The Tectonic and Magneto-Telluric Survey Effects on the Geothermal Explorations Around the Menderes Massif in the Western Anatolia, Turkey

摘要

Western Anatolia is one of the most active tectonic and seismic areas of the world, and has important geothermal potential. As indicated in several related articles, the area is characterized by high heat flow over a wide area suggesting regional geothermal potential. Although surface manifestations are lacking in many areas, several deeper geothermal reservoirs may be hidden and a few of them have been discovered recently. The lack of wide-spread surface manifestations means that the regional tectonics, resistivity (through magneto-tellurics), geochemistry and seismic reflection surveys are important methods in exploring for geothermal resources in Anatolia. Seismic methods are more expensive and are being used in exploring for potential EGS systems. Reflection seismics have been applied in petroleum exploration in Turkey and that the data are available and are being reviewed to determine the structures that might control geothermal circulation. BM Holding has been exploring geothermal resources around the Menderes Massif since 2005. Exploration in the Menderes Massif has been guided by understanding, the young structural picture and the regional tectonics of western Anatolia and the Aegean region. In extensional tectonic regions as in the western Anatolia of Turkey, geothermal systems located in areas of complex vertical and horizontal tectonics may be mixed and re-equilibrated geochemically due to the different permeability environments. Conventional surface geochemistry methods conducted along surface may not be enough to explore deeper and hotter geothermal reservoirs. Magnetotelluric methods applied to the metamorphic complexes such as Menderes Massif may be strongly influenced by the graphitic contents of the basement metamorphic rocks. Low resistivity anomalies within Menderes grabens also may be misleading because of superimposed basins and extraordinary sediment/ clay thicknesses. Resisting a fall into "anomaly hunting" requires thatseveral common exploration methods may be eliminated or combined in depending on the geological conditions.