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Kaupanaukau Suite
Stratigraphic label: [narc]kup
Map symbol: nAkup

First published: 31 May 2018
Last modified:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Translation of original French

 

 

Informal subdivision(s)
Numbering does not necessarily reflect the stratigraphic position.
 
nAkup3 Pink granitic pegmatite
nAkup2 Pink granitic pegmatite and granite
nAkup1 Pink biotite ± magnetite granite
 
Author:Bandyayera and Daoudene, 2018
Age:Neoarchean
Reference section: 
Type area:La Sicotière Lake area (NTS sheet 32N08)
Geological province:Superior Province
Geological subdivision:Nemiscau and La Grande subprovinces
Lithology:Intrusive granitic rocks
Type:Lithodemic
Rank:Suite
Status:Formal
Use:Active

 

 

Background

The granitic rocks of the Kaupanaukau Suite were part of the Champion Complex, a large polyphase intrusive mass located south of the Eastmain Group, and constituted the southern extension of the La Grande Subprovince (Card and Ciesielski, 1986). The name “Kaupanaukau Suite” was introduced by Bandyayera and Daoudene (2018) following the summer 2017 mapping campaign. This suite includes all of the late granitic rocks in the Champion Lake area that belong to the La Grande and Nemiscau subprovinces (Bandyayera and Daoudene, 2016; Bandyayera and Daoudene, in preparation).

Description

The Kaupanaukau Suite consists of a package of granitic intrusions and granitic pegmatite that cut all the other Archean rocks in the region. It consists of three units: a pink biotite ± magnetite granite unit (nAkup1), a pink pegmatite and granite unit (nAkup2) and a pink granitic pegmatite unit (nAkup3). 

 

Kaupanaukau Suite 1 (nAkup1): Pink Biotite ± Magnetite Granite

The nAkup1 unit occurs as decametric to kilometric intrusions in the Rupert Complex and the Champion Complex. It consists of massive biotite ± magnetite granite, homogeneous, heterogranular and low to highly magnetic. In places, the rock has a granodioritic composition. The nAkup1 unit is very poor in ferromagnesian minerals (<5%) and contains no garnet. The principal minerals are quartz, plagioclase, partially chloritized biotite (<5%) and magnetite (1-8%). Accessory apatite and zircon are observed in thin section.

Geochemically, these granite intrusions are typically peraluminous, type I and syncollisional. 

 

Kaupanaukau Suite 2 (nAkup2): Pink Granitic Pegmatite and Granite

The nAkup2 unit consists of a package of granitic pegmatite (Akup3 unit) and biotite ± magnetite granite, which are non-mappable separately at a 1:50,000 scale. Grain size contacts are generally gradual and diffuse, from medium and coarse-grained to pegmatitic, and locally sharp, showing intrusion of pegmatite into granite. 

 

Kaupanaukau Suite 3 (nAkup3): Pink Granitic Pegmatite

The nAkup3 unit consists of pale pink granitic pegmatite with a graphic structure. The rock is magnetic and has a massive and heterogranular appearance, as well as locally visible bedding or pegmatitic zoning. It regularly contains centimetric clusters of K-feldspar (up to 5 cm) cemented by quartz. Pegmatite has well-developed graphic and perthitic textures. Granitic pegmatite is also distinguished by a low content of ferromagnesian minerals representing less than 5% of the rock. The rock contains no garnet and rarely tourmaline. The nAkup3 unit contains enclaves of all other units of the Champion Complex. South-east of the Nemiscau Lake region (sheet 32N07), between the Rupert River and Nemiscau Lake, a kilometric pink pegmatite intrusion assigned to the nAkup3 unit contains up to 20% of paragneiss-derived migmatite enclaves originating from the surrounding supracrustal rocks of the Rupert Complex. 

Thickness and distribution

The various units in the Kaupanaukau Suite are elongated and are up to 15 km long and 2 km wide. In places, they form small rounded masses ranging from 1.5 to 2 km in diameter. 

Dating

None.

Stratigraphic Relationship(s)

The Kaupanaukau Suite cuts all the other Archean rocks in the Champion Lake area, including the Champion Complex, the Lac des Montagnes Group and the Rupert Complex. 

Paleontology

Does not apply.

References

Author(s)TitleYear of PublicationHyperlink (EXAMINE or Other)
BANDYAYERA, D. DAOUDENE, Y.Géologie de la région du lac Nemiscau, secteur ouest de la rivière Rupert (SNRC 3206, 32N07 et 32N11). Ministère de l’Énergie et des Ressources naturelles, Québec; CG-2016-02, 1 carte.2016CG 2016-02
BANDYAYERA, D. DAOUDENE, Y.Géologie de la région du lac Champion, sous-provinces de La Grande et de Nemiscau, à l’est de Waskaganish, Municipalité Eeyou Istchee Baie-James, Québec, Canada. Ministère de l’Énergie et des Ressources naturelles, Québec2018Bulletin géologiGUE
CARD, K.D. – CIESIELSKI, A.DNAG N°1 Subdivisions of the Superior Province of the Canadian Shield. Geosciences Canada; volume 13, pages 5-13.1986Source

 

8 novembre 2018