Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI52P04NE00009

Record: MDI52P04NE00009

General

Commodities

Primary Commodities: Gold

Location

Township or Area: Achapi Lake Area

Latitude: 51° 9' 18.2"    Longitude: -89° 32' 52.18"

UTM Zone: 16    Easting: 321829.02   Northing: 5670154.24    UTM Datum: NAD83

Resident Geologist District: Thunder Bay North

NTS Grid: 52P04NE

Point Location Description: Transfer

Location Method: Conversion from MDI

Exploration History

1984-1989: Northern Dynasty Explorations and Ontario Gold Joint Venture carried out an exploration program consisting of geological mapping, airborne and ground geophysics, soil and rock geochemical sampling, diamond drilling and assaying. 1996-97: Northern Dynasty Minerals carried out additional geophysical surveys and re-assayed diamond drill core from the 1988-89 drilling program. 2007-08: Jiminex Inc. carried out prospecting and sampling. 2009: Jiminex conducted a helicopter-borne VTEM aeromagnetic survey. 2010-11: Jiminex conducted a mag survey, carried out prospecting and sampling, and drilled 9 DDH totalling 2869.08 m. 2012-13: Jiminex carried out geological mapping, prospecting, stripping, channel sampling, and drilled 3 DDH totalling 455.25 m.

Assessment Work on File

Geology

Province: Superior

Subprovince: Uchi

Terrane: North Caribou

Domain: Uchi

Belt: Lake St. Joseph

Geological Age: Neoarchean  

Geology Comments

Nov 09, 2006 (Mark Puumala) - The Ontario Gold Joint Venture Misehkow River gold prospect is located in a metavolcanic and metasedimentary belt described by Sage and Breaks (1982) as the Pashkokogan Lake-Misehkow River Belt. This belt is bounded to the north by Granitoid rocks of the Kagami Pluton and Seach-Achapi Lakes Granitoid Complex (Stott 1996), and to the south by the metasedimentary migmatites of the English River Subprovince. A large gabbro intrusion has been identified by Ho (1989) in the area to the north of the gold mineralized structure. However, the stratigraphy of the area immediately surrounding the mineralized structure is described by Ho (1989) as including a wide variety of lithologies including mafic to intermediate metavolcanics, felsic metavolcanics, clastic metasedimentary rocks, and banded iron formation. The mafic metavolcanics are indicated to be dominated by massive flows and fine-grained chlorite-carbonate schists, with local observations of pillow and hyaloclastite textures. Ho (1989) also mapped intermediate volcanic rocks that have been classified as flows and fragmental units. Outcrops of sericite-feldspar-quartz-carbonate schists have been tentatively classified as felsic volcanic tuff. Metasedimentary rock units that have been mapped by Ho (1989) in the area consist of intercalated clastic and chemical sediments. The clastic layers include greywacke, arenite and argillite, while the chemical sedimentary rocks consist of banded iron formation with variable amounts of magnetite and silica. Stott and Corfu (1991) have interpreted the boundary between rocks of the 2750-2730 Ma Confederation Assemblage and 2723-2713 Ma St. Joseph Assemblage to be located in close proximity to this occurrence, along an inferred contact that is approximately coincident with the course of the Misehkow River. Confederation Assemblage rocks are located to the north of the river, and are dominated by mafic metavolcanics, while the St. Joseph Assemblage rocks are located further to the south and include mafic and felsic metavolcanics and metasedimentary rocks. The Ontario Gold Joint Venture Misehkow River gold prospect is located in rocks interpreted to be part of the Confederation Assemblage. Ho (1989) has identified three generations of deformation in rocks in the vicinity of the Misehkow River gold prospect. The most prevalent structures are associated with what has been interpreted as the second (D2) deformation event. The D2 structures cross-cut an earlier D1 deformation fabric that has been identified in iron formation and include a schistosity that is well developed in all lithologies except the northern gabbro, and strikes between 235 and 250 with steep northerly dip. This S2 fabric is axial planar to isoclinal F2 folds whose axes are typically oriented 055/60. Discrete, anastamosing shear zones (< 1 m wide) having an approximate strike of 070 that are found within the iron formation have also been interpreted to be related to the D2 deformation event. A third phase of deformation (D3) has been inferred from the presence of a widely-spaced fracture cleavage oriented between 005 and 015. Kink bands observed in outcrop have also been interpreted as D3 structures. An approximately north-south-trending structure that parallels Smoking Jacket Creek and a cliff 300 m west of the identified zone of gold mineralization may represent a late D3 fault.

Lithology

Mineralization

Mineralization Comments

Apr 26, 2021 (R Tuomi) - Gold mineralization on the Misehkow claims is associated with pyrite and pyrrhotite occurrences in the siliceous iron formation and in sheared sulphide zones of the magnetite-rich gabbro intrusive to the north. Sulphide (mainly pyrite) occurrences in the siliceous iron formation are common and vary from 0.5% as disseminations to 10-20%. as shear controlled massive, coarse-grained bands. Gold concentrations are highest where sulphides are most abundant, with values up to 540 ppb gold in a grab sample (TM5-R-104) of 90% pyrite. Mineralized zones appear to be associated with variable amounts of silicification. Orientations of mineralized shear zones are variable, but predominantly trend NE-SW from 030 to 070 azimuth (Assessment report 52P04NE0511). DDH MIS-11-03 returned up to 18.3 g/t Au over 2.4 m, including 116 g/t Au over 0.3 m (Assessment 20000006705). DDH M-89-03 returned 3.21 ppm Au over 0.8 m at a depth of 80.6 m. DDH M-89-07 returned 3.3 g/t Au over 4.3 m at a depth of 58.1 m. DDH M-89-06 returned up to 2.0 g/t Au over 4.2 m at a depth of 108.8 m. DDH M-88-07 returned 0.16 oz/t Au (5.48 g/t Au) over 3.2 m from a depth of 213.4 m. DDH M-89-01 returned up to 0.208 oz/t Au (7.13 g/t Au) over 0.9 m.

Nov 09, 2006 (Mark Puumala) - Gold mineralization at the Ontario Gold Joint Venture Misehkow River gold prospect is hosted within an approximately east-northeast-striking deformation zone that cross-cuts metavolcanic and metasedimentary rocks (including iron formation). The rocks of this deformation zone are described as quartz-augen schist by Janes, Seim and Storey (1990), and contain up to 10% of 1 to 3 mm blue quartz augen in a matrix of quartz, iron-rich amphibole, and sericite schist. Gold mineralization primarily occurs in sulphidized iron formation (pyrrhotite and pyrite, with occasional arsenopyrite and chalcopyrite) that cross-cuts the deformation zone at an oblique angle (Ho 1989). Although zones of massive sulphide have been noted in the iron formation, the best gold assay results from this lithology are reported by Ho (1989) to have been obtained from sections with less than 2% sulphide. Although the altered and deformed iron formation appears to be the primary host for the gold mineralization, significant gold assay results have also been reported from samples of altered mafic volcanics. Janes, Seim and Storey (1990) indicate that the areas of significant gold mineralization also have a structural association with the hinge regions of macroscopic folds. The gold mineralized deformation zone is up to 120 m wide and has been mapped over a strike-length of approximately 3 km. The iron formation is completely enveloped by the deformation zone over a strike length of approximately 1000 m (Janes, Seim and Storey 1990). Alteration minerals that occur within the deformation zone include sericite, silica and iron carbonate. Anomalous gold mineralization has been reported in intersections from 13 diamond drill holes that have been drilled through the deformation zone over a strike length of approximately 2.1 km. The most significant assay results include 0.049 oz/t Au over 42.3 feet in ddh 88-05, 0.112 oz/t over 20.4 feet in ddh 88-07, and 0.393 oz/t over 2.3 feet in ddh 88-12. A number of diamond drill core samples from the 1988-89 exploration program were re-assayed in 1996, with the results generally being slightly lower (9.04% on average) than the original assays (Youngman 1998).

Mineral Record Details

References

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:

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:

Article - Sioux Lookout Resident Geologist's District - 1989

Publication Number: MP147.004 Page: 69-100  Date: 1997

Author: Janes D.A., Seim G.Wm., Storey C.C.

Publisher Name: Ontario Geological Survey

Location:

Mono - The Geology and Tectonic History of the Central Uchi Subprovince

Publication Number: OFR5952 Date: 1996

Author: Stott G.M.

Publisher Name: Ontario Geological Survey

Location:

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