|Author:||Bandyayera and Daoudene, 2018|
|Type area:||La Sicotière Lake area (NTS sheet 32N08)|
|Geological province:||Superior Province|
|Geological subdivision:||Nemiscau Subprovince|
|Lithology:||Foliated biotite granite|
Table des matières
The Canards Suite is a lithodeme introduced to describe a series of generally foliated granitic intrusions into the more or less migmatized metasedimentary sequence of the Rupert Complex (Bandyayera and Daoudene, 2018). These intrusions were previously associated with granitic units of the Champion Complex. However, recent geochemical and petrographic data (Bandyayera and Daoudene, 2018) show that granites of the Champion Complex are generally massive and have a composition similar to that of syn-collisional granites (Pearce et al., 1984), while granites of the Canards Suite are typically deformed and associated with a volcanic arc environment (Pearce et al., 1984).
The Canards Suite (nAcnd) includes a series of granitic intrusions located to the northeast of the La Sicotière Lake area (NTS sheet 32N08) and to the southeast of the Champion Lake area (sheet 32N09). It is associated with a positive magnetic anomaly, oriented EW, that continues eastward in the Montagnes (sheet 32O12) and Béchard (sheet 32O05) lakes area. The main intrusion is more than 25 km long and 7 km wide.
Unit nAcnd consists mainly of biotite granite, medium to coarse-grained, locally pegmatitic, homogeneous and slightly to moderately magnetic. Granite is light white pink in altered surface, light medium pink in fresh exposure and, in places, reddish due to hematization. The rock is typically deformed, foliated, locally gneissic. Intense deformation is defined by stretching and alignment of quartz grains or rods in the preferential direction of foliation. Biotite schlierens have also been reoriented parallel to foliation. The homogeneous rock contains 3-10% biotite (locally up to 15%) and 1-3% magnetite. Magnetite is highly disseminated and locally forms centimetric clusters.
In places, some outcrops contain up to 10% granitic pegmatite clusters. Unit nAcnd also contains metric biotite-hornblende tonalite enclaves, foliated to gneissic, stretched parallel to foliation planes. There are also up to 10% metric enclaves of brownish paragneiss in altered surface and medium grey in fresh exposure.
Geochemically, granitic rocks of the nAcnd unit are type I, peraluminous, of calc-alkaline calcic affinity, moderately to strongly enriched in potassium, characterized by negative europium anomalies, and formed in an environment similar to that of volcanic arcs (Pearce et al., 1984).
The Canards Suite is composed of long, diiscontinuous hectommetric to kilometric intrusions that cut the Rupert Complex. New geophysical (D’Amours, 2011) and geological data (Bandyayera and Daoudene, 2018) show that it extends east-west, at least 25 km long and 7 km wide.
In the Champion and La Sicotière lakes region, the Canards Suite marks the southern limit of the Lac des Montagnes Group volcano-sedimentary units separated by the Poste Albanel Shear Zone. It also cuts the gneissic tonalite, granodiorite and diorite units of the Champion Complex, interpreted as the bedrock upon which metasedimentary units of the Rupert Complex have been deposited.
Does not apply.