Geothermal Model of the Shallow Crustal Structure across the “Mountain Front Fault” in Western Lurestan, Zagros Thrust Belt, Iran

Abstract

The Zagros thrust belt is a zone of deformed crustal rocks well exposed along the southwest region of Iran. To obtain a better knowledge of this mountain chain, we elaborated a 2D model reproducing the thermal structure of the “Mountain Front Fault”. This study, which is focused on the Lurestan region, is based on a model made by merging published sections and available information on the depth of the Moho. We present the isotherms and the geotherms calculated using an analytical methodology. The calculation procedure includes the temperature variation due to the re-equilibrated conductive state after thrusting, frictional heating, heat flow density data, and a series of geologically derived constraints. In order to perform the temperature calculations, the crustal structure in the Lurestan region is simplified as composed of two domains: A lower unit made by crystalline basement and an upper unit including all the lithostratigraphic units forming the sedimentary cover. The resulting model is compared with the numerical results obtained by previous studies to improve the description of the thermal structure of this geologically important area.