Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI42E13SE00013

Record: MDI42E13SE00013

General

Commodities

Primary Commodities: Copper

Secondary Commodities: Zinc, Lead, Silver, Gold

Location

Township or Area: Elmhirst

Latitude: 49° 46' 30.18"    Longitude: -87° 38' 27.52"

UTM Zone: 16    Easting: 453849.15   Northing: 5513817.28    UTM Datum: NAD83

Resident Geologist District: Thunder Bay North

NTS Grid: 42E13SE

Point Location Description: Pits and trenches.

Location Method: Conversion from MDI

Access Description: The claims are located in southeastern Elmhirst Township. The main showing is located on claims TB303240 about 650 m west of the west township boundary and approximately 2.4 km north of the south boundary. Follow secondary highway 801 north from Nezah (10.1 km west of Jellico) and northeast on a lumber road for about 9.7 km.

Exploration History

1971: Properties covering the occurrence were staked by Arthur J. Douglas. A number of pits and trenches were dug before the claims were optioned to Cerro Mining Company of Canada Ltd. 1971-73: Cerro conducted geological, ground EM and mag surveys, and dug six trenches. The claims were later cancelled. 1976-1981: Properties staked and restaked a number of times. 1983: Mag and EM surveys conducted by John S. Grant. 1984: Geological and geochemical surveys were conducted by the Elmhirst Lake Syndicate. 2009: Alto Ventures Ltd. carried out prospecting and sampling.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wabigoon

Terrane: Eastern Wabigoon

Belt: Onaman-Tashota

Geological Age: Archean  

Geology Comments

Dec 07, 2005 (B Nelson) - Most of the claims are underlain by felsic to intermediate coarse pyroclastic rocks such as tuff breccia, lapilli tuff, and crystal tuff. The metavolcanics strike at about N70E and dip quite steeply to the south. Patches of gossan covering the felsic metavolcanics are common, and in some places pyrite forms as much as 10% of the rock. In Pit 5, massive cp and py occur in quartz-sericite schist over a width of 0.18 m. The sulphide mineralization is concordant with the schistosity. The second most interesting occurrence is Pit 1, where stringers of cp, py and po occur in the chlorite schist, at the contact of the schist with fragmental felsic metavolcanics, across a width of 1.34 m. Trench B, located 13.5 m southwest of Pit 1, exposed a narrow lense of high grade cp located 2 m north of the south end of the trench. A narrow shear zone, consisting of chlorite-quartz schist, carries lenses of cp and minor py. The sulphides comprise 10-30% of the shear zone material. The zone strikes N55E and dips 65 degrees S. A silicified zone 15 cm wide borders the chlorite-quartz schist and carries traces of chalcopyrite. A small quartz vein 15 cm wide and having an exposed length of about 30 cm occurs south of and sub-parallel to the chlorite-quartz schist. The exposed veins material is barren, but quartz-vein rubble from the trench carries large patches of cp and py.

Lithology

Lithology Comments

Dec 07, 2005 (B Nelson) - Most of the claims are underlain by felsic to intermediate coarse pyroclastic rocks such as tuff breccia, lapilli tuff, and crystal tuff.

Mineralization

Mineralization Comments

Dec 07, 2005 (B Nelson) - A chip sample across the Pit 5 schist zone assayed 3.32 % Cu, 0.08% Zn, 0.01 oz/ton Au, and 0.43 oz/ton Ag. A chip sample across the Pit 1 schist zone assayed 0.70% Cu, 0.03% Zn, trace Au, and trace Ag. A grab sample assayed 0.81% Cu and 0.04% Zn.

Dec 18, 2020 (Therese Pettigrew) - From the Cerro Pit 1 area, Sample 755248 collected by Alto Ventures in 2009 returned 44,810 ppm (4.481% Cu) from biotite-chlorite schist containing 10% chalcopyrite in coarse blobs up to 2 cm, 5% pyrite associated with the chalco blebs. Sample 755250 returned 17,298 ppm Cu from a chlorite schist with 5% pyrite, 1% chalcopyrite, and malachite staining. From the Cerro Pit 3 area, Sample 755215 collected by Alto Ventures in 2009 returned 15,018 ppm Cu (1.502% Cu) and 2450 ppm Zn from a chlorite schist with quartz veining, 7-10% chalcopyrite, 1-2% pyrite, and moderate malachite staining. Sample 755216 returned 0.109 ppm Au, 10,391 ppm Cu, 13,176 ppm Pb, and 21,144 ppm Zn from quartz veining in a chlorite schist with 3-5% disseminated chalcopyrite, 2-3% disseminated pyrite, and 0.1-0.5% finely disseminated galena (Assessment report 20000006225).

Mineral Record Details

References

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

Publication Number: M2102 Scale:     Date: 1997

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

Publisher Name: Ontario Dept. of Mines

MonoMap - Geology of Elmhirst and Rickaby townships, District of Thunder Bay

Publication Number: R168 Scale:     Date: 1978

Author: Mackasey W.O., Wallace H.

Publisher Name: Ontario Geological Survey

Map - Elmhirst and Rickaby townships, Thunder Bay District

Publication Number: M2373 Scale: 1:31,680    Date: 1977

Author: Mackasey W.O., Wallace H.

Publisher Name: Ontario Geological Survey

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

Publication Number: OFR5630 Scale:     Date: 1986

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

Publisher Name: Ontario Geological Survey

Map - Thunder Bay data series, Wilkinson Lake area, District of Thunder Bay

Publication Number: P2514 Scale: 1:15,840    Date: 1982

Author: Speed A.A.

Publisher Name: Ontario Geological Survey

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