Mineral Deposit Inventory for Ontario

Ontario Geological Survey
Permanent Link to this Record: MDI000000002691

Deposit: MDI000000002691

General

Commodities

Primary Commodities: Gold, Copper

Location

Township or Area: North Caribou Lake Area

Latitude: 52° 50' 50.38"    Longitude: -90° 33' 19.53"

UTM Zone: 15    Easting: 664621   Northing: 5858087    UTM Datum: NAD83

Resident Geologist District: Thunder Bay North

NTS Grid: 53B15SE

Point Location Description: DDH RGR-19-05 from Assessment report 20000019458

Location Method: Data Compilation

Assessment Work on File

Geology

Province: Superior

Subprovince: Berens River

Belt: North Caribou

Geological Age: Archean  

Lithology

Lithology Comments

DDH RGR-19-05 intersected a predominantly basaltic sequence cut by two feldspar porphyry (FP) dykes plus two sericitized equivalents (1.35 to 7.65 m wide), five quartz-feldspar porphyry (QFP) dykes/sills, 2.2 m to 5.0 m wide, and four quartz-eye “rhyolite” dykes/sills, 2.8 m to 12.0 m wide (Assessment report 20000019458).

Mineralization

Mineralization Comments

Oct 29, 2021 (Therese Pettigrew) - DDH RGR-19-005 returned up to 8.64 g/t Au over 4.5 m from a quartz-pyrrhotite vein and 4.30 g/t Au and 1.33% Cu over 1.45 m from stringer chalcopyrite. DDH RGR-19-008 returned up to 46.40 g/t Au and 1.68% Cu over 0.2 m from a pyrrhotite-rich metasediment and felsic tuff (Paju et al., 2020). A major gold-bearing quartz vein system was intersected in DDH RGR-09-05 from 288.85 to 294.35 m and returned a weighted average gold value of 8.64 g/t Au over 4.75 m, including 31.30 g/t Au over 0.8 m. This vein system is a ~50:50 mix of ~8 fairly distinct quartz veins, 20-80 cm wide, and highly biotitized and foliated wallrock intervals of approximately equal size. Wallrock intervals appear to be mainly basalt with lesser feldspar porphyry; many parts are largely or completely replaced by biotite and laced with foliation-parallel micro-veinlets of calcite. Many intervals are a complex mix of smaller veins and altered wallrock overprinted with variable pyrrhotite (Po). Most of the Quartz-Po veins are ~mottled white and light grey, with nil to 30% Po over 30cm as irregular networks/patches up to 10-15 cm wide of 30-40% massive Po, some weakly aligned. Some quartz veins are clearly sheeted with up to 5-6 wallrock slivers <1 cm wide, highly biotitized and lined with thin Po seams. One later generation of white quartz veins 5-10 cm wide cross-cuts the earlier, more complex veins. In addition to the significant Po veins/patches/seams throughout the quartz veins and altered wallrock, 10 specks of visible gold, ~1mm, were observed on core surface with additional ones on the cut surface after being sawn for sampling. The gold is often found near vein margins in the quartz, as well as in the late clean white quartz veins, and some near the Po seams. The gold-bearing vein is flanked above by a narrow feldspar porphyry dyke with a few minor quartz veins and sporadic pyrrhotite, and below by basalt that is strongly to moderately biotitized, with spotty pyrrhotite for ~3 to 3.5 m, decreasing to weak farther downhole (Assessment report 20000019458).

Mineral Deposit Details

References

Mono - Report of Activities 2019, Resident Geologist Program, Thunder Bay North Regional Resident Geologist Report: Thunder Bay North District

Publication Number: OFR6364 Scale:     Date: 2020

Author: Cundari R.M., Paju G.F., Dorado-Troughton M., Daniels C.M., Fudge S.P., Pettigrew T.K., Dorland G.

Publisher Name: Ontario Geological Survey

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Ministry Contact Information

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