Three-Dimensional Temperature Simulations of the Acoculco Caldera Complex, Puebla, Mexico

Abstract

Three-dimensional temperature simulations of the Acoculco caldera complex are undertaken to improve our understanding of its thermal regime. Aeromagnetic data are processed to estimate the depth of the Curie isotherm with Okubo method. The isotherm is then used as a bottom boundary condition of the heat transfer equation which is solved in steady state with Finite Volume numerical scheme. Local scale thermal anomalies, not detected by the available aeromagnetic surveys, are considered in the model based on petrological evidence. The description of the structures controlling the heat flow is based on limited borehole data along with geophysical surveys. The resulting computational model is intended to be an instrument to test assumptions on the thermal regime in the ACC. Additionally, it is a framework to study the relation between heat flow measurements and the base of the magnetic body that can be applied to other study areas. In the case of the ACC, the numerical results show that local thermal anomalies are necessary to attain the high geothermal gradients that have been measured in the area. These anomalies turn out to be shallower than those assumed in previous 1D thermal models in this caldera complex.