Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI42L04NE00027

Record: MDI42L04NE00027

General

Commodities

Primary Commodities: Silver, Gold

Secondary Commodities: Copper

Location

Township or Area: Oboshkegan

Latitude: 50° 9' 45.55"    Longitude: -87° 36' 20.52"

UTM Zone: 16    Easting: 456738   Northing: 5556891    UTM Datum: NAD83

Resident Geologist District: Thunder Bay North

NTS Grid: 42L04NE

Point Location Description: Stripped outcrop map in Assessment file 20000000550

Location Method: Conversion from MDI

Access Description: Access to the main occurrence on the property is via the Kinghorn Road, which intersects Highway 11 7.5 km east of Jellicoe, north for approximately 80 km to the Metcalfe Lake bush road (local name). The main showings are located a further 4 km southeast along the Metcalfe Lake road.

Exploration History

1976: OGS Staff member S. Amukun mapped the area and identified the occurrence. 1987-88: Sherritt Gordon Mines Ltd. carried out geological, geochemical and geophysical surveys, trenching, and diamond drilling (2 DDH totaling 260.1 m). 1997: D. Saunders carried out trenching. 2003: Kodiak Exploration Ltd. optioned the property from Cameco. 2004-6: Kodiak Exploration Ltd. carried out airborne and ground geophysical surveys, prospecting, mapping, stripping, sampling, and diamond drilling.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wabigoon

Terrane: Eastern Wabigoon

Belt: Onaman-Tashota

Geological Age: Archean  

Geology Comments

Dec 04, 2018 (Therese Pettigrew) - The greater Vent property is located within Neoarchean mafic to felsic metavolcanic rocks of the Onaman-Tashota greenstone belt within the Wabigoon subprovince. Common lithologies include rhyolite, rhyodacite, rhyolite porphyry, pyroclastic breccia, sericite schist and massive to pillowed basalt. The central portion of the property contains gabbroic intrusions with disseminated sulphides, as well as quartz and carbonate veins along contacts with pre-existing metavolcanics (White et al., 2013).

Lithology

Mineralization

Mineralization Comments

Dec 04, 2018 (Therese Pettigrew) - A grab sample collected by Resident Geologist Staff from within this unit returned 0.995 g/t Au and 77 g/t Ag. Quartz veining and brecciated sulphide lenses averaging 1 cm in width were also noted at one location (White et al., 2014). A property report by Roach (2013) described the Vent occurrence as: “part of a 2.5 km by 0.5 km Na2O depletion alteration zone in QP (quartz porphyry) with hydrothermal jigsaw or crackle breccias. The breccia exhibits advanced argillic to phyllic alteration with intense silica flooding and sulphidation.” Drilling results by Kodiak Exploration Limited in 2005 returned anomalous gold values up to 0.72 g/t Au (Assessment file 20000001962). The zone is open down-plunge 65° to 70° to the north and down-dip where the inferred deeper part of the [VMS] boiling system has been interpreted (White et al., 2014). Cataclastic foliation developed along fractures, shears, and faults. This type of foliation is easily recognized in the field by the occurrence of chlorite and sericite schist. The Vent area is one of the best examples and consists of a highly weathered gossan and sheared quartz porphyry rock containing over 10% sericite, quartz, plagioclase, over 5% pyrite, and about 1% pyrrhotite. Results of assays on selected grab samples indicated trace amounts of gold, tin, lead, chromium and titanium. One sample returned assays of 0.23% Cu and 6.19 opt Ag (Amukun, 1976). The Vent alteration system is typified by widespread and intense sodium-depletion and pyritization within the quartz porphyry intrusion. An area of Au-Ag mineralization containing values of up to 2.68 g/t Au over a channel length of 0.62 m, 1.01 g/t Au over a channel length of 1.66 m, and 107 g/t silver and 0.59% Cu over a channel length of 0.44 m was discovered by mechanical stripping and channel sampling during 2004 (Assessment file 20000000550).

Mineral Record Details

Site Visit Information

Date: Jun 06, 2013

Geologist: Robert Cundari

Notes: The Vent occurrence lies within a prominent north-trending area of sodium depletion identified by Kodiak Exploration Limited in 2004. The site was visited by staff of the Thunder Bay North Resident Geologist office in June 2013. An area of approximately 50 by 80 m was exposed by stripping in 2004 to reveal prominent heavy, orange to red patchwork gossan, indicative of iron carbonate alteration. Hosted within this rusty zone is a unit of intensely silicified “spider web-fractured” and pitted, fine-grained quartz feldspar porphyry (QFP). The QFP contains up to 1% finely disseminated pyrite. According to property owner and consulting geologist S. Roach, samples averaged from 0.2 to 7 g/t Au over 2 to 11 m and have ranged up to 11.88 g/t Au. Three mineralized lenses are exposed over a 230 m strike length (S. Roach, personal communication, 2013).

References

Folio - Metcalfe Lake area, District of Thunder Bay

Publication Number: GDIF024 Scale:     Date: 1997

Author: Thunder Bay RGO

Publisher Name: Ontario Geological Survey

Location:

Map - Tashota, Thunder Bay District

Publication Number: M2354 Scale: 1:31,680    Date: 1976

Author: Amukun S.E.

Publisher Name: Ontario Division of Mines

Location:

MonoMap - Geology of the Tashota area, District of Thunder Bay

Publication Number: R167 Scale:     Date: 1977

Author: Amukun S.E.

Publisher Name: Ontario Geological Survey

Location:

Mono - Report of Activities 2013, Resident Geologist Program, Thunder Bay North Regional Resident Geologist Report: Thunder Bay North District

Publication Number: OFR6292 Scale:     Date: 2014

Author: White G.D., Cundari R.M., Tuomi R.D., Brunelle M.R., Debicki R.L., Moses P., Zurevinski S.E.

Publisher Name: Ontario Geological Survey

Location:

Report an Error

We are continuously updating our assessment file / technical report information. If you notice errors in the data, please contact us.

Terms of Use

Please review our Terms of Use agreement for this data product.

Ministry Contact Information

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