Geologic and Thermal Evolution of Turkeys Wealthy Geothermal Region, MMM

Abstract

Recently, Menderes Metamorphic Massive (MMM) had been subjected to a fast structural evolution. This part of Western Anatolias lithospheric crust has risen more than ten kilometers since post Miocene and this movement is continuing. This uplift has been compensated by a progressive erosion, detachment faults, listric faults, etc. and has been happened in several cycles.
This fast exhaustion of the upper crust in a relatively short period results in a disturbance of the thermal framework of this section. The cooling history of MMM has been remodeled by thermochronological methods and at least two main fast cooling phases have been determined.
A cooling model of the lithospheric crust shows a delayed stabilisation of the thermal gradient caused a high heat flow at this region. This heat flow is irregularly distributed at MMM.
In addition to this region’s high heat flow, a dense framework of faults with different orientations provide a well developed vertical permeable channel system. This allows fluids to infiltrate to sufficient depths to be charged with a considerable amount of heat by interaction with rocks of this warm upper crust.
Thus, more than fifteen medium-entalphy, water-dominated geothermal systems have been found along two E-W oriented long grabens at MMM. These systems occur at the southern side of northern and northern side of southern grabens, at the two borders of the mostly exhausted core complex of MMM.
This geological, structural and thermal framework provides a promising prospect for enhanced geothermal field development studies at the zone extending between these two graben belts where the mostly exhausted part of the MMM spread.