Grandroy Stock
Stratigraphic label: [narc]ggr
Map symbol: nAggr

First published: 5 February 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.
Author(s): Graham, 1952
Age: Neoarchean
Stratotype: None
Type area: Area north of Hématite Bay, in QTS sheet 32G16-200-0202.
Geological province: Superior Province
Geological subdivision: Abitibi Subprovince
Lithology: Granodiorite
Category: Lithodemic
Rank: Lithodeme
Status: Formal
Use: Active


The first description of the Grandroy Stock was given by Graham (1952).



The intrusion consists of coarse-grained grey granodiorite in fresh exposure. Fracturing the rock results in alteration to chlorite, epidote and hematite giving the rock a beige to pink patina.


Thickness and distribution

The Grandroy Stock outcrops primarily on the shores of Hématite Bay (Chibougamau Lake), but some outcrops attributed to this stock have also been identified south of Bear Bay. The northern limit of the Grandroy Stock is marked by the Grondines Shear Zone.



Stratigraphic Relationship(s)

North of Hématite Bay, the Grandroy Stock cuts mafic volcanic rocks of the David Member, volcanoclastic rocks of the Allard Member (2726.7 ±0.7 Ma; Leclerc et al., 2011) and mafic volcanic rocks of the Bruneau Formation (2724.4 ±1.2 Ma; Davis et al., 2014). West of Mount Sorcier, following Bear Bay, the Grandroy Stock cuts rocks of the Lac Doré Intrusive Suite anorthositic zone (2728.3 +1.2/-1.1 to 2727.0 ±1.3 Ma; Mortensen, 1993).


Does not apply.


Publications available through SIGÉOM Examine

DAVIS, D.W., SIMARD, M., HAMMOUCHE, H., BANDYAYERA, D., GOUTIER, J., PILOTE, P., LECLERC, F., DION, C., 2014. Datations U-Pb effectuées dans les provinces du Supérieur et de Churchill en 2011-2012. MERN, GEOCHRONOLOGICAL LABORATORY; RP 2014-05, 62 pages.





Other publications



LECLERC, F., BÉDARD, J.H., HARRIS, L.B., McNICOLL, V., GOULET, N., ROY, P., HOULE, P. 2011. Tholeiitic to calc-alkaline cyclic volcanism in the Roy Group, Chibougamau area, Abitibi Greenstone Belt – Revised stratigraphy and implications for VHMS exploration. Canadian Journal of Earth Sciences; volume 48, pages 661-694.

MORTENSEN, J.K. 1993. U-Pb geochronology of the eastern Abitibi subprovince. Part 1 : Chibougamau – Matagami – Joutel region. Canadian Journal of Earth Sciences; volume 30, pages 11-28.

Suggested Citation

Ministère de l’Énergie et des Ressources naturelles (MERN). Grandroy Stock. Quebec Stratigraphic Lexicon. [accessed on Day Month Year].


First publication

François Leclerc, P. Geo., Ph.D. franç  (redaction)

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

5 juillet 2021