Insight Into Hartoušov Mofette, Czech Republic: Tales by the Fluids
The Cheb Basin (Czech Republic) is characterized by emanations of magma-derived gases and repeated occurrences of mid-crustal earthquake swarms with small to intermediate magnitudes (ML < 4.5). Associated intense mantle degassing occurs at the Hartoušov Mofette, a representative site for the...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2021-04-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2021.615766/full |
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| author | Kyriaki Daskalopoulou Heiko Woith Martin Zimmer Samuel Niedermann Johannes A. C. Barth Alexander H. Frank Andrea Vieth-Hillebrand Josef Vlček Cemile Dilara Bağ Cemile Dilara Bağ Ralf Bauz |
| author_facet | Kyriaki Daskalopoulou Heiko Woith Martin Zimmer Samuel Niedermann Johannes A. C. Barth Alexander H. Frank Andrea Vieth-Hillebrand Josef Vlček Cemile Dilara Bağ Cemile Dilara Bağ Ralf Bauz |
| author_sort | Kyriaki Daskalopoulou |
| collection | DOAJ |
| description | The Cheb Basin (Czech Republic) is characterized by emanations of magma-derived gases and repeated occurrences of mid-crustal earthquake swarms with small to intermediate magnitudes (ML < 4.5). Associated intense mantle degassing occurs at the Hartoušov Mofette, a representative site for the Cheb Basin. Here, we performed 14 sampling campaigns between June 2019 and March 2020. Gas samples of fluids ascending in two boreholes (F1, ∼28 m depth and F2, ∼108 m depth) and from a nearby natural mofette were analyzed for their chemical (CO2, N2, O2, Ar, He, CH4, and H2) and isotope compositions (noble gases and CO2). CO2 concentrations were above 99.1% in most samples, while O2 and N2 were below 0.6%. He ranged from 19 to 34 μmol/mol and CH4 was mostly below 12 μmol/mol. Isotope compositions of helium and carbon in CO2 ranged from 5.39 to 5.86 RA and from −2.4 to −1.3 ‰ versus VPDB, respectively. Solubility differences of the investigated gases resulted in fluctuations of their chemical compositions. These differences were accompanied by observed changes of gas fluxes in the field and at the monitoring station for F1. Variations in solubilities and fluxes also impacted the chemical concentration of the gases and the δ13C values that were also likely influenced by Fischer-Tropsch type reactions. The combination of (a) the Bernard ratio, (b) CH4/3He distributions, (c) P-T conditions, (d) heat flow, and (e) the sedimentary regime led to the hypothesis that CH4 may be of mixed biogenic and volcanic/geothermal origin with a noticeable atmospheric contribution. The drilling of a third borehole (F3) with a depth of ∼238 m in August 2019 has been crucial for providing insights into the complex system of Hartoušov Mofette. |
| first_indexed | 2024-12-14T02:26:59Z |
| format | Article |
| id | doaj.art-6b8f3824393640a980c6c561a7a95d58 |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-12-14T02:26:59Z |
| publishDate | 2021-04-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-6b8f3824393640a980c6c561a7a95d582022-12-21T23:20:22ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632021-04-01910.3389/feart.2021.615766615766Insight Into Hartoušov Mofette, Czech Republic: Tales by the FluidsKyriaki Daskalopoulou0Heiko Woith1Martin Zimmer2Samuel Niedermann3Johannes A. C. Barth4Alexander H. Frank5Andrea Vieth-Hillebrand6Josef Vlček7Cemile Dilara Bağ8Cemile Dilara Bağ9Ralf Bauz10GFZ German Centre for Geosciences, Potsdam, GermanyGFZ German Centre for Geosciences, Potsdam, GermanyGFZ German Centre for Geosciences, Potsdam, GermanyGFZ German Centre for Geosciences, Potsdam, GermanyGeoZentrum Nordbayern, Schlossgarten 5, Department Geographie und Geowissenschaften, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nürnberg, GermanyGeoZentrum Nordbayern, Schlossgarten 5, Department Geographie und Geowissenschaften, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nürnberg, GermanyGFZ German Centre for Geosciences, Potsdam, GermanyDepartment of Hydrogeology, Engineering Geology and Applied Geophysics, Faculty of Science, Charles University, Prague, CzechiaGFZ German Centre for Geosciences, Potsdam, GermanyDepartment of Geological Engineering, Middle East Technical University, Ankara, TurkeyGFZ German Centre for Geosciences, Potsdam, GermanyThe Cheb Basin (Czech Republic) is characterized by emanations of magma-derived gases and repeated occurrences of mid-crustal earthquake swarms with small to intermediate magnitudes (ML < 4.5). Associated intense mantle degassing occurs at the Hartoušov Mofette, a representative site for the Cheb Basin. Here, we performed 14 sampling campaigns between June 2019 and March 2020. Gas samples of fluids ascending in two boreholes (F1, ∼28 m depth and F2, ∼108 m depth) and from a nearby natural mofette were analyzed for their chemical (CO2, N2, O2, Ar, He, CH4, and H2) and isotope compositions (noble gases and CO2). CO2 concentrations were above 99.1% in most samples, while O2 and N2 were below 0.6%. He ranged from 19 to 34 μmol/mol and CH4 was mostly below 12 μmol/mol. Isotope compositions of helium and carbon in CO2 ranged from 5.39 to 5.86 RA and from −2.4 to −1.3 ‰ versus VPDB, respectively. Solubility differences of the investigated gases resulted in fluctuations of their chemical compositions. These differences were accompanied by observed changes of gas fluxes in the field and at the monitoring station for F1. Variations in solubilities and fluxes also impacted the chemical concentration of the gases and the δ13C values that were also likely influenced by Fischer-Tropsch type reactions. The combination of (a) the Bernard ratio, (b) CH4/3He distributions, (c) P-T conditions, (d) heat flow, and (e) the sedimentary regime led to the hypothesis that CH4 may be of mixed biogenic and volcanic/geothermal origin with a noticeable atmospheric contribution. The drilling of a third borehole (F3) with a depth of ∼238 m in August 2019 has been crucial for providing insights into the complex system of Hartoušov Mofette.https://www.frontiersin.org/articles/10.3389/feart.2021.615766/fullgeogenic degassingCO2-rich fluidssolubilityCHcpsdummy4 origingas flow perturbations |
| spellingShingle | Kyriaki Daskalopoulou Heiko Woith Martin Zimmer Samuel Niedermann Johannes A. C. Barth Alexander H. Frank Andrea Vieth-Hillebrand Josef Vlček Cemile Dilara Bağ Cemile Dilara Bağ Ralf Bauz Insight Into Hartoušov Mofette, Czech Republic: Tales by the Fluids Frontiers in Earth Science geogenic degassing CO2-rich fluids solubility CHcpsdummy4 origin gas flow perturbations |
| title | Insight Into Hartoušov Mofette, Czech Republic: Tales by the Fluids |
| title_full | Insight Into Hartoušov Mofette, Czech Republic: Tales by the Fluids |
| title_fullStr | Insight Into Hartoušov Mofette, Czech Republic: Tales by the Fluids |
| title_full_unstemmed | Insight Into Hartoušov Mofette, Czech Republic: Tales by the Fluids |
| title_short | Insight Into Hartoušov Mofette, Czech Republic: Tales by the Fluids |
| title_sort | insight into hartousov mofette czech republic tales by the fluids |
| topic | geogenic degassing CO2-rich fluids solubility CHcpsdummy4 origin gas flow perturbations |
| url | https://www.frontiersin.org/articles/10.3389/feart.2021.615766/full |
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