The Auca Mahuida volcano (2.03–0.88 Ma) located east of the Andean thrust front in the; Neuqu´en basin (Argentina) hosts an oil system of thermogenic origin and is affected by the; NW–SE striking-faults. Intrusive bodies and the underlying Jurassic sediments constitute the; reservoir rocks. Aeromagnetic data collected in the Auca Mahuida area detected multiple; dipolar magnetic anomalies, many of which have reverse polarity. Palaeomagnetic measurements; on rock samples collected in the field together with available age determinations indicate; that the reversely magnetized sources were mainly emplaced during the Matuyama reverse; polarity chron while the normal polarity sources were emplaced during the Olduvai and/or; Jaramillo subchrons. The location and geometry of the intrusive bodies is poorly known and; the customary magnetic inversion is rendered difficult because of multiple natural remanent; magnetization directions. To address these difficulties, a voxel inversion was applied to model; the vector residual magnetic intensity (VRMI) transformation of the observed total magnetic; intensity data. The modelling showed a 1.5 km deep, subcircular ring-shaped intrusion below; the summit of the volcano and a series of NW–SE elongated, fault-controlled intrusive bodies; to depths up to 3–4 km. Our results show that magnetic data and VRMI modelling help resolve; the geometry of the shallow plumbing system of volcanoes with remanently magnetized; sources, and estimate the depth and geometry of potential oil reservoirs in volcanic areas.Facultad de Ciencias Astronómicas y Geofísicas