(A) Map of the Trans-Mexican Volcanic Belt (TMVB) along with the plate tectonic setting of southern Mexico (modified after Verma, 2015), showing the MGVF area (red square box). In addition, mafic and intermediate magmas display a chemical diversity which is related to mantle heterogeneity domains in the mantle wedge.įIGURE 1. In contrast, intermediate magmas where divided into two main groups based on the Mg content: high-Mg intermediate rocks, which seems to be derived from different rates of assimilation and fractional crystallization process, and low-Mg intermediate rocks, which can be related to fractional crystallization of mafic magmas. We propose that MGVF mafic magmas are derived from low degrees (∼1–15%) of partial melting of a spinel-bearing lherzolite source/mantle related to the rapid ascent of the asthenosphere caused by an extensional regime that is present in the area.
Conventional procedures and statistical techniques were used to process the dataset. We used data published for 429 samples of mafic and intermediate volcanic rocks. Here, we compile geological and geochemical data of the MGVF to discuss the petrogenesis of mafic magmas along the volcanic field and the role they play in the generation of intermediate melts. Nevertheless, the origin and evolution of the mafic components and their relation with the intermediate rocks have been poorly discussed. The MGVF has been studied for decades, focusing in its dominant intermediate magmas. Although these processes are linked to the subduction of the Cocos plate beneath the North American plate, the magmatic plumbing system of the MGVF remains not completely understood. It is essential to understand the geochemical evolution of its products, the complex petrogenetic processes, and the origin of magmas in central Mexico. Its eruptive activity goes back to 7 Ma, it is considered an active volcanic field, and the composition of its rocks varies from mafic to silicic. The Michoacán–Guanajuato volcanic field (MGVF) in the western Trans-Mexican Volcanic Belt is one of the largest and most diverse monogenetic volcanic fields in the world holding more than 1200 volcanic vents. 2Institute of Geophysics and Planetology, University of Hawai, Honolulu, HI, United States.1Instituto de Geofísica, Unidad Michoacán, Universidad Nacional Autónoma de México, Morelia, Michoacán, México.Darío Torres-Sánchez 1*, Giovanni Sosa-Ceballos 1, Xavier Bolós 2 and José Luis Macías 1
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