Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI42E10NW00049

Record: MDI42E10NW00049

General

Commodities

Primary Commodities: Gold, Copper, Silver

Secondary Commodities: Zinc, Molybdenum, Lead

Location

Township or Area: Croll, Ashmore

Latitude: 49° 41' 21.38"    Longitude: -86° 48' 52.04"

UTM Zone: 16    Easting: 513383   Northing: 5504100    UTM Datum: NAD83

Resident Geologist District: Thunder Bay North

NTS Grid: 42E10NW

Point Location Description: Sample G25904 from Assessment report 20000005341

Location Method: Data Compilation

Access Description: The occurrences are located in Ashmore and Croll Township. Follow the Eldee Lake Road south of Highway 11. The Eldee Lake Road originates 3.5 km east of the Ministry of Natural Resources District Fire Base Access Road.

Exploration History

1933-1940: A group of nine claims were staked west of Mineral Lake along the Ashmore-Croll Township line adjoining the Roche Longlac claims. A limited amount of stripping and trenching were conducted by Mat-A-Lac Gold Mines Limited in 1936. 1983: O. Theriault conducted power stripping and drilled 2 DDH totalling 72.8 m. 1984: O. Theriault carried out manual work and drilled 2 DDH totalling 80.8 m. 1990: M. Swereda drilled 1 DDH totalling 182.9 m. 1991: M. Swereda carried out geological mapping, VLF-EM and magnetic surveys. 1992: M. Swereda carried out prospecting, sampling and drilled 1 DDH totalling 88.7 m. 1994: M. Swereda carried out prospecting and sampling. 1996: M. Swereda drilled 1 DDH totalling 94.5 m. 2009-10: Kodiak Exploration Ltd. (renamed to Prodigy Gold Inc.) carried out prospecting and sampling. 2014: R. Hodgson carried out a VLF-EM survey, mapping and sampling.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wabigoon

Belt: Beardmore-Geraldton

Geological Age: Archean  

Geology Comments

Dec 07, 2005 (B Nelson) - Vein type mineralization in the Croll Lake Stock is present throughout the intrusion, although vein density is lowest in the north, intermediate in the south, and highest to the west in the 'nose'. Locally, veins may reach up to 1 m in width. In the nose of the stock, an extensive hydrothermal vein system is present, associated principally with the marginal porphyritic phases of the granite and found also in the adjacent mafic supracrustals. Vein density may reach in excess of 10 veins per metre, somewhat reminiscent of porphyry-type deposits in the Cordillera of Central and North America. Vein widths may reach in excess of 2 metres. The zone containing mo (with quartz,tourmaline, and locally epidote) is in excess of 1.5 km in diameter and is found both within the porphyritic margin of the stock and up to 1 km to the west of the contact, within the mafic metavolcanics. The 'old showing' is a pit on the west side of the Eldee Lake Road, sunk in a large quartz-tourmaline vein hosting pyrite. The 'new showing' is a sulphide zone hosting py and po in a mafic metavolcanic exposure on the east side of the Eldee Lake Road. The 'main showing' is located 0.8 km south of the highway on the east side of the Eldee Lake Road south of the Mininstry of Natural Resources scarification equipment storage yard, The 'main showing' is hosted in a contact area between diabase and mafic metavolcanics. Gold is associated with silicified zones of highly altered feldspar porphyry and/or banded chert.

Lithology

Lithology Comments

Dec 07, 2005 (B Nelson) - In many outcrops at the western end of the 'nose' region of the Croll Lake Stock, curious quartz, quartz-feldspar, or quartz-feldspar-tourmaline ovoids up to 2 cm in length may be found within the mafic rocks. At first sight, the ovoids appear to be similar to amygdules. Their marked spatial association with porphyritic dykes, their occurrence throughout pillows (as opposed to being zoned about the pillow centres), and the local occurrence of tourmaline within the ovoids suggests a more complex origin. This feature cross-cuts pillow selvages and is interpreted to be a form of incipient metasomatic alteration of the mafic rock.

Mineralization

Mineralization Comments

Dec 07, 2005 (B Nelson) - The sulphide assemblage includes py, po, cp and mo. The zone containing mo (with quartz, tourmaline and, locally, epidote) is in excess of 1.5 km in diameter and is found both within the porphyritic margin of the stock and up to 1 km to the west of the contact, within the mafic metavolcanics. Of the samples taken in 1984, the majority returned values of <0.01 to 0.01 oz/ton Au. The high assay was 0.08 oz/ton Au, taken from a highly weathered and gossaned, massive coarse euhedral pyrite-rich zone intermixed with vitreous quartz veining.

Jul 26, 2019 (Therese Pettigrew) - Swereda described Zone 1 as a well-defined fault shear system that is variably carbonatized, quartz veined, chloritized and locally sericitic. It is about 1.5-3 m wide and exposed along strike for about 107 m. Pyrite occurs variably along its length. Chalcopyrite is spotty and appears to be most heavily concentrated in thicker quartz veins. The best assays returned up to 2.434 ppm Au and 1.54% Cu (Assessment report 42E10NW0004). Swereda reported visible gold in a sample collected in 1994 (Assessment report 42E10NW0002). The best assays from DDH CR-96-1 was 1568 ppm Cu and 1.414 ppm Au (Assessment report 42E10NW0006). Highlights from the 2009 sampling program of the Rubber Tire Zone (RTZ) included up to 14.2 g/t Au, 77.5 g/t Ag, 5.77% Cu and 0.09% Mo from grab samples. The Smoking Gun zone returned up to 5.09 g/t Au, 53.8 g/t Ag, 2.20% Cu, and 0.07% Mo from grab samples (Assessment report 20000006338).

Alteration Comments

Dec 07, 2005 (B Nelson) - In the 'main showing', gold is associated with silicified zones of highly altered feldspar porphyry and/or banded chert.

Mineral Record Details

Site Visit Information

Date: Jan 14, 1997

Geologist: B Nelson

Notes: The Beardmore-Geraldton Economic Geologist visited the property September 15, 1983, and September 19, 1984.

References

Article - A re-appraisal of the Geraldton gold camp

Publication Number: MP116.043 Page: 194-197  Date: 1997

Author: Macdonald A.J.

Publisher Name: Ontario Geological Survey

Location:

Map - Long Lake-Pagwachuan Lake area, District of Thunder Bay, Ontario

Publication Number: ARM46B Scale: 1:63,360    Date: 1997

Author: Fairbairn H.W., Macdonald R.D.

Publisher Name: Ontario Dept. of Mines

Location:

Map - Township of Ashmore, District of Thunder Bay, Ontario

Publication Number: M1951-02 Scale: 1:12,000    Date: 1997

Author: Horwood H.C., Pye E.G.

Publisher Name: Ontario Dept. of Mines

Location:

Mono - Gold occurrences, prospects, and deposits of the Beardmore-Geraldton area, districts of Thunder Bay and Cochrane

Publication Number: OFR5630 Page: 421-427, 640-646  Date: 1986

Author: Mason J.K., White G.D.

Publisher Name: Ontario Geological Survey

Location:

Part - Geology of the northern Long Lake area

Publication Number: ARV46-03.001 Date: 1997

Author: Fairbairn H.W.

Publisher Name: Ontario Dept. of Mines

Location:

Map - Tashota-Geraldton sheet, geological compilation series, Thunder Bay and Cochrane districts

Publication Number: M2102 Date: 1997

Author: Pye E.G., Harris F.R., Fenwick K.G., Baillie J.

Publisher Name: Ontario Dept. of Mines

Location:

Part - Geology of Ashmore Township

Publication Number: ARV60-05 Date: 1997

Author: Horwood H.C., Pye E.G.

Publisher Name: Ontario Dept. of Mines

Location:

File - Resident Geologist Mineral Deposit Files

Publication Number: Min Dep Date: 1996

Author:

Publisher Name:

Location: Thunder Bay RGP

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