Episodes 2022; 45(4): 377-389
Published online December 1, 2022
Copyright © International Union of Geological Sciences.
Tomasz Olichwer*, Robert Tarka
Institute of Geological Sciences, University of Wrocław, Pl. M. Borna 9, 50-204 Wrocław, Poland
Correspondence to:E-mail: firstname.lastname@example.org
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
The aim of article is determining the circulation depth and reservoir temperatures of thermal springs in the southern Spitsbergen using selected geothermometers which are in particular suitable for systems under low enthalpy conditions. For the analysis of the thermal waters circulation, the six thermal springs were selected. The conducted calculations of reservoir water temperatures for the thermal outflows showed that the most homogeneous temperature range was obtained for the Na-K-Ca, K-Mg, Ca-Mg, and Na-Li geothermometers as well as for the silica geothermometer using the mixing model. The derived temperature values demonstrate the existence of two depth zones of thermal water formation. The first shallower zone, up to a depth of 1.1 km, is associated with water circulation in the fault zones of metamorphosed carbonate rocks of the Hecla Hoek succession in the region of the Hornsund fjord and Raudfjellet massif. This zone is characterized by reservoir water temperatures of about 40°C. The second deeper zone of thermal waters in the Sørkappland area (Stormbukta area), with a temperature of about 80°C, corresponds to the groundwater reservoir located at a depth of 2.3 km. The thermal waters here are associated with sedimentary rocks of the late Paleozoic and early Mesozoic periods. Na-K geothermometer gives results consistent with the above-mentioned geothermometers only in the case of mature or partially mature waters (only Sørkappland area). Furthermore the original silica content (30 mg/kg) in the hot water, estimated by authors using mixing model, indicates that in the thermal water outflows of southern Spitsbergen the percentage of cold shallow circulation waters is about 85%, while the percentage of deep circulation thermal waters is 15%. The application of comprehensive solutions such as the simultaneous use of a number of different geothermometers, supported by the mixing models, allows us to determine temperatures in deep hot water reservoirs.