Unraveling the electrical conductivity structure to decipher the hydrothermal system beneath the Mt. Hasan composite volcano and its vicinity, SW Cappadocia, Turkey

Abstract

To comprehend the hydrothermal potential beneath the Mt. Hasan composite volcano and its vicinity, three-dimensional analyses of magnetotelluric data collected at 27 sounding locations were utilized to develop electrical conductivity (or its reciprocal resistivity) images in southwest Cappadocia, Central Anatolia, Turkey. A low resistivity anomaly associated with a clay cap was observed in the resulting numerical models that followed the characteristics of the earlier theoretical models developed for the electromagnetic interpretation of hydrothermal systems. The observed anomaly appeared in the form of a deep smectite, smectite–illite, and illite–chlorite sequence buried under the cover layers made up of welded ignimbrites, contemporaneous sediments, and monogenetic Quaternary volcanism products. Further evidence was observed that indicated the presence of a relatively deep (~4–6 km), single magmatic chamber beneath Mt. Hasan and the surrounding system. The Tuz Gölü Fault and some other auxiliary faults within this system, present a high correlation with the low-to-high resistivity interfaces in the vicinity of Mt. Hasan.