Hydrogeochemical conditions of submarine and terrestrial karst sulfur springs in the Northern Adriatic

Šušmelj, Kaja (author), Čenčur Curk, Barbara (author), Kanduč, Tjaša (author), Rožič, Boštjan (author), Verbovšek, Timotej (author), Vreča, Polona (author), Žagar, Klara (author), Žvab Rožič, Petra (author)

Submarine springs near Izola, in the Northern Adriatic Sea, appear in funnel-shaped depressions and smell strongly of sulfur. Along the Mediterranean coast there are many submarine karst springs containing brackish or fresh water, but submarine sulfur springs are not particularly common. Three submarine sulfur springs and one terrestrial sulfur spring were investigated to better understand the water properties, water–rock interaction within the aquifer, and to explore the origin of the spring water. Groundwater and seawater samples were also collected for comparison. Based on the geological setting, physicochemical parameters, hydrogeochemical data, and stable isotope data (δ$^{18}$O, δ$^2$H, δ$^{13}$C$_{DIC}$, δ$^{34}$S$_{SO4}$, δ$^{18}$O$_{SO4}$), we can affirm that (1) the large concentration of seawater in the submarine springs samples is due to sampling challenges; (2) springs recharge from precipitation where confined karst aquifers outcrop; (3) deep water circulation is indicated; (4) redox conditions can provide a suitable environment for bacterial reduction of the marine or organic sulfate to the odorous H$_2$S; (5) geological data suggests that the coals beneath the alveolinic-nummulitic limestones are the source of sulfur. A multi-parameter and interdisciplinary approach has proven important in assessing submarine sulfur springs affected by seawater input.

• Language: English
• Keywords: terrestrial and submarine sulfur springs, karst groundwater, hydrogeochemistry, stable isotopes, Slovenia
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: 18 str.
• Numbering: Vol. 83, iss. 7, art. 214
• PID: 20.500.12556/RUL-156152
• UDC: 55
• ISSN on article: 1866-6280
• DOI: 10.1007/s12665-024-11476-7
• COBISS.SI-ID: 190295043
• Publication date in RUL: 10.05.2024

Record is a part of a journal

• Title: Environmental Earth sciences
• Publisher: Springer Nature
• ISSN: 1866-6280
• COBISS.SI-ID: 1683797

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