Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI000000002967

Record: MDI000000002967

General

Commodities

Primary Commodities: Graphite

Location

Township or Area: Miller, Matawatchan

Latitude: 45° 6' 57.53"    Longitude: -77° 4' 1.56"

UTM Zone: 18    Easting: 337410   Northing: 4997913    UTM Datum: NAD83

Resident Geologist District: Southern Ontario

NTS Grid: 31F03SE

Point Location Description: Precise, sample BM-18-11 location from OFR6356 p. 51

Location Method: Data Compilation

Exploration History

2015: geological mapping by the OGS identified several new graphite occurrences in the Centennial Lake area. 2016: prospectors J. Martin and J. Andreana located graphite mineralization and staked claims. 2017: J. Martin and J. Andreana carried out prospecting, sampling, and ground magnetic and resistivity surveys. 2018: J. Martin and J. Andreana carried out prospecting, staked additional claims, and conducted prospecting, Beep Mat and VLF–EM surveys in the central and southern parts of the property. A composite sample of graphitic schist from the central part of the property was submitted to Activation Laboratories, Ancaster, Ontario, for graphite liberation and flake size-quality testing.

Assessment Work on File

Geology

Province: Grenville

Terrane: Bancroft

Domain: Black Donald

Geology Comments

Mar 10, 2022 (Therese Pettigrew) - The following geological description is summarized from Duguet, Duparc and Mayer (2015), unless otherwise noted. The Black Mountain graphite prospect is located in the Centennial Lake area of the Black Donald domain in the northeastern part of the Central Metasedimentary Belt of the Grenville Province. The geology of the area is shown on a compilation map of the Denbigh area (Lumbers and Vertolli 2001) and on more recent field-based maps of the Black Donald Lake area (Duguet, Ma and Whitney 2017) and the Centennial Lake area (Duguet, Duparc and Mayer 2018). The geology of the Centennial Lake area is subdivided into 3 lithostructural units: the Western, Central, and Eastern units. The Black Mountain property lies within the Eastern unit, which is represented by a major, northeasterly trending synform centred on Centennial Lake. The lithological succession, from bottom to top, consists of migmatitic metapelitic rocks, amphibolites, calc-silicate schists and gneisses, and calcitic and dolomitic marbles. Dolomitic marbles in the Centennial Lake area are clean, white to grey, coarse grained and massive. They are in stratigraphic contact with siliciclastic units that include rusty schists that host graphite-pyrrhotite mineralization (Duguet, Duparc and Mayer 2018: unit 9g). In the Black Donald Lake area, Duguet, Whitney and Ma (2014) identified 2 continuous bands of siliciclastic rocks consisting of stromatic metatexite, calc-silicate rocks, and rusty schists containing pyrrhotite, pyrite and graphite. The bands are interpreted to belong to the same unit, repeated by folding. One band is exposed on the north shore of Black Donald Lake and the other, located along the south side of the lake, hosts the Black Donald graphite mine. The pyrrhotite-graphite–bearing units show up as coincident magnetic high and conductivity anomalies on airborne surveys conducted by Standard Graphite Corporation in the Black Donald Lake area (Desaulniers 2013). On the Renfrew aeromagnetic survey (Ontario Geological Survey 2014), the magnetic highs delineate the Centennial Lake synform and can be followed for over 30 km to the northeast. Duguet, Duparc and Mayer (2015) report 5 new graphite occurrences associated with sulphide-rich schists and gneisses in the Centennial Lake map area, all located on the edges of regional magnetic anomalies.

Lithology

Lithology Comments

Mar 10, 2022 (Therese Pettigrew) - The property straddles a central unit of migmatitic, felsic to intermediate gneiss that contains subunits of quartzite to quartzo-feldspathic gneiss and rusty schist. This unit coincides with a linear magnetic anomaly. Flanking, and locally interlayered with, the siliceous gneisses and schists are bands of carbonate metasedimentary rocks, predominantly calcitic marbles with narrow dolomitic lenses. Layering in the metasedimentary rocks, as observed in outcrops in the southern and central parts of the claim group, strikes 030° and dips vary from 70° west to 80° east. A cross section from east to west across one of the graphitic zones at the southern end of the property (graphite percentages are visual estimates only): • footwall: banded quartz-biotite and quartz-feldspar-biotite gneiss, minor garnet and trace pyrite • graphite zone: quartz-feldspar-biotite-phlogopite schist containing 1 to 3% fine- to medium-grained flake graphite; moderate to strong gossan on weathered surface; one 0.3 m-wide band containing 10% graphite and minor disseminated pyrite • hanging wall: quartz-feldspar-biotite gneiss, weathers grey, no visible sulphides or graphite Coarse-grained, white, calcitic marble was observed to the west of the felsic gneiss unit in the vicinity of Trapper Lake. The marble contains minor tremolite, phlogopite and a trace of graphite (Tessier et al., 2019).

Mineralization

Mineralization Comments

Mar 10, 2022 (Therese Pettigrew) - Samples collected in 2018 returned values of 1.67-3.47% graphite (Tessier et al., 2019).

Assay Samples

Mineral Record Details

Site Visit Information

Date: Jun 30, 2022

Geologist: Mateo Dorado-Troughton

Notes: Property was toured with the prospectors and the Southern Ontario RRG and DG. Access to the North zone was visited and representative samples and samples for assay were collected from the graphitic rusty schist and a dark, grey, siliceous, graphitic melanosome from the South zone.

References

Mono - Report of Activities 2018, Resident Geologist Program, Southern Ontario Regional Resident Geologist Report: Southeastern and Southwestern Ontario Districts and Petroleum Operations

Publication Number: OFR6356 Page: 48-58  Date: 2019

Author: Tessier A.C., LeBaron P.S., Smith A.C., Laidlaw D.A., Bousquet P., Fortner L.

Publisher Name: Ontario Geological Survey

Location:

Map - Precambrian Geology of the Centennial Lake Area, Grenville Province

Publication Number: P3807 Scale: 1:20,000    Date: 2018

Author: Duguet M., Duparc Q.

Publisher Name: Ontario Geological Survey

Location:

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For detailed information regarding this mineral record please contact the Southern Ontario Resident Geologist District Office