Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI52A15SE00019

Record: MDI52A15SE00019

General

Commodities

Primary Commodities: Uranium

Location

Township or Area: Dorion

Latitude: 48° 47' 53.83"    Longitude: -88° 43' 56.57"

UTM Zone: 16    Easting: 372781   Northing: 5406480.01    UTM Datum: NAD83

Resident Geologist District: Thunder Bay South

NTS Grid: 52A15SE, 52A15SW

Point Location Description: J. Scott field visit with GPS, DDH SS-10-005 location

Location Method: Data Compilation

Access Description: The area is located in northwestern Dorion Township, approximately 55 km northeast of Thunder Bay. Access is by an all-weather gravel road that intersects Highway 11/17 approximately 65 km east of Thunder Bay. The showing is located 4 km south of Innes Lake and 4 km west of Ouimet Canyon.

Exploration History

1968: B. Halverson found the occurrence while prospecting and conducted stripping and trenching. 2006: Antoro Resources Inc. conducted prospecting and a radiometric survey. 2007: Benton Resources Corp. flew an airborne geophysical survey. 2008: Benton Resources conducted soil sampling. 2010: Benton Resources drilled 5 DDH totalling 990 m.

Assessment Work on File

Geology

Province: Superior

Subprovince: Quetico

Terrane: Quetico Basin

Geological Age: Archean  

Geology Comments

Jun 21, 2017 (Therese Pettigrew) - This claim straddles the Good Morning Lake Fault. The fault strikes N30W and predates Late Precambrian fractures which strike N60E (Robertson and Gould, 1983).

Lithology

Lithology Comments

Jun 21, 2017 (Therese Pettigrew) - In the Innes Lake-Goodmorning Lakes area, the Quetico Belt migmatitic rocks contain uranium-bearing pegmatites. These occur just SW of Innes Lake in Dorion Township. The pegmatite dikes are irregular in shape, elongated in an east-west direction, and more or less parallel to the regional strike of the migmatites. The dikes tend to pinch and swell along their strike direction. Some pegmatite pods are up to 200 m long and perhaps up to 120 m wide. (Scott, 1987). The Goodmorning Lake Fault zone is expressed in outcrop as a large breccia zone containing fine to coarse fragments. A bilaterally symmetrical zone of what appears to be hydrothermally-altered quartz monzonite envelopes this breccia. There is a gradational decrease in the degree of alteration, hematitization, and sericitization in outcrop from the breccia outwards into slightly altered quartz monzonite, typical of the surrounding region. Within the breccia unit there is a highly silicified central zone and all units mapped exhibit variable amounts of quartz veining (Yule, 1979).

Mineralization

Mineralization Comments

Jun 21, 2017 (J Scott) - 633 ppm U

Jun 21, 2017 (Therese Pettigrew) - Mineralization consists of uraninite in pegmatites and uraniferous fluorapatite in the fault zone. Two main types of uranium mineralization occur in the area. Syngenetic deposits of uranium occur in fresh, relatively unaltered pegmatite dykes, and epigenetic deposits occur in brecciated, hydrothermally altered rocks associated with the Goodmorning Lakes Fault Zone. In the Innes Lake-Goodmorning Lakes area, the Quetico Belt migmatitic rocks contain uranium-bearing pegmatites. These occur just SW of Innes Lake in the area of Lot 13, Concession XI, Dorion Township. The pegmatite dykes are irregular in shape, elongated in an east-west direction, and more or less parallel to the regional strike of the migmatites. The dykes tend to pinch and swell along their strike direction. Some pegmatite pods are up to 200 m long and perhaps up to 120 m wide.The pegmatites are medium- to coarse-grained and white to greyish white in color. Mineralogy of the dykes appears to be simple: feldspar (albite), quartz, biotite ± apatite ± accessories such as zircon. Secondary uranophane is often seen on fracture surfaces. Highest radiation as detected with a gamma ray spectrometer is invariably associated with the more mafic sections of the pegmatites. Approximately thirty trenches were blasted in the pegmatite zones in 1968, and grab samples ranged up to 0.18% uranium (John Ternowesky, prospector, Thunder Bay, personal communication, 1981). One sample collected by the author analysed 160 ppm uranium and 800 ppm thorium (Analysis by Geoscience Laboratories, Ontario Geological Survey, Toronto, Ontario). In mineralized samples, there exists a high correlation between concentrations of uranium and phosphorous that suggests that the uranium occurs in association with apatite or an unidentified uranium phosphate mineral (Scott, 1987). Yule (1979) collected samples that assayed up to 633 ppm U3O8.

Mineral Record Details

References

Article - 1979 report of North Central Regional Geologist

Publication Number: MP091.004 Page: 46  Date: 1997

Author: Fenwick K.G., Larsen C.R., Scott J.F., Mason J.K., Schnieders B.R.

Publisher Name: Ontario Geological Survey

Location:

Thesis - Investigations of the Good Morning Lake Radioactive Fault Breccia: Innes Lake Area, Dorion Township, Northwestern Ontario

Publication Number: BSc Thesis Date: 1979

Author: Yule, G.R.

Publisher Name: Lakehead University

Location: Thunder Bay RGP

Mono - Uranium and thorium deposits of northern Ontario

Publication Number: MDC025 Page: 128  Date: 1984

Author: Robertson J.A., Gould K.L.

Publisher Name: Ontario Geological Survey

Location:

Mono - Uranium occurrences of the Thunder Bay-Nipigon-Marathon area

Publication Number: OFR5634 Page: 83-95  Date: 1987

Author: Scott J.F.

Publisher Name: Ontario Geological Survey

Location:

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