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Baie Chapus Pyroxenite
Stratigraphic label: [narc]bcp
Map symbol: nAbcp
 

First published: 4 September 2019
Last modified:

 

 

 

  DISCLAIMER: This English version is translated from the original French. In case of any discrepancy, the French version shall prevail. 

Informal subdivision(s)
Numbering does not necessarily reflect the stratigraphic position.
 
None
 
Author(s): Goutier et al., 1996; Goutier et al., 1998
Age: Neoarchean
Stratotype: None
Type area: Chapus Bay area (NTS sheet 33F06), on the SW shore of the Robert-Bourassa Reservoir, James Bay
Geological province: Superior Province
Geological subdivision: La Grande Subprovince
Lithology: Pyroxenite, gabbro and peridotite
Category: Lithodemic
Rank: Lithodeme
Status: Formal
Use: Active

Background

This lithodem was introduced by Goutier et al. (1996) and Goutier et al. (1998) during the Ministère’s geological mapping work in the area of Yasinsky and Kowskatehkakmow lakes (sheets 33F05 and 33F06).

 

Description

The Baie Chapus Pyroxenite consits mainly of pyroxenite, plagioclase pyroxenite and olivine pyroxenite (Sappin et al., 2015). It also contains some metric to decametric layers and clusters of peridotite, dunite and gabbro. It is cut by gabbro and pyroxenite dykes (Sappin et al., 2015).

The main pyroxenite is dark green to bluish green and  medium to coarse grained. It is composed almost exclusively of clinopyroxene little altered (Goutier et al., 1996), including augite and, more sparsely, diopside (Sappin et al., 2015). Plagioclase is interstitial. In places, the rock has a pegmatitic texture with 5-70 cm clusters of plagioclase and centimetric pyroxene. Disseminated chalcopyrite (< 2%) is locally observed (e.g. outrcrop 1996-JG-1311). Goutier et al. (1996) found on outcrop 1996-JG-1331 a one-metre horizon of vanadium-bearing magnetite (see Baie Chapus mineralized zone and geochemical analysis 1996010443) of magmatic origin (Fe-Ti-V and Ni-Cu types; Cloutier, 2013). In addition, anomalous Au contents obtained in the eastern part of the intrusion (Dugas, 1997) may be consistent with gold-polymetal lode mineralization (Cloutier, 2013).

 

Thickness and distribution

The intrusion is oblong, with the main axis extending E-W for almost 3 km. The small axis is ~1 km long.

Dating

None.

Stratigraphic Relationship(s)

The Baie Chapus Pyroxenite intruded into tonalite of the Duncan Intrusions (nAdcn1).

Paleontology

Does not apply.

References

Publications available through SIGÉOM Examine

CLOUTIER, A., 2013. TECHNICAL REPORT ON THE RIVIERE AU CASTOR PROPERTY. ENTREPRISES MINIERES NOUVEAU-MONDE, rapport statutaire soumis au gouvernement du Québec; GM 67726, 69 pages.

DUGAS, M., 1997. RECONNAISSANCE GEOLOGIQUE (PROSPECTION ET CARTOGRAPHIE), PROPRIETE MENARIK-NORD. RESSOURCES MINIERES PRO-OR INC, rapport statutaire soumis au gouvernement du Québec; GM 56368, 56 pages, 3 plans.

GOUTIER, J., DOUCET, P., DION, C., DAVID, J. 1996. Géologie de la région du lac Yasinski (33F/05 et 33F/06), Baie-James.​ In VERS DE NOUVELLES DECOUVERTES. SEMINAIRE D’INFORMATION SUR LE RECHERCHE GEOLOGIQUE (PROGRAMME ET RESUMES 1996). MRN; DV 96-02, 48 pages.

GOUTIER, J., DOUCET, P., DION, C., BEAUSOLEIL, C., DAVID, J., PARENT, M., DION, D J., 1998. GEOLOGIE DE LA REGION DU LAC KOWSKATEHKAKMOW (33F/06). MRN; RG 98-16, 50 pages, 1 plan.

 

Other publications

SAPPIN, A.-A., HOULÉ, M. G., GOUTIER, J., MCNICOLL, V. 2015. Caractérisation pétrographique et géochimique de la Pyroxénite de Baie Chapus, Baie-James: Un exemple de minéralisation en Fe-Ti-V dans la Province du Supérieur. Commission géologique du Canada; Dossier public 7745, 1 feuille. https://doi.org/10.4095/295612

Suggested Citation

Ministère de l’Énergie et des Ressources naturelles (MERN). Baie Chapus Pyroxenite. Quebec Stratigraphic Lexicon. gq.mines.gouv.qc.ca/lexique-stratigraphique/province-du-superieur/pyroxenite-de-baie-chapus_en [accessed on Day Month Year].

Contributors

First publication

Jean Goutier, P. Geo., M.Sc. (redaction)

Mehdi A. Guemache, P. Geo., Ph.D. (coordination and critical review); Simon Auclair, P. Geo., M.Sc. (editing); Céline Dupuis, P. Geo., Ph.D. (English version); André Tremblay (HTML editing). 

 
6 juillet 2021