Hydrogeochemistry and origin of carbonated, sulfated, and saline geothermal waters, Central Anatolia, Türkiye

Authors : Mustafa Afşin, Murat Kavurmacı, Ali Gürel, Ümmühan Gökçen Duru, Özcan Oruç

Pages : 1374-1382

Doi:10.65206/pajes.84780

View : 245 | Download : 365

Publication Date : 2025-12-17

Article Type : Research Paper

Abstract :This study aims to compare the geothermal waters of Gümüşkent (GK), Koçpınar (KP), Dertalan (DA), Terme (TE), Kozaklı (KZ), Bayramhacı (BH), Karakaya (KK), Tuzlusu (TZ), Ziga (ZG), Narlıgöl (NG), Yeşilhisar (YH), and Kemerhisar (KH), which exhibit temperatures ranging from 17.5 °C to 86 °C. Additionally, the origins of these waters are evaluated by taking into account the cold waters of Helvadere (HD), Dokuzpınar (DP), Terme (TES), and Kozaklı (KOS), with temperatures between 10.4 °C and 13.09 °C, all located in Central Anatolia. The aquifers of these fault-controlled waters are of Paleozoic marbles and Eocene limestones; cover rocks are impermeable units. The heat production system of these waters may be due to young volcanism and granitic/syenitic intrusions as well as radiogenic sources. The types of these carbonated, sulfated, and saline waters are Ca-HCO3 in KP, GK, BH, and TE; Na-SO4 in KZ; Ca-SO4 in DA; Na-Cl in TZ, ZG, NG, KH, KK, and YH, respectively. These waters, which are of meteoric origin in terms of isotopic (δ18O and δ2H), generally have deep circulation and slow flow. The main reason for the deviation observed from the meteoric water line in some waters is evaporation. In KH, YH, and KK with low temperatures, the mineralization of these waters increased as a result of long-term gas-rock-water interaction. The causes of salinization in the Na-Cl-type waters may be the dissolution of halite minerals and the mixing of older waters trapped at depth during the closure of the Tuzgölü and salt domes in the TZ and ZG, the Central Kızılırmak basin in the YH and KK, and the Ulukışla basin in the KH. According to δ13C (‰PDB) values, the sources of CO2 gas in waters may be geogenic (marble, marine and lacustrine limestone) and/or mantle. According to δ34S‰VCDT values, the source of sulfate in waters may be evaporitic rocks in KK, ZG, KZ, TZ, KH, and volcanic and/or carbonate rocks in other waters. The 14C ages of the waters are lowest in DA (19.15 ka) and highest in KK (45.11 ka). The calculated ages are apparent because the 14C values of the waters in question are often a measure of the contribution of modern biogenic carbon to the total dissolved carbonate or bicarbonate. In this context, the waters examined may be old waters that entered the system from the late Pleistocene to the early Holocene periods.
Keywords : Jeotermal sular, Karbon ve sülfür izotopları, Hidrojeokimya, Orta Anadolu

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