Merville Pluton
Stratigraphic label: [ppro]mer
Map symbol: pPmer

First published: 20 September 2018
Last modified:








Translation of original French




Informal subdivision(s)
Numbering does not necessarily reflect the stratigraphic position.
Author: Hammouche et al., 2011
Age: Paleoproterozoic
Stratotype: None
Type area: Merville Lake area (NTS sheet 23P02)
Geological province: Churchill Province
Geological subdivision: George Lithotectonic Domain
Lithology: Diorite
Category: Lithodemic
Rank: Lithodeme
Status: Formal
Use: Active




The Merville Pluton was defined by Hammouche et al. (2011) to limit three massive diorite intrusions in the west-central portion of the Merville Lake area (sheet 23P02). Given its characteristics similar to the De Pas Granitic Suite diorite, the Merville Pluton was considered to be part of the latter, as part of the synthesis of the Southeastern Churchill Province (SECP; Lafrance et al., 2018). It takes its name from Merville Lake, on the shore of which it was observed.





The Merville Pluton consists mainly of diorite and lesser proportions of hypersthene diorite, monzonite and mangerite. These rocks are massive, non-foliated, medium grained, and greyish to greenish grey in fresh exposure. In thin section, diorite is rich in plagioclase, with some quartz (<5%) locally as myrmekite, microcline (5%), biotite (10%) and hornblende (10%). Magnetite (1-3%) and sphene (<1%) are consistently present. Plagioclase is slightly sericitized and some initial alteration is noticeable on biotite and hornblende.


Locally, decimetric to metric intrusions of medium to coarse-grained pink granite containing magnetite and epidote plating cut diorite and hypersthene diorite.



Thickness and Distribution

The Merville Pluton occurs as three distinct masses in the southern part of the George Lithotectonic Domain (Charette et al., 2018), specifically in the west-central portion of sheet 23P02. The main mass (~5 km in diameter) is circular and has a high magnetic signature. The unit covers a limited total area of ~28 km2.



Stratigraphic Relationship(s)

The Merville Pluton represents a late phase of the De Pas Granitic Suite since rocks are not deformed and cut other De Pas units, which cut each other.


Does not apply.


Author(s) Title Year of Publication Hyperlink (EXAMINE or Other)
CHARETTE, B. – LAFRANCE, I. – VANIER, M.-A. George Lithotectonic Domain, Southeastern Churchill Province, Nunavik, Quebec, Canada: Geological Synthesis. Ministère de l’Énergie et des Ressources naturelles, Québec. BG 2018-11. 2018 BG 2018-11
HAMMOUCHE, H. – LEGOUIX, C. – GOUTIER, J. – DION, C. – PETRELLA, L. Géologie de la région du lac Bonaventure. Ministère des Ressources naturelles et de la Faune, Québec; RG 2011-03, 37 pages, 1 plan. 2011 RG 2011-03
LAFRANCE, I. – CHARETTE, B. – VANIER, M.-A. Southeastern Churchill Province, Nunavik, Quebec, Canada: Geological Synthesis. Ministère de l’Énergie et des Ressources naturelles, Québec. Preliminary BG. 2018 Bulletin géologiQUE
17 août 2020