Electrical resistivity structure beneath MT. Erciyes Central Anatolia, Turkey

Abstract

The Central Anatolia (CA) is an intermediate belt between the Pontides and the Anatolide-Tauride blocks. Numerous basins, folds, faults, volcanic fields and rich mineral resources in the region have attracted the attention of geoscientists for years. Mt. Erciyes is a Quaternary-aged stratovolcano located in CA, which has not been activated for a long time. in this thesis, I aimed to perform three-dimensional (3 - D) imaging of its electrical properties using magnetotellurics (MT) and interpret its structure. MT method has been extensively used in the exploration of volcanic areas. This study can be considered as the first systematic application of the MT performed in the vicinity of Mt. Erciyes. Between 2013 and 2018, deploying 48 wide­band MT soundings forming a grid surrounding the volcano and its location as part of the Continental Dynamics/Central Anatolian Tectonics project (CD/CAT). The obtained data set was used for determining the dimensionality of the survey area, and the realistic electrical structure of the region was achieved with 3 - D solution algorithms including 38 station data. The results showed that the regional geoelectric strike direction is ~ N25° E which coincides with the structural strike of the region. For determining the dimensionality of the MT data, phase tensor analyses were performed. The observed wide-band data were inverted using a 3 - D inversion algorithm known as the MODEM © in two distinct ways; with and without topography information to reveal the electrical structure. The 3 - D inversion results revealed three distinct conductivity features: a widespread conductive anomaly found beneath the volcano and two conductive areas in the vicinity of the volcano. When the final model is examined, it is possible to observe that the conductive regions are separated from each other. lf the final model is examined together with the geological data, it is noticed that the boundaries of the conductor coincide with the faulting in the region.