Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI42D15NE00005

Record: MDI42D15NE00005

General

Commodities

Primary Commodities: Niobium, Amethyst

Secondary Commodities: Rare Earth Elements

Location

Township or Area: Foxtrap Lake Area

Latitude: 48° 59' 12.91"    Longitude: -86° 41' 59.97"

UTM Zone: 16    Easting: 521949   Northing: 5426045    UTM Datum: NAD83

Resident Geologist District: Thunder Bay South

NTS Grid: 42D15NE

Point Location Description: Small pit.

Location Method: Field Visit

Access Description: The occurrence straddles the western branch of the Dead Horse Creek forest access road, approximately 5 km north of Foxtrap Lake. The occurrence is situated approximately 23 km north along the Dead Horse road from its junction with Highway 17, 30 km west of Marathon. The showings are exposed in a gravel pit on the east side of the road, and in a cleared area to the west of the road.

Exploration History

1978: Trenching and blasting; prospector N. Hibbart. 1979: Property examination, radiometric survey and lithogeochemical sampling by OGS Staff member J.F. Scott. 1990: Property examination and lithogeochemical sampling by OGS staff.

Geology

Province: Superior

Subprovince: Wawa

Terrane: Wawa-Abitibi

Geological Age: Archean  

Geology Comments

Dec 07, 2005 (D McKay) - The following geological description is a synthesis of notes taken by J. Scott in 1979 (Resident Geologist's Files, Thunder Bay) and recent field work. The area is underlain predominantly by syenitic and granitic rocks which are brecciated, cut by small, anastomosing quartz veinlets and hematitized along fractures in the vicinity of a hematite-rich syenite dyke. The dyke is usually a massive, fine-grained pink rock with closely spaced joints, some of which are filled with calcite. It is approximately 5 m wide, strikes at 120 and dips 20 to the north. Sections of the dyke are strongly fractured, brecciated in-situ and hematitized. Angular white quartz fragments are cemented by massive hematite. Other brecciated sections contain rounded, rebrecciated xenoliths in a coarser-grained, igneous matrix. Marginal to the main dyke, smaller, variably oriented, syenitic to aplitic dykes intrude crenulated biotite schists and granitic rocks to the north and south, respectively. The biotite schists, interpreted as migmatitic metasedimentary rocks, are epidotized and hematitized along fractures. A small pit has been sunk on a 20 cm wide quartz vein and flat-lying, parallel quartz veinlets approximately 25 m north of the main dyke. The vein is heavily mineralized with fine-grained, net-textured pyrite. Gossanous outcrops occur along strike with the main dyke. Radiation at these showings were estimated to be 3 to 4 times the background level. On the west side of the road, a 20 m wide diabase dyke strikes at 170 and intrudes granitoid rocks. There are no outcrop exposures of the syenite dyke, but along strike, gossanous, carbonate-rich, sandy regolith has developed.Landsat satellite images reveal several northwest-striking faults in the area. The Kilometre 23 dyke is perhaps related to these structures.

Lithology

Lithology Comments

Dec 07, 2005 (D McKay) - The area is underlain predominantly by syenitic and granitic rocks which are brecciated, cut by small, anastomosing quartz veinlets and hematitized along fractures in the vicinity of a hematite-rich syenite dyke. The dyke is usually a massive, fine-grained pink rock with closely spaced joints, some of which are filled with calcite. It is approximately 5 m wide, strikes at 120 and dips 20 to the north. Sections of the dyke are strongly fractured, brecciated in-situ and hematitized. Angular white quartz fragments are cemented by massive hematite. Other brecciated sections contain rounded, rebrecciated xenoliths in a coarser-grained, igneous matrix. Marginal to the main dyke, smaller, variably oriented, syenitic to aplitic dykes intrude crenulated biotite schists and granitic rocks to the north and south, respectively. The biotite schists, interpreted as migmatitic metasedimentary rocks, are epidotized and hematitized along fractures.

Mineralization

Mineralization Comments

Dec 07, 2005 (D McKay) - A small pit has been sunk on a 20 cm wide quartz vein and flat-lying, parallel quartz veinlets approximately 25 m north of the main dyke. The vein is heavily mineralized with fine-grained, net-textured pyrite. Gossanous outcrops occur along strike with the main dyke. Radiation at these showings were estimated to be 3 to 4 times the background level. On the west side of the road, a 20 m wide diabase dyke strikes at 170 and intrudes granitoid rocks.There are no outcrop exposures of the syenite dyke, but along strike, gossanous, carbonate-rich, sandy regolith has developed. Euhedral crystals of smoky to amethystine quartz have been recovered from this unconsolidated material. Crystals with pyramidal terminations and doubly terminated, penetration twins may reach 4 cm in size. It is suggested that this regolith has resulted from the deep weathering of vuggy, quartz-carbonate-hematite-rich sections of the dyke and/or brecciated portions therein. Grab sampling of gossanous outcrops by J. Scott for the OGS in 1979 returned the following assays: Sample No.F-150-79: 37 U (ppm), 40 Th (ppm), 2500 Zr (ppm), 10 Be (ppm), 700 Nb (ppm). Sample No.F-151-79: 24 U (ppm), 30 Th (ppm), 500 Zr (ppm), 5 Be (ppm), 600 Nb (ppm). Sample No.F-152-79: 14 U (ppm), 130 Th (ppm), 300 Zr (ppm), 4 Be (ppm), 1000 Nb (ppm). A grab sample of the dark, massive quartz vein with net-textured pyrite collected from the pit by the SH Resident/Staff Geologist in 1990 assayed nil Au, nil Ag and 0.034% Cu.

Alteration Comments

Dec 07, 2005 (D McKay) - The area is underlain predominantly by syenitic and granitic rocks which are brecciated, cut by small, anastomosing quartz veinlets and hematitized along fractures in the vicinity of a hematite-rich syenite dyke. Marginal to the main dyke, smaller, variably oriented, syenitic to aplitic dykes intrude crenulated biotite schists and granitic rocks to the north and south, respectively. The biotite schists, interpreted as migmatitic metasedimentary rocks, are epidotized and hematitized along fractures.

Mineral Record Details

Mineral Zones - Size and Shape

Site Visit Information

Date: May 01, 1997

Geologist: R Degagne

Notes: Visited in May, 1990 by P. Hinz, and R. M. Landry (OGS OFR 5889, 1994). COMMENTS/RECOMMENDATIONS: This amethyst occurrence is notably the farthest east of any amethyst occurrences in the Schreiber-Hemlo District.

References

Map - Nipigon-Schreiber, geological compilation series, Thunder Bay District

Publication Number: M2232 Scale: 1:253,440    Date: 1973

Author: Carter M.W., McIlwaine W.H., Wisbey P.A.

Publisher Name: Ontario Division of Mines

Location:

Mono - Mineral Occurrences in the Nipigon-Marathon Area, Volumes 1 and 2.

Publication Number: OFR5951 Page: 547-549  Date: 1996

Author: Schnieders B.R., Smyk M.C., Speed A.A., McKay D.B.

Publisher Name: Ontario Geological Survey

Location:

Mono - Industrial Mineral Occurrences and Deposits in Northwest Ontario

Publication Number: OFR5889 Page: 78-81  Date: 1994

Author: Hinz P., Landry R.M.

Publisher Name: Ontario Geological Survey

Location:

Article - Schreiber-Hemlo Resident Geologist's District - 1990

Publication Number: MP152.007 Page: 166  Date: 1997

Author: Schnieders B.R., Smyk M.C., Hinz P.

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