Geophysical determination of the Jalisco and Michoacán blocks boundaries along the Colima Graben

The Colima Graben is located in the southwestern part of Mexico, extending from the triple junction of the grabens of Citlala (located Southwest of the Chapala Graben), Colima and Tepic-Zacoalco south of Guadalajara, to the Mesoamerican Trench (MAT) south of Manzanillo on the Pacific coast. The Colima Graben is spatially related to the boundary between the Jalisco and Michoacán Blocks, which has been interpreted as an area of crustal rupture that facilitates the rise of upper mantle material, making it difficult to identify surface evidence to determine the limits of the Jalisco and Michoacán Blocks. The use of gravity and magnetic data inversions, make posible the determination of the boundary geometry of the two blocks, evidencing the crustal discontinuity through the contrast in density and magnetic susceptibility over the fracture zones.