Fluid network framing the hydrothermal system beneath Mt. Erciyes, Central Turkey

Abstract

<p>Fluid contribution in a tectonic process is a crucial parameter for characterization of its products. In the geophysical point of view, illustrating the electrical resistivity structure of any tectonic system can be used to determine effects of fluid contribution. Magnetotellurics is globally used to decipher characteristics of fault zones, volcanoes and hydrothermal systems which are related to driving tectonic regime in collision and transition zones. Mt. Erciyes, which is the largest composite volcano of the Central Anatolian Volcanic Province in Turkey, developed in two particular stages during the Quaternary. Igneous activities in Koçdağ and New Erciyes stages created a plausible environment to observe dominant calc-alkaline products while alkaline and tholeiitic components are also present in the region. Geochemical evidences offer that fractional crystallization combined with low degree crustal assimilation were experienced during the formation of the volcano in addition to potential magma mixing processes occurred in the magma chambers. As part of NSF-funded Continental Dynamics/Central Anatolian Tectonics Project (CD/CAT), this study aims to investigate electrical resistivity structure beneath Mt. Erciyes by means of three-dimensional modeling of the wide-band magnetotelluric data collected at 48 sounding locations. Current model depicts a high conductivity anomaly beneath Mt. Erciyes, which corresponds to its hydrothermal system and related clay cap. Within Erciyes pull-apart basin, local branches of Ecemiş Fault Zone that possibly reinforced the convenient setting for the upwelling of volcanic materials, bound the interconnected highly conductive zones in shallow depths. Under these circumstances, a complex resistivity distribution arises as a consequence of various electrical transfer mechanisms contemplated for the study region.</p>