Geochemical Characterization, Geochronology, and Geodynamic Implications of Grenville Rare Earths Bearing Syenites, Haut-Saint-Maurice, QC, Canada

Abstract

Abstract:The syenites in the western part of the Grenville Province in Quebec have been known since the 1990s, but few studies have been carried out on them. Over the last three years, a mapping project carried out by the Ministère de l'Énergie et des Ressources naturelles has revealed the presence of several rare earth element (REE)-bearing syenitic intrusions in this area. In this paper, we present a geodynamic model for their formation based on geochemical, thermobarometric, and geochronological data. The intrusions were emplaced between 1038 +15/−13 Ma and 1009 ± 3 Ma. The syenites can be divided into two groups: (1) an older, REE-bearing group associated with a volcanic arc and (2) a younger group with lower REE contents associated with an anorogenic event. Formation temperatures were between 898 and 1005 • C, and pressures were between 2 and 10 kbar. This model involving two intrusive periods is in conflict with the model of a large, hot, long-duration collisional orogen proposed by Rivers et al. (2009) but is consistent with more recent studies.

Petro-Geochemistry, Genesis and Economic Aspect of Syenitic and Mafic Rocks in Mindif Complex, Far North Cameroon, Central Africa

“…Syenitic rocks are very good in mining and processing industries as they can host gemstones and ore minerals [9] [12] [13] [14] [15] [16], or can enrich soil profiles with some minable metallic elements [17]. They can also be mined as industrial mineral or raw material for some industries [18] [19] [20].…”