Geochemistry and petrogenesis of oligocene felsic volcanic rocks from the Pinos Volcanic Complex, Mesa Central, Mexico
Autor: | Krishia G. Acosta Fimbres, Sonia Alejandra Torres-Sánchez, Sanjeet K. Verma, José Ramón Torres Hernández, Héctor López-Loera, Darío Torres-Sánchez |
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Rok vydání: | 2020 |
Předmět: |
010506 paleontology
geography Felsic geography.geographical_feature_category Continental crust Partial melting Geochemistry Geology 010502 geochemistry & geophysics Sanidine 01 natural sciences Peralkaline rock Porphyritic Volcanic rock 0105 earth and related environmental sciences Earth-Surface Processes Petrogenesis |
Zdroj: | Journal of South American Earth Sciences. 102:102704 |
ISSN: | 0895-9811 |
Popis: | The Pinos Volcanic Complex (PVC) is located in the San Luis Potosi Volcanic Field (SLPV) and southern region of the Mesa Central that includes Oligocene rhyolites and trachydacites. These felsic volcanic rocks are characterized by porphyritic textures with a main mineralogical arrangement of phenocrystals of quartz, potassium feldspar (sanidine), plagioclase and biotite embedded in a vitreous matrix with microcrystals of quartz. They display peraluminous, high-silica, alkaline (not peralkaline) composition, with flat heavy rare earth element concentrations and negative Eu anomalies values. They are enriched in large-ion lithophile elements (LILEs; Rb, Ba, K, Th, Ce) relative to highfield-strength elements (HFSE; Nb, Zr, P, Ti). Trace element ratios trend highlights variable degree of partial melting rather than the role of fractional crystallization. The petrogenetic modelling of trace elements reveal that the felsic volcanic rocks are consistent with their formation via partial melting of the middle/upper continental crust. Multi-dimensional tectonic discriminant diagrams and magmatic model indicate an extensional tectonic environment for the genesis of the felsic volcanic rocks. |
Databáze: | OpenAIRE |
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