Magmatic Evolution, Aeromagnetic Structure, and Geological Framework of the Mascota Volcanic Field, Central Jalisco Block, Western Mexico

The Mascota Volcanic Field (MVF), located near the structural center of the Jalisco Block in western Mexico, represents one of the youngest and most compositionally diverse volcanic provinces of the Trans-Mexican Volcanic Belt (TMVB). Its evolution reflects the interplay between arc magmatism, transtensional tectonics, and lithospheric modification associated with the subduction of the Rivera Plate beneath the North American Plate. This study integrates geological, petrological, and aeromagnetic datasets to characterize the magmatic evolution and crustal structure beneath the Mascota region. Stratigraphically, the region comprises Cretaceous granitoids, metamorphic basement rocks, and thick silicic ignimbrites, overlain by Plio–Quaternary volcanic units of the Central Jalisco Volcanic Lineament (CJVL). The MVF hosts both potassic (minettes, absarokites) and calc-alkaline (basaltic andesites to andesites) lava types. K–Ar and ^40Ar/^39Ar dating indicate ages between 1.0 and 0.5 Ma, making Mascota the youngest volcanic center within the CJVL (Bandy et al., 2001; Ownby et al., 2008). Aeromagnetic interpretation reveals low-amplitude anomalies aligned northwest–southeast, coinciding with the structural graben system and suggesting that deep crustal fractures have been reactivated from older back-arc domains (López-Loera et al., 2022).Together, these data suggest that the Mascota region constitutes a key locality for understanding mantle metasomatism, fault-controlled magma ascent, and the geodynamic evolution of the western Jalisco Block.