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Poudingue dykes
Stratigraphic label: [prot]pou
Map symbol: Ppou

First published: 6 March 2018
Last modified:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Translation of original French

Informal subdivision(s)
Numbering does not necessarily reflect the stratigraphic position.
 
None
 
Author:Charbonneau et al., 1991
Age:Proterozoic
Reference section: 
Type area:NW of Chapais, NTS sheets 32G14-200-0201 and 32 J03-200-0102
Geological province:Superior Province
Geological subdivision:Abitibi and Opatica subprovinces
Lithology:Diabase
Type:Lithodemic
Rank:Lithodeme
Status:Informal
Use:Active

Background

The Poudingue dyke was initially recognized by MacIntosh (1977) and informally named by Charbonneau et al. (1991). Since then, other dykes with the same orientation and located in the same area have been assigned to this swarm (Leclerc and Daoudene, in preparation).

Description

The Poudingue dykes consist of medium-grained gabbro that form linear hills resistant to erosion. Thin-section samples of MacIntosh (1977, p. 86) are composed of 50% clinopyroxene, 40% labradorite, 5 to 10% opaque minerals, 1% leucoxene, 5% amphibole, and 1 to 5% quartz. Plagioclase is saussuritized and clinopyroxene is chloritized and amphibolized. 

Thickness and distribution

The Poudingue dykes correspond to positive NNW-SSE oriented magnetic anomalies on a total residual magnetic field map (Keating and d’Amours, 2010). The thickness is estimated at 100 m (Charbonneau et al., 1991).

Dating

None. 

Stratigraphic Relationship(s)

The Poudingue dykes cut volcano-sedimentary rocks of the Roy and Opémisca groups. They also cut the Eau Noire, Moraine, Deux Granites and Guettard stocks, as well as the Abitibi Dykes. It would therefore be the youngest dykes identified in the area northwest of Chapais. 

Paleontology

Does not apply.

References

Author(s)TitleYear of PublicationHyperlink (EXAMINE or Other)
CHARBONNEAU, J.-M. – PICARD, C. – DUPUIS-HÉBERT, L.Synthèse géologique de la région de Chapais-Branssat (Abitibi). Ministère de l’Énergie et des Ressources, Québec; MM 88-01, 200 pages, 13 maps.1991MM 88-01
KEATING, P. – D’AMOURS, I.Réédition des données numériques en format Géosoft (profils) des levés aéroportés de l’Abitibi, au Québec. Ministère des Ressources naturelles et de la Faune, Québec; DP 2010-09, 6 pages.2010DP 2010-09
LECLERC, F. – DAOUDENE, Y.Levé géologique dans la Sous-province de l’Abitibi à l’ouest de Chapais (région du lac des Deux Orignaux). Ministère de l’Énergie et des Ressources naturelles, Québec.In preparationBulletin géologiQUE
MACINTOSH, J.A.Geology of the Lantagnac – La Touche (comté d’Abitibi-Est). Ministère des Richesses naturelles, Québec; DPV 497, 131 pages, 1 map.
 
1977DPV 497

 

 

 

16 janvier 2019