{"title":"Isotope and hydrochemical characteristics of thermal waters along the active fault zone (Erzin-Hatay/Turkey) and their geothermal potential","authors":"DİDEM YASİN, GALİP YÜCE","doi":"10.55730/1300-0985.1871","DOIUrl":null,"url":null,"abstract":"Geochemical investigations carried out on thermal waters over the Erzin-Hatay area allowed the collection of a suite of 9 samples from natural springs and one well characterized by outlet temperatures in the range from 19.6 to 31.5 °C. All of the springs have slightly acidic pH (in the range of 6) but one sample was marked by a pH value >11 as a consequence of serpentinization processes. The water chemistry denotes water/rock interactions with either magmatic or carbonatic rocks in a water reservoir equilibrated at temperatures estimated to be in the range of 58-162 °C. The stable isotope composition of the collected waters, in terms of dD and d18O, denotes a recharge from local meteoric waters. The dissolved gases denote the contribution of no atmospheric components. CO2 is the dominant dissolved component for most of the sample, while methane is the major component for the thermal water involved in serpentinization. Besides the main components CO2 and CH4 , the dissolved gases show significant concentrations of He, H2, and CO. The isotopic composition of helium shows 3 He/4 He ratios well above that of Air Saturated Waters (ASW = 1.39 × 10-6) clearly indicating a significant contribution of 3 He of mantle origin. Taking into account the location of some sampling sites nearby the Düziçiİskenderun Active Fault Zone and the associated mantle helium contribution, we propose that fluids/faults relationships have to be considered as responsible for the feeding of deep-originated fluids to the shallow groundwater. As mantle-derived fluids are also carriers of thermal energy, the collected results strongly suggest improving the knowledge of the study area, where hydrological and geochemical considerations coupled with the tectonic setting of the area should focus on the geothermal potential of the circulating waters.","PeriodicalId":49411,"journal":{"name":"Turkish Journal of Earth Sciences","volume":"52 1","pages":"0"},"PeriodicalIF":1.3000,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Turkish Journal of Earth Sciences","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.55730/1300-0985.1871","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Geochemical investigations carried out on thermal waters over the Erzin-Hatay area allowed the collection of a suite of 9 samples from natural springs and one well characterized by outlet temperatures in the range from 19.6 to 31.5 °C. All of the springs have slightly acidic pH (in the range of 6) but one sample was marked by a pH value >11 as a consequence of serpentinization processes. The water chemistry denotes water/rock interactions with either magmatic or carbonatic rocks in a water reservoir equilibrated at temperatures estimated to be in the range of 58-162 °C. The stable isotope composition of the collected waters, in terms of dD and d18O, denotes a recharge from local meteoric waters. The dissolved gases denote the contribution of no atmospheric components. CO2 is the dominant dissolved component for most of the sample, while methane is the major component for the thermal water involved in serpentinization. Besides the main components CO2 and CH4 , the dissolved gases show significant concentrations of He, H2, and CO. The isotopic composition of helium shows 3 He/4 He ratios well above that of Air Saturated Waters (ASW = 1.39 × 10-6) clearly indicating a significant contribution of 3 He of mantle origin. Taking into account the location of some sampling sites nearby the Düziçiİskenderun Active Fault Zone and the associated mantle helium contribution, we propose that fluids/faults relationships have to be considered as responsible for the feeding of deep-originated fluids to the shallow groundwater. As mantle-derived fluids are also carriers of thermal energy, the collected results strongly suggest improving the knowledge of the study area, where hydrological and geochemical considerations coupled with the tectonic setting of the area should focus on the geothermal potential of the circulating waters.
期刊介绍:
The Turkish Journal of Earth Sciences is published electronically 6 times a year by the Scientific and Technological Research
Council of Turkey (TÜBİTAK). It is an international English-language journal for the publication of significant original recent
research in a wide spectrum of topics in the earth sciences, such as geology, structural geology, tectonics, sedimentology,
geochemistry, geochronology, paleontology, igneous and metamorphic petrology, mineralogy, biostratigraphy, geophysics,
geomorphology, paleoecology and oceanography, and mineral deposits. Contribution is open to researchers of all nationalities.