DISCLAIMER: This English version is translated from the original French. In case of any discrepancy, the French version shall prevail.
|Stratotype:||Type section of Member B of the Péribonca Formation (now Péribonca Group) of Chown and Caty (1973). The section, oriented E-W, begins on the east bank of a small lake (52º17’N, 70º42’W) and ascends the western slope of the main range of the Otish Mountains.|
|Type area:||Plateau of the Marie-Victorin Mountains, in the Frappe-à-Bord Lake area (SE corner of sheet 23D07)|
|Geological province:||Superior Province|
|Geological subdivision:||Opatica Subprovince|
|Lithology:||Dolomitic sandstone, polymictic conglomerate|
The “Marie-Victorin Formation” was established by Genest (1989). This name refers to the Marie-Victorin Mountains, an area forming a plateau where the unit mainly outcrops (sheet 23D07). The Marie-Victorin Formation corresponds to the summit of Member B of the Péribonca Formation (Chown and Caty, 1973), later elevated to group status (Péribonca Group) by Genest (1989). Correlations between the different nomenclature used in previous work is summarized in the Otish Supergroup record and in the summary table of Genest (1989, p. 21). The Minstère’s compilation maps (MRNF, 2010) are essentially based on descriptions from Genest (1989) which are presented in the following section.
The Marie-Victorin Formation consists of conglomerate and arkosic sandstone. Genest (1989) subdivided the formation into two distinct members, namely conglomeratic (Member A) and sandy (Member B) sequences. This nomenclature is not used here.
Granule and pebble conglomerate at the base of the unit is a uniform deposit, usually forming sorted sequences. It is composed of subrounded quartz and granitoid pebbles <2.5 cm and mudstone fragments <7 cm, derived from the underlying Gaschet Formation. Conglomerate is overlain by red, highly hematitized arkosic sandstone with a siliceous matrix. This well-sorted sandstone is composed of well-rounded grains coated with hematite. Feldspar grains are whitish in altered surface and have an orange shade in fresh exposure.
The stratotype of the Marie-Victorin Formation is described in the type section of Member B of the Péribonca Formation (now Péribonca Group) of Chown and Caty (1973). This E-W oriented section begins on the east shore of a small lake and ascends the western slope of the main range of the Otish Mountains:
The Marie-Victorin Formation is located in the centre of a regional syncline in the form of a narrow strip of approximately 25 km by 2.5 km, generally oriented NE-SW, in the NE portion of the Péribonca Group. The unit has a maximum thickness of 146 m and is limited to the top by an erosional surface. Conglomerate has a maximum thickness of 26 m, while sandstone reaches 120 m in the Frappe-à-Bord Lake area (sheet 23D07).
The Marie-Victorin Formation unconformably overlies the Gaschet Formation and is covered with quaternary deposits.
Does not apply.
MRNF. 2010. CARTE(S) GÉOLOGIQUE(S) DU SIGEOM – feuillet 23D. CG SIGEOM23D, 16 plans.
Chown, E.H., Caty, J.L. 1973. Stratigraphy, petrography and paleocurrent analysis of the Aphebian clastic formations of the Mistassini-Otish Basin. In Huronian stratigraphy and sedimentation. Edited by G.M. Young. Geological Association of Canada; Special Paper 12, pages 49-71.
Genest, S. 1989. Histoire géologique du Bassin d’Otish, protérozoïque inférieur (Québec). Université de Montréal, doctoral thesis, 334 pages.
Ministère de l’Énergie et des Ressources naturelles (MERN). Marie-Victorin Formation. Quebec Stratigraphic Lexicon. http://gq.mines.gouv.qc.ca/lexique-stratigraphique/province-du-superieur/formation-de-marie-victorin_en [accessed on Day Month Year].
Céline Dupuis, P. Geo., Ph.D. céline.firstname.lastname@example.org (redaction)
Mehdi A. Guemache, P. Geo., Ph.D. (coordination); Claude Dion, Eng., M.Sc. (critical review and editing); Céline Dupuis, P. Geo., Ph.D. (English version); Yan Carette (HTML editing).