Boullé Complex
Stratigraphic label: [narc]bue
Map symbol: nAbue

First published: 20 October 2016
Last modified: 10 December 2020







  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): Charette et al., 2016
Age: Neoarchean
Stratotype: None
Type area: Jeannin Lake area (NTS sheet 24B)
Geological province: Churchill Province
Geological subdivision: Rachel-Laporte Lithotectonic Domain
Lithology: Porphyraceous monzonite and monzodiorite
Category: Lithodemic
Rank: Complex
Status: Formal
Use: Active




The Boullé Complex was introduced in the Jeannin Lake area (Charette et al., 2016) to group a package of porphyraceous intermediate intrusions circumscribed to a thrust sheet of the Rachel-Laporte Lithotectonic Domain; hence it is a structural complex.




The Boullé Complex consists of K-feldspar porphyritic intermediate intrusive rocks and syenogranite, all moderately magnetic and well foliated to protomylonitic. The different facies are generally observed together on outcrops and it was not possible to differentiate them at mapping scale 1:250 000.


Porphyraceous rock contains 15-20% microcline phenocrystals 0.5-2 cm long. Their composition varies from monzonite to quartz monzodiorite, including monzodiorite. Monzogranite is also locally observed. Intermediate rocks are partially recrystallized and dark grey with pink flecks in fresh exposure. They contain 25-35% ferromagnesian minerals including greenish brown biotite, locally chloritized, and hornblende. K-feldspar is also found in the matrix. Quartz is sparse (<3%) and plagioclase is variably sericitized. Myrmekitic textures are common and accessory minerals are relatively abundant. These include sphene, epidote, opaque minerals, apatite and allanite. Monzogranite is pale pink and contains up to 30% centimetric microcline phenocrystals and only 10% ferromagnesian minerals consisting of biotite.

Syenogranite is partially recrystallized, medium grained, very well foliated or lineated, and pink. It contains 3-7% greenish brown biotite, locally chloritized, which forms small millimetric to centimetric clusters. Quartz regularly forms small, discontinuous millimetric bands and exhibits undulatory extinction in thin sections. Muscovite and hematite are observed as accessory minerals. Centimetre to metre-wide layers or elongated enclaves of the porphyraceous facies are commonly observed in syenogranite.


Thickness and distribution

The Boullé Complex is located in the NW part of the Jeannin Lake area (Charette et al., 2016), where it forms a thrust sheet ~30 km long by 8 km wide elongated in a NW-SE direction within the Rachel-Laporte Lithotectonic Domain. It covers an estimated area of 149 km2.



An age of 2690 Ma was obtained in a monzonite of the Boullé Complex (outcrop 2015-MO-7075). Protoliths of gneiss or deformed intrusive rocks that form thrust sheets of the Rachel-Laporte Domain are all Archean (2668-2883 Ma; Lafrance and Vanier, 2021). These thrust sheets are interpreted as having overthrusted Paleoproterozoic rocks during the New Quebec Orogenesis (1.82-1.77 Ga; Machado et al., 1989).

Unit Sample Number Isotopic System Mineral Crystallization Age (Ma) (+) (-) Reference(s)
nAbue 2015-MO-7075A U-Pb Zircon 2690 4 4 Rayner et al., 2017



Stratigraphic Relationship(s)

The Boullé Complex consists of Archean rocks circumscribed to a thrust sheet from the Archean basement. This sheet is believed to have been emplaced within Paleoproterozoic volcano-sedimentary rocks of the Rachel-Laporte Lithotectonic Domain during the New Quebec Orogenesis. The Boullé Complex is therefore in fault contact with volcano-sedimentary rocks of the Laporte Supersuite.


Does not apply.


Publications available through SIGÉOM Examine

CHARETTE, B., LAFRANCE, I., MATHIEU, G., 2016. Géologie de la région du lac Jeannin, Québec, Canada. MERN; BG 2015-01, 1 plan.

DIMROTH, E., 1978. Région de la fosse du Labrador entre les latitudes 54° 30′ et 56° 30′. MRN; RG 193, 417 pages, 16 plans.

LAFRANCE, I., SIMARD, M., BANDYAYERA, D., 2014. GEOLOGIE DE LA REGION DU LAC SAFFRAY (SNRC 24F, 24G). MRN; RG 2014-02, 51 pages, 1 plan.

LAFRANCE, I., VANIER, M.-A. 2021. Domaine lithotectonique de Rachel-Laporte, sud-est de la Province de Churchill, Québec, Canada : synthèse de la géologie. MERN; BG 2021-01



Other publications

MACHADO, N., GOULET, N., GARIEPY, C. 1989. U-Pb geochronology of reactivated Archean basement and of Hudsonian Trough. Canadian Journal of Earth Sciences; volume 26, pages 1-15.

RAYNER, N.M., LAFRANCE, I., CORRIGAN, D., CHARETTE, B. 2017. New U-Pb zircon ages of plutonic rocks from the lac Jeannin area, Quebec: an evaluation of the Kuujjuaq domain and Rachel-Laporte zone. Geological Survey of Canada; Current Research 2017-4, 14 pages.



Suggested Citation

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



First publication

Isabelle Lafrance, P. Geo., M.Sc. (redaction)

Marie-Andrée Vézina, P. Geo. (coordination); Thomas Clark, P. Geo., Ph.D. and James Moorhead, P. Geo., M.Sc. (critical review); Claude Dion, Eng., M.Sc. (editing); Céline Dupuis, P. Geo., Ph.D. (English version); Jean-Marie Nzengue (HTML editing).

11 février 2020