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Nichicun Pluton
Stratigraphic label: [narc]nic
Map symbol: nAnic
 

First published: 13 December 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): Hammouche and Burniaux, 2018
Age: Neoarchean
Stratotype: None
Type area: Joubert Lake area (NTS sheet 23E03)
Geological province: Superior Province
Geological subdivision: La Grande Subprovince
Lithology: Megaporphyritic granite
Category: Lithodemic
Rank: Lithodeme
Status: Formal
Use: Active

Background

The Nichicun Pluton was introduced by Hammouche and Burniaux (2018) following 1:50 000 geological mapping work in the Joubert Lake area (sheets 33H01, 23E03 and 23E04), carried out during the summer of 2015. The pluton was initially assigned to the Lataignant Suite by Lamothe et al. (2000), during the 1:250 000 survey in the Nitchéquon Lake area. They relied on the composition a priori similar to the Dusterlo and Delmothe batholiths which are part of the Lataignant Suite. However, U-Pb dating of the Nichicun Pluton (David, 2018) indicates that it is much younger than the Lataignant Suite. On the other hand, the Artigny Pluton (Talla Takam et al., in preparation) has a crystallization age close to that of the Nichicun Pluton.

 

Description

The Nichicun Pluton consists of a megaporphyritic granite that contains up to 25% K-feldspar phenocrystals 1 to 7 cm long. The rock is massive (not foliated), homogeneous, pinkish in exposed surface and fresh exposure. Locally, there is an alignment of phenocrystals of magmatic origin. The rock consistently contains biotite (3-15%), hornblende (1-10%, locally up to 15%) and magnetite (2-4%). In places, isolated submillimetric garnet grains (1-2%) and trace sphene are observed.

The pluton contains numerous enclaves of paragneiss, metatexite and diatexite from the Rivière Salomon Formation. It is cut locally by pegmatitic granite.

 

Thickness and distribution

The Nichicun Pluton forms a mass ~180 km2 in the NE quarter of sheet 23E03. It extends 12 km N-S by 18 km E-W. No data are available to define its parameters in depth. The pluton is located NW of Nichicun Lake. In this area, two small intrusions with the same characteristics as the main intrusion were therefore assigned to this pluton.

Dating

Lamothe et al. (2000) attributed this intrusion to the Lataignant Suite aged between 2638 and 2642 Ma (David and Parent, 1997; Parent, 1998). Recent dating of the Nichicun Pluton indicates a crystallization age of 2592 ±5.2 Ma (David, 2018), much younger than intrusions of the Lataignant Suite. This age is comparable to that of the Artigny Pluton (2589 ±4 Ma; Davis and Sutcliffe, 2018).

Unit Sample Number Isotopic System Mineral Crystallization Age (Ma) (+) (-) Reference(s)
nAnic 1998-CB-3195A U-Pb Zircon 2592 5.2 5.2 David, 2019

Stratigraphic Relationship(s)

Contact of the Nichicun Pluton with adjacent units was not observed. However, its age suggests that it is intrusive into sedimentary rocks of the Rivière Salomon Formation. Moreover, it contains several enclaves from this formation.

Paleontology

Does not apply.

References

Publications available through SIGÉOM Examine

DAVID, J., 2018. Datation U-Pb dans la Province du Supérieur effectuées au GEOTOP en 2015-2016. MERN, GEOTOP; MB 2018-16, 24 pages.

DAVID, J., PARENT, M., 1997. GEOCHRONOLOGIE U-PB DU PROJET MOYEN-NORD. rapport statutaire soumis au gouvernement du Québec; GM 59903, 90 pages.

HAMMOUCHE, H., BURNIAUX, P., 2018. Géologie de la région du lac Joubert (SNRC 23E03, 23E04, 33H01), municipalité d’Eeyou Istchee Baie-James. MERN; RG 2018-04, 53 pages.

LAMOTHE, D., THERIAULT, R., LECLAIR, A., 2000. GEOLOGIE DE LA REGION DU LAC NITCHEQUON (23E). MRN; RG 99-14, 46 pages, 1 plan.

PARENT, M., 1998. GEOCHRONOLOGIE U-PB DU PROJET MOYEN-NORD, PHASE II. rapport statutaire soumis au gouvernement du Québec; GM 59904, 63 pages.

 

TALLA TAKAM, F., BEAUCHAMP, A.-M., MASSEI, F. In preparation. Géologie de la région du lac Emmanuel (33A09, 33A10, 33A15, 33A16) et du lac Léran (23D11, 23D12, 23D13, 23D14 et 23D15), Eeyou Istchee Baie-James, Québec. Ministère de l’Énergie et des Ressources naturelles, Québec.

 

Suggested Citation

Ministère de l’Énergie et des Ressources naturelles (MERN). Nichicun Pluton. Quebec Stratigraphic Lexicon. http://gq.mines.gouv.qc.ca/lexique-stratigraphique/province-du-superieur/pluton-de-nichicun_en [accessed on Day Month Year].

Contributors

First publication

Hanafi Hammouche, P. Geo., M.Sc. hanafi.hammouche@mern.gouv.qc.ca (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); Nathalie Bouchard (HTML editing).

 
12 mai 2021