DISCLAIMER: This English version is translated from the original French. In case of any discrepancy, the French version shall prevail.
Author: | Beauchamp, 2020 |
Age: | Neoarchean |
Stratotype: | None |
Type area: | Cadieux Lake area (NTS sheets 33A02, 33A07 and 33A08) |
Geological province: | Superior Province |
Geological subdivision: | Opinaca Subprovince |
Lithology: | Quartz monzodiorite, monzodiorite and diorite |
Category: | Lithodemic |
Rank: | Suite |
Status: | Formal |
Use: | Active |
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The Lépante Suite (nAlpn) was introduced by Beauchamp (2020) to describe intermediate intrusive rocks superimposed on an area of moderate magnetic susceptibility in the Eastmain-Sorbier Shear Zone, in the Cadieux Lake area.
Geochemical analyses of samples collected during summer 2018 mapping (Beauchamp, 2020) indicate that the Lépante Suite is a magnesian granitoid of alkaline-calcic to calc-alkaline affinity (Frost et al., 2001). It is generally metaluminous and type I (Maniar and Piccoli, 1989). In the diagram of Pearce et al. (1984), samples plot in the field of volcanic arc granites. The rare earth diagram normalized to CI chondrite (Palme and O’Neill, 2004) shows a slight light rare earth enrichment compared to heavy rare earths. Finally, negative anomalies in Nb, Ta, P and Ti, and positive in La, Ce and Nd are present on spider diagrams.
The Lépante Suite is located in the Cadieux Lake area (sheets 33A02, 33A07 and 33A08). The main intrusion is mostly longitudinal, 20 km long and 0.5 km to 3 km thick. Other small intrusive masses outcrop in the Eastmain-Sorbier Shear Zone.
None.
Rocks of the Lépante Suite cut paragneiss of the Laguiche Complex. At the macroscopic and microscopic scales, the Lépante Suite closely resembles rocks of the Macleod Batholith. It is possible that these two intrusive bodies are related and have similar ages.
Does not apply.
BEAUCHAMP, A.-M. 2020. Géologie de la région du lac Cadieux, sous-provinces d’Opatica et d’Opinaca, Eeyou Istchee Baie-James, Québec, Canada. MERN. BG 2019-02, 2 plans.
FROST, B.R., BARNES, C.G., COLLINS, W.J., ARCULUS, R.J., ELLIS, D.J., FROST, C.D. 2001. A geochemical classification for granitic rocks. Journal of Petrology; volume 12, numéro 11, pages 2033-2048. doi.org/10.1093/petrology/42.11.2033.
MANIAR, P.D., PICCOLI, P.M. 1989. Tectonic discrimination of granitoids. Geological Society of America Bulletin; volume 101, pages 635–643. doi.org/10.1130/0016-7606(1989)101<0635:TDOG>2.3.CO;2.
MCDONOUGH, W.F., SUN, S.S. 1995. The composition of the earth. Chemical Geology; volume 120, pages 223-253. doi.org/10.1016/0009-2541(94)00140-4.
PALME, H., O’NEILL, H.S.C. 2004. Cosmochemical estimates of mantle composition. In Treatise on Geochemistry. (Holland, H.D. and Turrekian, K.K. editors), Elsevier, Amsterdam, The Netherlands; volume 2, pages 1–38. doi.org/10.1016/B978-0-08-095975-7.00201-1.
PEARCE, J.A., HARRIS, N.B.H., TINDLE, A.G. 1984. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. Journal of Petrology; volume 25, pages 956–983. https://doi.org/10.1093/petrology/25.4.956.
Ministère de l’Énergie et des Ressources naturelles (MERN). Lépante Suite. Quebec Stratigraphic Lexicon. https://gq.mines.gouv.qc.ca/lexique-stratigraphique/province-du-superieur/intrusion-de-lepante_en [accessed on Day Month Year].
First publication |
Anne-Marie Beauchamp, Eng., M.Sc. anne-marie.beauchamp@mern.gouv.qc.ca (redaction) Mehdi A. Guemache, P. Geo., Ph.D. (coordination); Patrice Roy, P. Geo., M.Sc. (critical review); Simon Auclair, P. Geo., M.Sc. (editing); Ricardo Escobar Moran (HTML editing); Céline Dupuis, P. Geo., Ph.D. (English version). |