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 |
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).
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.