Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI52O06NE00004

Record: MDI52O06NE00004

General

Commodities

Primary Commodities: Gold

Location

Township or Area: Dobie Lake Area

Latitude: 51° 22' 52.53"    Longitude: -91° 13' 38.18"

UTM Zone: 15    Easting: 623365   Northing: 5693715    UTM Datum: NAD83

Resident Geologist District: Thunder Bay North

NTS Grid: 52O06NE

Point Location Description: OFR5869 p. 160

Location Method: Conversion from MDI

Access Description: The Dobie Zone is located about 71 km west of Pickle Lake and about 500 m east of Tonsil Lake (local name for the first lake downstream on the Dobie River from Dorothy Lake). Tonsil Lake is marginal for float and ski equipped aircraft. Helicopter access of this occurrence is recommended.

Exploration History

1960-80: Umex and Inco conducted airborne and ground geophysical surveys and limited diamond drilling for base metals in the mid-1970s. UMEX subsequently drilled on the Dobie Zone. 1986: Geocanex Ltd. and St. Joe Canada Inc. commissioned separate airborne mag and EM surveys over areas including the Dobie Zone. 1986: St. Joe Canada Inc. did ground mag, EM and IP surveys on the Dobie Grid and drilled the initial holes intersecting the Dobie Zone. 1987: St. Joe Canada Inc. did diamond-drilling on the Dobie Zone. 1988: Bond Gold Canada Inc. did additional geophysical surveys and geological mapping in the area and completed additional drill holes. 1990: Bond Gold Canada Inc. did further diamond- drilling. 2006: Canadian Golden Dragon Resources Ltd. conducted geological mapping. 2007: Canadian Golden Dragon conducted prospecting. 2008: the property was transferred to Trillium North Minerals Ltd.

Assessment Work on File

Geology

Province: Superior

Subprovince: Uchi

Terrane: North Caribou

Domain: Uchi

Belt: Meen-Dempster

Geological Age: Neoarchean  

Geology Comments

Dec 07, 2005 (B Nelson) - This occurrence consist of what Bond Gold Canada Inc. refers to as the Dobie Zone and the Dobie North Zone. The Dobie North Zone is located about 100 m north of the Dobie Zone towards the latter's west end. The Dobie Zone and the Dobie North Zone are hosted in a succession of mafic metavolcanic flows and tuffs with interbeds of iron formation. The succession is cut by quartz-feldspar porphyry dykes. Both zones trend southeast and dip north. They are characterized by strong shearing, silicification, carbonatization and sericitization. They are mineralized with up to 8% pyrite and pyrrhotite with traces of chalcopyrite and arsenopyrite. The sulphides occur as massive bands, stringers, blebs and disseminations.

Mar 10, 2015 (Therese Pettigrew) - The Dobie Lake property lies within the northwestern portion of the Meen-Dempster greenstone belt, in the Uchi Lake Subprovince, near the northern margin of the Dobie Lake batholith. The belt consists of three volcanic cycles, each of which is dominated by massive to pillowed tholeiitic flows capped by intermediate-felsic pyroclastics. Stratigraphic tops are to the southwest and dips are generally vertical to slightly overturned to the south. Major deformation zones along the northern and southern boundaries of the Meen-Dempster belt have been interpreted as contact strain aureoles. Work suggests that the northern deformation zone that lies near the granite-greenstone boundary represents the southeastern end of a major fault zone (Bear Head Fault zone) which extends to the northwest for approximately 515 km to Lake Winnipeg and has a consistent dextral sense of movement. Along the northern contact, the main shear often lies within the Dobie batholith, however secondary shears transect the greenstone belt near the margin. Additionally, a system of conjugate shear bands occur with decreasing intensity and frequency away from the granite greenstone contact. The Golden Patricia Gold mine and the Dobie Lake Zone prospect are related to shear zones thought to be splays off the main shear/deformation zone to the north (AFRI 20000001401).

Lithology

Mineralization

Mineralization Comments

Dec 07, 2005 (B Nelson) - RESERVE CATEGORY: Drill Inferred, 301 000 tonnes at 5.5g/t Au.

Mar 10, 2015 (Therese Pettigrew) - Mineralization in the Dobie Zone is found between the deformed and altered amphibolite and the sheared felsic volcanics below. Mineralization is restricted to a variably sheared, locally silicified, biotitic alteration zone which contains at or near its base a narrow crack seal, greyish, cherty quartz vein. The quartz vein varies in width from 2 mm to 28 cm and is generally within 10 cm of the base of the alteration zone. Gold values range from <1g/t Au to 20 g/t Au (AFRI 20000002214).

Mineral Record Details

References

MonoMap - Geology of the Cat Lake-Pickle Lake area, districts of Kenora and Thunder Bay

Publication Number: R207 Date: 1982

Author: Sage R.P., Breaks F.W.

Publisher Name: Ontario Geological Survey

Location:

Map - Cat Lake-Pickle Lake, geological compilation series, Kenora and Thunder Bay districts

Publication Number: M2218 Scale: 1:253,440    Date: 1976

Author: Sage R.P., Breaks F.W., Troup W.R.

Publisher Name: Ontario Division of Mines

Location:

Mono - Mineral Deposits of the Central Portion of Uchi Subprovince, Volume 1, Meen Lake to Kesagiminnis Lake Portion

Publication Number: OFR5869 Page: 160-163  Date: 1993

Author: Seim G.Wm.

Publisher Name: Ontario Geological Survey

Location:

Map - Precambrian geology, Muskegsagagen-Bancroft lakes area, District of Kenora (Patricia Portion)

Publication Number: M2507 Scale: 1:50,000    Date: 1986

Author: Stott G.M., Wilson A.C.

Publisher Name: Ontario Geological Survey

Location:

Map - Geological series, Precambrian geology, Meen Lake area, eastern part, Kenora District (Patricia Portion)

Publication Number: P2620 Scale: 1:15,840    Date: 1983

Author: Stott G.M., LaRocque C.

Publisher Name: Ontario Geological Survey

Location:

Report an Error

We are continuously updating our assessment file / technical report information. If you notice errors in the data, please contact us.

Terms of Use

Please review our Terms of Use agreement for this data product.

Ministry Contact Information

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