Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI42D01SE00001

Record: MDI42D01SE00001

General

Commodities

Primary Commodities: Uranium, Thorium, Beryllium, Vanadium, Yttrium

Secondary Commodities: Chromium, Zircon, Rubidium

Location

Township or Area: Walsh

Latitude: 48° 50' 30.18"    Longitude: -86° 40' 24.89"

UTM Zone: 16    Easting: 523950.68   Northing: 5409911.94    UTM Datum: NAD83

Resident Geologist District: Thunder Bay South

NTS Grid: 42D15NE

Point Location Description: Central point between the mapped North, Centtral, and South diatremes.

Location Method: Based on Assessment

Access Description: The Dead Horse Creek diatreme complex is located in Walsh Township approximately 4 km north of Highway 17 along the Dead Horse Creek access road. The road intersects Highway 17 approximately 26 km northwest of the town of Marathon. Access is via Highway 17 and north on the Dead Horse Creek access road for 4.0 km.

Exploration History

1977: Gulf Minerals Canada Ltd. staked a claim group to cover a radioactivity anomaly. Limited prospecting was completed. 1978: Gulf Minerals Canada Ltd. completed geological mapping and diamond drilling (8 holes). 1981: Gulf Minerals Canada Ltd. completed one diamond drill hole (130.1 m). 1982: Property re-staked by D.O. Walsten. No work recorded. 1984: Property re-staked by O. Belisle. 1985: Property optioned to Highwood Resources who mapped out a diatreme breccia into five discrete sub-complexes. Highwood conducted a soil and scintillometer survey on a 50 m-spaced grid plus re-logged the Gulf drill core and reassayed 71 core samples for Be, Y and Ce. Property returned to O. Belisle. 1987: Unocal Canada Ltd. optioned the property from Jet Exploration-O. Belisle. An exploration program of geological mapping, soil geochemistry, stripping, and geophysics (Magnetometer and Radiometric) surveys were completed. 1988: Unocal Canada Ltd. relogged and sampled the Gulf Minerals Canada Ltd. diamond drill holes and carried out channel sampling. 1991: Unocal Canada Ltd. returned the property to O. Belisle. 2008: J. Ternoskwsky staked the property. 2009: Canadian International Minerals Inc. optioned the property. 2010: Canadian International Minerals contracted Fugro Airborne Surveys to fly a high resolution magnetic and radiometric survey. 2011: Canadian International Minerals completed prospecting, geological mapping, rock sampling, spectrometer (radiometric) surveys, trenching and channel sampling.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wawa

Terrane: Wawa-Abitibi

Belt: Schreiber-Hemlo

Geological Age: Archean   Geochronological Age: Smyk (unpublished)   Geochron. Age Ref.: 1128.7 +/- 6 Ma

Geology Comments

Dec 07, 2005 (A Mitchell) - The Dead Horse complex has maximum dimensions of 1600 by 400 m, and is elongated in a north-northeast direction. The breccia consists of angular to subrounded clasts of locally derived rocks in a matrix of comminuted rock debris which has been locally extensively altered. Clasts up to 1 m have been seen, but most frequently they are 0.3 m or less. The alteration is extremely variable within the breccia. The first indication of alteration is reddening of clast margins. With more intense alteration, the entire clast is bright brick red and hard to break. Such extensively replaced clasts break with a crude conchoidal fracture. The extensively altered breccias are generally highly radioactive. In the southwest corner and at the west contact of the South Dead Horse subcomplex, are isolated, highly radioactive outcrops of breccia with a carbonate matrix. These outcrops consist dominantly of fine-grained, grey carbonate with isolated red clasts weathering 4 to 5 cm in relief. The clasts have an open framework supported by the carbonate matrix. A lamprophyre dike rich in carbonate cuts the breccia in the face of a cliff in the southwest corner of the complex. In the, northeast corner of the south subcomplex is an extensive zone of scapolite replacement. The clasts are not red, but grey on weathered surface. This zone is appreciably more radioactive than the highly altered red breccia. Carbonate, amphibole, and disseminated pyrite are common in the matrix of the scapolite zone, and form part of the replacement mineralogy. The complex has been cut by dikes of carbonate, diabase, porphyritic trachytoidal diabase, and syenite aplite. Rb-Sr isochron dating by Bell et al. (1970) indicates an isotope age of 1085?15 Ma for the Port Coldwell complex, establishing a maximum age for the diatreme since monzonite occurs as clasts within the breccia.

Lithology

Lithology Comments

Dec 07, 2005 (A Mitchell) - The Main Mineralized Zone (MMZ) is a composite unit that comprises diverse, hydrothermally altered and rare-metal mineralized rocks. It is steeply dipping, curved to tabular zone 82 m long, averaging 1.5 m in width, and is apparently closed at both ends (Knox, 1987). Diamond drilling has intersected the MMZ at depth but it is poorly mineralized. The structure in which the MMZ is situated crosscuts the diatreme breccia, is exposed for 140 m and may continue under overburden. As first described by Knox (1987), the MMZ consists of strongly hematitized and silicified rocks, presumably of Archean age, which have been fractured, brecciated and veined by quartz. Patchy carbonate also occurs along the zone's margins. Where hosted by diatreme breccia, the MMZ consists of irregular, anastomosing quartz veins and vein-breccias in a hematitized host. Pink grains of phenakite are visible in these quartz veins and pods. Rare-metal mineralization within the MMZ is erractically distributed. The highest grade, most strongly radioactive zones are distinguishable in the field as hard, chocolate-brown, massive, fine-grained rocks with a conchoidal fracture.

Mineralization

Mineralization Comments

Dec 07, 2005 (A Mitchell) - The Dead Horse Creek structure has the greatest economic potential of any diatreme structures yet identified on the north shore of Lake Superior. The author has obtained spectrometer readings 10 times background in some areas. Thorium appears to dominate over uranium. A selected group of samples was submitted for analysis which disclosed anomalous quantities of uranium, thorium, rare earths, beryllium, and in one instance zirconium. Base or precious metals previously reported by Fenwick and Scott (1978) were not found in significant quantities. The silver-lead mineralization reported by Fenwick and Scott (1978) was likely from an accidental clast of mineralized rock derived from lead-silver-zinc veins that cut the Early Precambrian rocks of the area (Walker 1967). With perhaps the exception of beryllium, the anomalous metal contents are diagnostic or characteristic of a carbonatite. Sage (1982) continues describing the mineralogy as: Comparison of minor element abundance in the Dead Horse Creek diatreme and its wall rocks show that in addition to U, Th and Be, other elements (Ba, Sr, Nb, Pb, rare earths, phosphorous, and titanium) are enriched in the diatreme. The anomalous niobium, rare earths, phosphorous, and titanium imply a relationship to alkalic rock-carbonatite magmatism. Erratic, but slightly higher Pb, V, Co and Mo are indicated. Chromium and zinc appear relatively the same, and copper values are erratic. Lithium and possibly nickel appear depleted. The main mineral constituent of the Main Mineralized Zone is a fine-grained, calcium zirconosilicate. Zircon, uraninite, thorite, monazite-(Ce) and xenotime-(Y) also have been identified. Riebeckite is common peripheral to the zone in the diatreme breccia (Smyk et al. 1993).

Jun 21, 2017 (Therese Pettigrew) - Scott (1987) reported the following results from sample JS-U-82-1: 0.94% Be, 470 ppm Sr, 2180 ppm V, 900 ppm Yt, 5-15% Zr, 930 ppm Ba, 88 ppm Zn, 1450 ppm Cr, 10 ppm Co, 181 ppm Cu, 1900 ppm U. The following were results from sample JS-U-82-2: 0.2% Be, 410 ppm Sr, 560 ppm V, 535 ppm Yt, 5-15% Zr, 6120 ppm Ba, 59 ppm U, 10 ppm Th, 90 ppm Rb. Uranium assays included values of 1600 ppm, 1900 ppm, 2900 ppm, and 0.32% U. Thorium assays included results of 2900 ppm, 5000 ppm, and 1% Th.

Alteration Comments

Jan 24, 2017 (A Mitchell) - As first described by Knox (1987), the MMZ consists of strongly hematitized and silicified rocks, presumably of Archean age, which have been fractured, brecciated and veined by quartz. Patchy carbonate also occurs along the zone's margins. Where hosted by diatreme breccia, the MMZ consists of irregular, anastomosing quartz veins and vein-breccias in a hematitized host. Pink grains of phenakite are visible in these quartz veins and pods. Rare-metal mineralization within the MMZ is erractically distributed. The highest grade, most strongly radioactive zones are distinguishable in the field as hard, chocolate-brown, massive, fine-grained rocks with a conchoidal fracture.

Mineral Record Details

References

Journal - Geology and geochemistry of the West Dead Horse Creek rare-metal occurrence, northwestern Ontario

Publication Number: EMG Vol 2 No 3 Page: 245-251  Date: 1993

Author: Smyk, M.C., Taylor, R.P., Jones, P.C., Kingston, D.M.

Publisher Name: Exploration and Mining Geology, Volume 2, Number 3

Location:

Publication - Dead Horse Creek Rare Earth Project, Walsh Township Northern Ontario

Publication Number: NI 43-101 Date: 2009

Author: Arseneau, G., Elliot, C.

Publisher Name: SRK for Canadian International Minerals Inc.

Location: SEDAR

Thesis - The Rare and Exotic Mineralogy of the Western Subcomplex of the Deadhorse Creek 'Diatreme', Northwestern Ontario

Publication Number: MSc Thesis Date: 2004

Author: Potter, E.G.

Publisher Name: Lakehead University

Location: https://knowledgecommons.lakeheadu.ca/jspui/bitstream/2453/4062/1/PotterE2004m-1a.pdf

Journal - Mineralogy of the Deadhorse Creek Volcaniclastic Breccia Complex, Northwestern Ontario, Canada, pp 212–229.

Publication Number: Volume 150, 2 Date: 2005

Author: Potter, E., Mitchell, R.

Publisher Name: Contributions to Mineralogy and Petrology

Location:

Mono - Mineralization in diatreme structures north of Lake Superior

Publication Number: S027 Date: 1982

Author: Sage R.P.

Publisher Name: Ontario Geological Survey

Location:

MonoMap - Geology of the Jackfish-Middleton area, District of Thunder Bay

Publication Number: R050 Date: 1997

Author: Walker J.W.R.

Publisher Name: Ontario Dept. of Mines

Location:

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

Publication Number: OFR5634 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