Magmas heterogéneos del campo volcánico Cuaternario de la Sierra de Chichinautzin (México central): el papel de un manto con anfibol y los procesos de evolución magmática

The Quaternary Sierra Chichinautzin volcanic field (SCVF) is located at the volcanic front of the Trans–Mexican Volcanic Belt (TMVB), 350 km from the Middle American trench where the Cocos plate subducts beneath the North American plate. The SCVF is characterized by more than 200 monogenetic centers, ranging in composition from rare basalts to dacites. Less evolved terms have aphyric to porphyritic textures with phenocrysts of euhedral olivine (± Cr–spinels inclusions) + cpx, –whereas evolved terms have porphyritic textures with phenocrysts of pyroxene (cpx>opx), xenocrysts of corroded quartz, and sieve–textured plagioclase from the local basement. Regardless of the degree of magmatic evolution, plagioclase occurs as microphenocrysts or in the groundmass.