STRUCTURAL GEOMETRY OF THE PATHE GEOTHERMAL FIELD

CARRILLO, M., Eugenia 406-502, Col. del Valle, Mexico, D.F. 03100

mcm@servidor.unam.mx.

In the bordering area of Hidalgo and Queretaro States, Central Mexico, the Pathe geothermal field is located at the intersection of the seismological actives Aljibes half graben (Ahg) and the San Francisco graben. These faults running roughly east-west and north-south were cut into Cretaceous and upper tertiary rocks. The Ahg master fault dips 45 degrees toward the south and shows a roll-over anticline in the foot wall region whereas subsidiary normal faults are righteous. A semibalanced cross section considers the Ahg master fault as a listric fault whose flat region occurs at 3600 m below the sea level the same depth of the Laramide Sierra Madre Oriental decollement. These structural features suggest that the Ahg master fault is a collapsing Laramide thrust.