caa a22 4500 606149899 CHVBK 20210128100536.0 cr unu---uuuuu 210128e20151101xx s 000 0 eng 10.1007/s00531-014-1140-4 doi (NATIONALLICENCE)springer-10.1007/s00531-014-1140-4 CO2 degassing in the Hartoušov mofette area, western Eger Rift, imaged by CO2 mapping and geoelectrical and gravity surveys [Elektronische Daten] [Tobias Nickschick, Horst Kämpf, Christina Flechsig, Jan Mrlina, Jens Heinicke] Strong, subcontinental mantle-dominated CO2 degassing occurs in the Hartoušov and Bublák mofette fields in the western Eger Rift. The combination of CO2 gas flux and soil gas measurements as well as gravity and geoelectric surveys provides insight into the surface and subsurface of this unique mofette area. CO2 soil gas and gas flux measurements reveal that large amounts of carbon dioxide are released via channels with diameters below 1m. Carbon dioxide emissions of several tens and up to more than 100kgday−1 are ejected via these small seeps. Measurements with small spacings are necessary to account for the point like, focused gas discharge in the lesser degassing surrounding. We estimate that between 23 and 97 tons of CO2 are released over an area of about 350,000m2 each day in the Hartoušov mofette field. The application of widely used geostatistical tools leads to estimations of the CO2 discharge with very high standard deviations due to the strong positive skewness of the data distribution. Geophysical investigations via electrical resistivity tomography and gravity measurements were carried out over areas of strong seepage and reveal distinct anomalies in the subsurface below mofettes, indicating rock and sediment alterations and/or sediment transport by pressurised, ascending CO2 and water mobilised by it. This study reveals that the gas emanations only occur west of a morphological step which is related to a N-S-oriented fault zone, the Počatky-Plesná fault zone. The results of CO2 mapping and the geophysical studies can track the course of this fault zone in this area. Our results fit into a tectonic model in which the mofette fields are in the centres of two independent pull-apart basin-like structures. We hypothesise that the sinistral strike-slip movement of the Počatky-Plesná fault zone leads to a pull-apart basin-like opening, at which the strong, mantle-derived CO2 degassing occurs nowadays. Since the Hartoušov and Bublák mofette fields only illustrate examples along the N-S-striking Počatky-Plesná fault zone, its role and other N-S-striking faults' roles of the Regensburg-Leipzig-Rostock zone for upper mantle degassing might have been underestimated previously. Springer-Verlag Berlin Heidelberg, 2015 Cheb Basin nationallicence Magmatic CO2 nationallicence Eger Rift nationallicence CO2 gas flux studies nationallicence Geoelectrics nationallicence Gravity nationallicence Nickschick Tobias German Research Centre for Geosciences GFZ Potsdam, Section4.3 Telegrafenberg, 14473, Potsdam, Germany aut Kämpf Horst German Research Centre for Geosciences GFZ Potsdam, Section4.3 Telegrafenberg, 14473, Potsdam, Germany aut Flechsig Christina University Leipzig, Institute for Geophysics and Geology, Talstraße 35, 04103, Leipzig, Germany aut Mrlina Jan Czech Academy of Sciences, Institute of Geophysics, Bocni II 1401, 14131, Prague, Czech Republic aut Heinicke Jens University Leipzig, Institute for Geophysics and Geology, Talstraße 35, 04103, Leipzig, Germany aut International Journal of Earth Sciences Springer Berlin Heidelberg 104/8(2015-11-01), 2107-2129 1437-3254 104:8<2107 2015 104 531 https://doi.org/10.1007/s00531-014-1140-4 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00531-014-1140-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Nickschick Tobias German Research Centre for Geosciences GFZ Potsdam, Section4.3 Telegrafenberg, 14473, Potsdam, Germany aut NATIONALLICENCE 700 1- Kämpf Horst German Research Centre for Geosciences GFZ Potsdam, Section4.3 Telegrafenberg, 14473, Potsdam, Germany aut NATIONALLICENCE 700 1- Flechsig Christina University Leipzig, Institute for Geophysics and Geology, Talstraße 35, 04103, Leipzig, Germany aut NATIONALLICENCE 700 1- Mrlina Jan Czech Academy of Sciences, Institute of Geophysics, Bocni II 1401, 14131, Prague, Czech Republic aut NATIONALLICENCE 700 1- Heinicke Jens University Leipzig, Institute for Geophysics and Geology, Talstraße 35, 04103, Leipzig, Germany aut NATIONALLICENCE 773 0- International Journal of Earth Sciences Springer Berlin Heidelberg 104/8(2015-11-01), 2107-2129 1437-3254 104:8<2107 2015 104 531