Fault-controlled magmatic architecture beneath the Zacapú basin (central Trans-Mexican Volcanic Belt field) from 3D aeromagnetic modeling

Abstract

The Michoacán–Guanajuato Volcanic Field (MGVF), within the Trans-Mexican Volcanic Belt (TMVB), is one of the world’s largest monogenetic volcanic provinces. Here, we analyze SGM 1998 airborne aeromagnetic data acquired over the western Zacapú sector and integrate map-based filtering with 3D magnetic susceptibility inversion to constrain subsurface magmatic architecture and structural controls. Residual magnetic anomalies (up to ~+ 570 to − 412 nT) and reduction-to-the-pole maps upward continued to 3 km delineate three aeromagnetic domains (AMD I–III) with contrasting anomaly amplitudes and spatial organization. Analytic-signal processing and upward continuation to 10 km emphasize two dominant lineament sets (NW–SE and NE–SW) and a major NW–SE-trending discontinuity interpreted as a deep zone of crustal weakness. VOXI 3D inversion resolves multiple magnetized bodies: Body W1 is a large, irregular source with upper apophyses, extending from ~1887 to at least ~10,280 m.b.s.l. and remaining open at depth, whereas W2 is an elongate, N–S-trending body with a maximum length of ~25 km and a depth extent of ~11 km. Together, these results indicate that volcanism in the Zacapú sector reflects interaction between deep magma storage and regional structures that localize magma ascent and emplacement.