Petrogenetic characterization of La Vasca alkaline complex and its relationship to the Eastern Mexican Alkaline Province
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Date
2025
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier Ltd
Abstract
Peralkaline and agpaitic igneous rocks with local eudialyte mineralization have been reported in the La Vasca
alkaline complex (LVAC) but no detailed information on its age and relationship to the Eastern Mexican Alkaline
Province (EMAP) has been available. We present petrological, geochemical, isotopic, and geochronological data
from the LVAC and the surroundings, located in northwestern Coahuila. The main intrusion is composed of
ferroan granitoids that are classified by their alumina saturation index into metaluminous and peralkaline. The
metaluminous rocks are monzonite and syenite with post-collisional geochemical affinity. Middle Eocene zircon
ages of these rocks range between 47.6 ± 0.3 Ma and 45.4 ± 0.3 Ma and are significantly older than other
alkaline rocks from the EMAP. The peralkaline rocks are composed of syenite and eudialyte-bearing foid-syenite
with intraplate geochemical affinity that probably coevolved with the metaluminous rocks. Both groups show
minimal crustal contamination, with affinity to an Ocean Island Basalt mantle source. The LVAC is explained by a
similar formation model than other rocks of the EMAP, suggesting its extension into northwestern Coahuila.
Furthermore, the eudialyte foid-syenites represent the first occurrence of agpaitic rocks in Mexico
Description
Keywords
Peralkaline, Magmatism, Agpaitic rocks, Geochronology, La Vasca
Citation
Martínez-Salinas, E. A. et al. (2025) Petrogenetic characterization of La Vasca alkaline complex and its relationship to the Eastern Mexican Alkaline Province. Journal of South American earth sciences. [Online] 164.