Inspecting the Mahallat Geothermal Field (at the Center of Iran) Through Geological and Geochemical Analysis

Abstract

The Mahallat Geothermal Filed is known as one of the largest national prospects located in the Markazi Province at the center of Iran. Detailed geological and geochemical analysis have been performed to know this region deeper. To achieve this aim, a 1: 20000 geological map of studied area has been prepared and also all geothermal surface manifestations have been identified and marked in the map. Hot springs and pervasive travertine deposits can be addressed as the most important surface manifestations, so that one of the largest travertine outcrops in the world is formed and deposited through existing hot springs. Geochemical sampling and analysis have been carried out on 5 hot springs with temperature range from 35 to 47 °C. Results of geothermometry studies revealed the existence of a low temperature geothermal reservoir (about 100 °C) in this area. Regarding to the tectonic studies, major faults of this area have played the most important role in the formation of the Mahallat geothermal reservoir, and this prospect falls into the Convective fracture controlled geothermal system with deep circulating water.