Curie point depth, heat-flow and radiogenic heat production deduced from the spectral analysis of the aeromagnetic data for geothermal investigation on the Menderes Massif and the Aegean Region, western Turkey

Abstract

In this study, the Curie point depth (CPD), heat-flow and radiogenic heat production maps of the Menderes Massif (MM) and the Aegean Region-Turkey were prepared for the thermal crustal structure from the aeromagnetic data by means of a spectral analysis method. The estimated CPDs in the study area vary from 6.21 to 12.41km. The heat-flow values were calculated for two (2) different thermal conductivities of 2.5–2.7Wm−1K−1. The radiogenic heat production was also calculated between 0.38 and 0.80μWm−3 on the high-grade metamorphic units of the study area. The estimated heat-flow and radiogenic heat production maps indicate that a high temperature in the upper crust and thin lithosphere in the observation area are probably resulted from the crustal extension, active deformation and magmatism. All of the produced maps in this study were correlated with the analytic signal (AS) map which indicates the locations of the bodies causing magnetic anomalies. In addition, maxspots of the horizontal gradients from the magnetic anomalies were also emplaced onto the produced maps to indicate the boundaries of critical magmatic units in the study area. These correlations allow reasonable and meaningful interpretation for the reasons of high geothermal gradient and high heat-flow. In addition, a longitudinal seismic wave (Vp velocity) map was presented from the relationship between seismic velocity and radiogenic heat production in the western Anatolia, for the first time and they were correlated with the previous investigations. The estimated Vp velocities range from about 6 to 6.4km/sn and low Vp values may be related to the partial melting of subducted structures in the western Anatolia. As a result, two new potential geothermal areas were determined by the integration of different methods used in this study.