of showing located new the north contact of the Grassy Portage mafic Intrusion. This previously trenched occurrence was rediscovered by Mike Hupchuk in 1963 and is located 80 m east of Highway 11 and 130 m northeast of the Highway11 CNR overpass, near the lower contact of the Grassy Portage Intrusion. Samples taken from the large trench by the Harris (1974) were similar to the 'black ore' of the Beaver Pond Deposit and contained 0.20% Cu and 0.13% Ni over 9.0ft (27.4 m chip sample). The OGS sampled the occurrence in August 2005 and described it as variably altered gabbro and speckled gabbro containing between 3 and 23% pyrrhotite and chalcopyrite and 8612 ppm Cu, 8314ppm Ni, and 6.0 ppm Ag. MTC 2005 samples contained up to 7930 ppm Cu, 1700 ppm Ni, 1.0 ppm Ag, and 0.172 ppm Pd. The Highway 3 Occurrence and new occurrence is located 25 m west of Highway 11, and 130 m west-northwest of the Belacoma Occurrence, at the basal contact of the Grassy Portage Intrusion. Mineralization consists of 1 to 2% disseminated chalcopyrite and pyrrhotite and within medium- to very coarse-grained, moderately varitextured gabbro that contained up to 6260 ppm Cu, 1130ppm Ni, 2.7ppm Ag, 0.220ppmAu, 0.371 ppm Pd, and 0.448 ppm Pt. Reference MetalCORP, Kenora assessment file 52C11NE BBB-3 AFRO 2.32111

Mineral Record Details

References

File - Mineral Deposit Files

Publication Number: Date:

Author:

Publisher Name:

Location:

Book - RAINY LAKE AREA

Publication Number: N/A Date:

Author: Harris, F.R.

Publisher Name:

Location: GR 115

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Ministry Contact Information

For detailed information regarding this mineral record please contact the Kenora Resident Geologist District Office