Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI52C11NE00029

Record: MDI52C11NE00029

General

Commodities

Primary Commodities: Copper, Platinum, Palladium, Nickel, Gold

Secondary Commodities: Molybdenum, Diamond

Location

Township or Area: Halkirk

Latitude: 48° 42' 1.32"    Longitude: -93° 4' 3.31"

UTM Zone: 15    Easting: 495027   Northing: 5394150    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 accessed from Highway 11 east of Fort Frances - there is a series of logging roads which 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. 1958-70: Noranda discovered the deposit in 1958. Between 1958 and 1970, Noranda flew an airborne magnetometer and EM survey and completed trenching, linecutting, geological mapping, ground magnetometer, JEM and VLF-EM surveys, drilled 16 DDH totalling 1845 m in 1959 and 1960 and 31 DDH totalling 3563 m in 1966 and 1967. 1968: Seemar Mines Ltd. optioned the property from Noranda. 1969-70: Seemar drilled 16 DDH totalling 2380.8 m. 1970: the claims were brought to lease. 1971: Seemar entered into an agreement with North Rock Explorations Ltd. in order to finance continued exploration. 1971-72: North Rock drilled 17 DDH (unknown length). 1972-73: North Rock had a limited underground development program consisting of a 200 ft shaft and 213 m of drilling on the 175 ft level. 1973: Work ceased and the property was turned over to Nor-Norock Mining Company Ltd., who commissioned an appraisal of the property. 1974: No-Norock drilled 1 DDH totalling 76.5 m. 1990: No-Norock commissioned J.E. Steers and Associates Inc. to prepare an independent report on the property. 1999: leased claims were allowed to lapse. 2001: claims were staked by J.E. Bond II, A. Eveleigh and J.G. Clark and optioned to Northern Crown Mines Ltd. who conducted a prospecting program. Beaver Pond Zone rock dump was sampled by Inco Ltd., Greenshield Resources and North American Palladium. 2004: MetalCorp Ltd. optioned the property. 2005: Metalcorp drilled 14 DDH totalling 3906 m. 2006: MetalCorp completed an airborne magnetic/EM geophysical survey, geological mapping and sampling, and drilled 21 DDH totalling approx. 4000 m. 2007: MetalCorp drilled 25 DDH totalling approx. 8000 m. 2008: MetalCorp discovered micro-diamonds in February. Kennecott Canada Exploration Inc. optioned the property in December. 2009: Kennecott returned the property to MetalCorp in September.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wabigoon

Terrane: Western Wabigoon

Belt: Fort Frances-Mine Centre

Geological Age: Precambrian  

Geology Comments

Mar 02, 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

Lithology Comments

Mar 02, 2011 (C Ravnaas) - The Beaver Pond Zone is located -150 m southeast of Grassy Portage Bay of Rainy Lake, approximately 2850 m west of Highway 11. This Cu-rich zone is poorly exposed at surface, but below surface consists of3, discontinuous, en echelon masses of disseminated to net textured chalcopyrite, with subordinate pyrrhotite and localized disseminated molybdenite, within variably altered leucogabbro (grey ore), gabbro, coarsely plagiophyric to glomeroplagiophyric gabbro, and melagabbro (black ore) near the basal contact ofthe Grassy Portage Intrusion. The grey ores often contain >3% Cu and consist of bleached anorthosite and leucogabbro rich in chalcopyrite. The alteration consists of clinozoisite (epidote), minor sericite and scapolite, and associated pale green apatite and course, equant, ilmenite rimmed or replaced by biotite. The black ores usually contain less chalcopyrite «1% Cu) within equigranular to porphyritic, variably chloritized gabbro and melagabbro. Molybdenite occurs as intergrowths with chalcopyrite and pyrrhotite or as discrete grains within grey patches of hydrothermally altered gabbro. 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

Jun 30, 2015 (Therese Pettigrew) - The North Rock property is underlain by the 20 km long Grassy Portage layered mafic intrusion and hosts four known zones of magmatic copper-nickel sulphide mineralization: the Beaver Pond (main target), the Main South, the East and the West zones, all of which occur at or near the base of the intrusion, along its western contact.

Mineralization

Mineralization Comments

Mar 02, 2011 (C Ravnaas) - Grades within the zone vary from <1% to >3% Cu over variable widths over a strike length of~400 m. Underground driiting (53 m level) on the Beaver Pond Zone during 1971 and 1972 exposed 2 zones that averaged in excess of3.00% Cu. Tonnage and grade calculations, completed by Bergman (1973), include 1,020,458 tons grading 1.17% Cu over a 400 m strike length and 265,230 tons grading 2.08% Cu over a 300 m strike length. Both tonnage estimates are good to a depth of only 91 m. Three surface grab samples taken from the poorly exposed zone in 2005 contained up to 0.576% Cu, 0.138% Ni, 0.435 ppm Pd, and 0.265 ppm Pt. A single grab sample taken from a surface stockpile from a 1973 underground bulk sample that was never processed, contained 6.78% Cu, 0.106% Ni, 381 ppm Co, 7.3 ppmAg, 0.120 gpt Au, and 5.15ppm Pt. Reference MetalCORP, Kenora assessment file 52C11NE BBB-3 AFRO 2.32111

Jun 30, 2015 (Therese Pettigrew) - The “zone” consists of en echelon lenses, “A”, “B”, and “C”, of chalcopyrite-pyrrhotite mineralization which extends discontinuously for at least 300 m in an east-west direction. Both high grade “grey” ores and lower grade “black” ores are present. The grey ores are rich in chalcopyrite (3% Cu) and consists of bleached anorthosite which is characterized by clinozoisite alteration with minor sericite and scapolite. Pale green apatite and equant cm-wide ilmenite grains are common associates. Biottie halos commonly replace ilmenite grains and molybdenite is present locally. The black ores contain less chalcopyrite (less than 1% Cu, 0.1% Ni) and consist of equigranular to porphyritic gabbro with sulphides as interstitial grains and fracture fillings. Molybdenite occurs locally with the chalcopyrite and pyrrhotite or as discrete grains in grey alteration patches within the gabbro (Poulsen, 1984). MetalCorp’s Hole 4 intersected 1.5% Cu over 13.7 m and also intersected a hangingwall Platinum Group Metal zone that can be traced for 500 m along strike and to a depth of 200 m. Assay values as high as 3.7 g/t Pt + 7.1 g/t Pd over 0.8 m were reported (www.metalcorp.ca/north-rock). MetalCorp’s Hole 20 returned assays of 1.2 gpt Pt, 0.1 gpt Pd, 0.1 gpt Au, 0.6% Cu, and 0.2% Ni over 3.7 m (151.9-155.6 m) (MetalCorp news releases March 6, 2006 and April 19, 2006). MetalCorp announced in February 2008 the discovery of micro-diamonds on the property in the Grassy Ultramafic Pyroclastic. MetalCorp took a 100kg sample and sent it for processing by Kennecott Canada Exploration Inc. A total of six diamonds were recovered with one sitting on the 0.212 mm sieve, three were on the 0.106 mm sieve and two were less than the 0.106 mm sieve size (MetalCorp news release Feb 5, 2008). The best Cu values have been intersected in the Beaver Pond area on the extensions of the know Noranda mineralization with values in excess of 3.0% Cu from holes NR05-001 to NR05-005, over 4.0% Cu from hole NR05-009 and just below 4.0% Cu in hole NR05-013. The widths generally vary from 0.5 to 4.0 m. A few intervals demonstrated considerable widths such as NR05-004 with 1.04% Cu over 23.6 m, NR05-005 with 0.55% Cu over 25.8 m and NR05-13 with 1.52% Cu over 9.4 m. Silver is fairly consistently high (up to 18.00 gpt in NR05-009) where Cu is anomalous. Two gold values were intersected in the footwall of the gabbro with 5.96 gpt over 0.6 m in hole NR05-001 and 3.0 gpt over 0.7 m in hole NR-05-005. Hole NR05-002 returned 1.74 and 6.63 gpt Pt over 2.8 and 0.4 m, a value of 2.28 gpt Pt over 3.46 m out of hole NR05-004, some 3.74 gpt Pt and 7.09 gpt Pd over 0.8 m from hole NR05- 005, 2.02 and 2.94 gpt Pd over 1.2 and 0.5 m from hole NR05-005, some 1.17 gpt Pt over 4.0 m out of NR05-007, and finally hole NR05-009 with 1.22 gpt Pt and 2.21 gpt Pd over 1.0 m (AFRI 20000003506).

Mineral Record Details

References

Map - Precambrian Geology and Mineral Occurrences, Mine Centre-Fort Frances Area

Publication Number: M2525 Scale: 1:50,000    Date: 2000

Author: Poulsen K.H.

Publisher Name: Ontario Geological Survey

Location:

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

Publication Number: MDC012 Page: 219  Date: 1969

Author: Shklanka R.

Publisher Name: Ontario Dept. of Mines

Location:

MonoMap - Geology of the Rainy Lake area, District of Rainy River

Publication Number: R115 Page: 61-71  Date: 1974

Author: Harris F.R.

Publisher Name: Ontario Division of Mines

Location:

Mono - The geological setting of mineralization in the Mine Centre-Fort Frances area, District of Rainy River

Publication Number: OFR5512 Page: 50-52  Date: 1984

Author: Poulsen K.H.

Publisher Name: Ontario Geological Survey

Location:

MonoMap - Archean Metallogeny of the Mine Centre-Fort Frances Area

Publication Number: R266 Date: 2000

Author: Poulsen K.H.

Publisher Name: Ontario Geological Survey

Location:

Map - Rice Bay, Rainy Lake, Rainy River District

Publication Number: M2278 Scale: 1:31,680    Date: 1974

Author: Harris F.R.

Publisher Name: Ontario Division of Mines

Location:

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