Investigation of the Galatian volcanic complex in the northern central Turkey using potential field data

The Galatia volcanic complex (GVC) is one of two important volcanic complexes located in central Anatolia, Turkey. The study of potential field data can yield useful information about the subsurface magnetisation and density distribution. In this paper, a study of the thermal structural setting of the GVC using the analysis and interpretation of aeromagnetic data is presented. Volcanic rocks are the main cause of the magnetic anomalies that occur in the study region. A Curie-point-depth (CPD) map was constructed using the azimuthally averaged power spectrum of aeromagnetic anomaly data that was reduced-to-the-pole transformed (RTP); the map shows high geothermal potential for the GVC. The Curie point depths vary from about 6.74 km to 16.9 km and are consistent with the results of previous geothermal studies. The GVC exhibits low CPD and high heat-flow values (>100 mW m−2). The CPD suggested that deep-seated magnetised sources continue downward up to 10 km (inside the upper crust). A horizontal gradient analytic signal (HGAS) map exhibits the images and locations of deep-seated magnetised sources. In addition, the CPD and average Moho depth (33 km, calculated from gravity anomaly data) are used to determine the presence of magnetic and non-magnetic crust in two cross sections taken from the GVC. The results presented should shed considerable light on some aspects of geothermal exploration in the GVC.

▶ The average bottom depth of the magnetic sources from the Curie-point depth analysis of a magnetic anomaly is 10.68 km. ▶ Moho depths in the Galatian volcanic complex (GVC) estimated from the gravity anomalies range between about 32 km and about 35.5 km. ▶ The magnetic depths in the Galatian volcanic complex (GVC) determined from the Curie isotherm go down to about 17 km. ▶ The magnetic crust in the study region is located at the upper crust.