Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI000000000189

Record: MDI000000000189

General

Commodities

Primary Commodities: Gold

Location

Township or Area: Tarp Lake Area

Latitude: 51° 33' 22.54"    Longitude: -90° 3' 46.48"

UTM Zone: 15    Easting: 703600   Northing: 5715775    UTM Datum: NAD83

Resident Geologist District: Thunder Bay North

NTS Grid: 52O09SE

Point Location Description: Location from assessment file map in AFRO# 2.32421.

Location Method: Data Compilation

Exploration History

1945: property was staked by Norpick Gold Mines Ltd. 1946: Norpick Gold Mines discovered the showing. 1979: Dora Explorations carried out linecutting, a ground VLF-EM survey, and drilled 34 DDH totalling 2957 m, with 3 holes on the Carbonate Zone. 1989: Hughes-Lang Corp. staked the property. 1990: Hughes-Lang completed an airborne mag/VLF-EM survey. 1991: Homestake optioned the property and carried out linecutting, ground geophysics, geological mapping, trenching, detailed channel sampling, and drilled 2 DDH, totaling 433.82 m. 1992: Homestake / 2002-03: MetalCORP Ltd. staked the property and carried out prospecting, trenching, mapping,, and channel sampling.

Assessment Work on File

Geology

Province: Superior

Subprovince: Uchi

Terrane: North Caribou

Domain: Uchi

Belt: Pickle Lake

Geological Age: Mesoarchean  

Geology Comments

Dec 18, 2006 (Mark Puumala) - The Tarp Lake area gold prospects and occurrences are located in the northern portion of the Pickle Lake Greenstone Belt. These occurrences are found within a mafic metavolcanic rock dominated supracrustal sequence identified by Young (2003) as being part of the > 2860 Ma Pickle Crow Assemblage. According to Young (2003), the Pickle Crow assemblage is dominated by massive and pillowed mafic metavolcanic flows with subordinate (likely synvolcanic) gabbroic sills. MacTavish (2006) describes the mafic metavolcanic flows as being commonly well-foliated to schistose, amphibolitized, and often finely-amygdaloidal. In addition, MacTavish (2006) indicates that the mafic metavolcanics include units of pillow and hyaloclastite breccia. The gabbroic sills are described by MacTavish (2006) as fine- to coarse-grained gabbro, melagabro and ferrogabbro sills up to 200 m thick. The mafic metavolcanics are intercalated with thin, laterally continuous banded iron formation and small, discontinuous lenses of intermediate to felsic metavolcanics. A significant 90 to 125 m thick northeast-trending unit of felsic to intermediate tuff breccia to pyroclastic breccia has been reported in this area by MacTavish. Relatively thin units (up to 70 m thick) of clastic metasedimentary rocks have also been reported by MacTavish (2006). All lithologies are intruded by semi-concordant feldspar porphyry dikes. These dikes are reported by MacTavish (2006) to vary widely in thickness and lateral continuity. MacTavish (2006) also indicates that all lithologies are crosscut by late biotite lamprophyre dikes that are up to 5 m in thickness. One of these dikes is reported to contain ultramafic and country rock xenoliths, red garnets and greenish diopside. Stratigraphy in the Tarp Lake area generally faces toward the northwest, except where asymmetric folding (mainly further to the southeast in the Pickle Crow mine area) has caused reversals in the younging direction (Young 2003). The dominant geological structure in the Tarp Lake area is the Tarp Lake Shear Zone. This structure strikes northeast and forms a wide, diffuse and anastamosing deformation zone that is poorly exposed and characterized (MacTavish 2006). The mafic metavolcanic rocks affected by this shear zone are characterized by moderate to intense carbonatization, sericitization and local silicification (MacTavish 2006). This alteration zone hosts the numerous gold occurrences throughout the area. Many of the more significant gold prospects appear to be located where the Tarp Lake Shear Zone is intersected by splays and/or later fault/shear zones, or relatively competent lithological units such as porphyry intrusions, gabbro and iron formation. The cross-cutting deformation zones are most commonly reported to strike approximately northwest, east-west and north-northeast. Similar complex faulting/shearing patterns have been noted nearby by MacQueen (1987) in the vicinity of the Pickle Crow gold mine, and by McAuley and Winter (1990) in the vicinity of a number of gold occurrences in the July Falls area.

Lithology

Mineralization

Mineralization Comments

Dec 18, 2006 (Mark Puumala) - The Carbonate Zone is described by Potts (1992) as a broad zone of intense ankerite alteration with gradational contacts with the surrounding pillowed mafic volcanic flows. The alteration zone is reported to strike between 080 and 090. This zone is characterized by evidence of significant deformation, including fracturing, brecciation, weak silicification and elevated sulphide content. Mineralization is reported by Potts (1992) to consist of fine disseminated and stringer pyrite and fine arsenopyrite fracture-fillings, with higher gold values associated with arsenopyrite. The sulphide concentrations locally approach 10 to 15%. Mineralization is reported by Potts (1992) to occur in two zones oriented approximately 270-275/50-80 and 340-350/70-80. The carbonate alteration zone is reported by Potts (1992) to be cut off at the west end of the outcrop exposure by a northeast-striking fault. To the east, the alteration zone is reported by Potts (1992) to extend eastward a minimum of 350 m to Dora Exploration diamond drill hole D-24 (AFRI# 52O09SE0129). Similar alteration and mineralization was reported at depth in an approximately 35 m wide intersection in Metalcorp diamond drill hole PM04-06 (MacTavish 2004). A number of anomalous gold assay results have been reported for this prospect from channel sampling and diamond drilling. Channel sampling results reported by Homestake (Potts 1992) included 2.25 g/t over 4.8 m and 1.48 g/t over 4.8 m. An assay of 1.127 g/t over 12 m has been reported by MacTavish (2004) from Metalcorp ddh PM04-06. Potts (1992) reports the presence of anomalous gold concentrations (0.632 g/t over 1.03 m) in interflow sediments that occur within a sequence logged as foliated basalt in Homestake Canada ddh PP91-01. A second anomalous intersection (0.722 g/t over 0.3 m) was reported from material logged as containing a quartz carbonate vein with 5 to 8% pyrite. This hole was drilled to explore for an eastern extension of the Carbonate Zone prospect. However, it is unclear if the mineralization noted at this location is related.

Jan 19, 2022 (Therese Pettigrew) - In 1979, Dora Explorations drilled 3 holes to test the Carbonate Zone with anomalous to low-grade results of up to 1.03 gpt Au over 1.37 m (0.030pt Au over 4.5 ft). Homestake's 1991 program exposed a 60 m wide zone of intense ankerite alteration at the Carbonate Zone grading up to 5.046 gpt Au / 0.90 m with one sequence of channel samples, located near the northeastern edge of the exposed zone, grading 1.347 gpt Au / 15.30 m, including 4.887 gpt Au / 1.0 m (Assessment report 20000001524).

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