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Atshakash Complex
Stratigraphic label: [ppro]ats
Map symbol: pPats

 

ABANDONED UNIT

Publication: 2 August 2018

 

 

  DISCLAIMER: This English version is translated from the original French. In case of any discrepancy, the French version shall prevail. 

Author: Van der Leeden, 1994, 1995
Age: Paleoproterozoic
Stratotype: None
Type area: Mistinibi Lake area (NTS sheets 23P15 and 23P16)
Geological province: Churchill Province
Geological subdivision: George Lithotectonic Domain
Lithology: Volcano-sedimentary rocks
Category: Lithodemic
Rank: Complex
Status: Formal
Use: Abandoned
Replacement Unit(s)
Table of contents
 
 

 

 

 

Background

The Atshakash Complex was informally named by van der Leeden (1994, 1995) in the Hutte Sauvage Lake and Mistinibi Lake areas. Danis (1991) and Owen (1989) also used the term “Atshakash Schists” in the Raude Lake and Leif Lake areas, respectively. A regional compilation by Ministère’s geologists in 2003 formalized the use of the term Atshakash Complex and divided it into 7 units: marble and calcosilicate rocks (pPats1); arkosic metasandstone (pPats2); metamorphosed ultramafic rocks (pPats3); amphibolite (pPats4); felsic volcaniclastics, augen schists (pPats5); quartzitic meta-arenite and metasubarkose (pPats6); biotite-muscovite schist, graphite schist and quartzofeldspathic rocks (pPats7).

This unit was abandoned by Charette et al. (2018) following field investigationss in the summer of 2016 as part of the Southeastern Churchill Province (SECP) regional synthesis (Lafrance et al., 2018).

Reasons for abandonment

Geological mapping conducted by the Ministère in the summer of 2016 revealed that rocks of the Atshakash Complex were similar to those of the Tunulic Complex. Hence they were grouped together in the same unit, the Tunulic Complex.

References

Author(s) Title Year of Publication Hyperlink (EXAMINE or Other)

CHARETTE, B. – LAFRANCE, I. – VANIER, M.A.

Domaine de George, sud-est de la Province de Churchill, Nunavik, Québec, Canada : synthèse de la géologie. Bulletin GéologiQUE, Ministère de l’Énergie et des Ressources naturelles. 2018 BG 2018-11
DANIS, D. Géologie de la région du lac Raude, territoire du Nouveau-Québec. Ministère des Ressources naturelles, Québec; ET 88-10, 63 pages, 5 cartes. 1991 ET 88-10
LAFRANCE, I. – CHARETTE, B. – VANIER, M.A. Sud-est de la Province de Churchill, Nunavik, Québec, Canada : synthèse de la géologie. Ministère de l’Énergie et des Ressources naturelles, Québec. 2018 Bulletin géologiQUE
OWEN, J.V. Géologie de la région du lac Leif, territoire du Nouveau-Québec. Ministère des Ressources naturelles, Québec; ET 87-18, 48 pages, 3 plans. 1989 ET 87-18
VAN DER LEEDEN, J. Géologie de la région du lac Mistinibi, territoire du Nouveau-Québec. Ministère des Ressources naturelles, Québec; MB 95-45, 111 pages, 3 plans. 1995 MB 95-45
VAN DER LEEDEN, J. Géologie de la région du lac de la Hutte Sauvage, territoire du Nouveau-Québec. Ministère des Ressources naturelles, Québec; MB 94-32, 101 pages, 2 plans. 1994 MB 94-32

 

 

10 février 2020