An active subcontinental mantle volatile system in the western Eger rift, Central Europe: gas flux, isotopic (He, C, and N) and compositional fingerprints

Intraplate seismicity in the western Bohemian Massif (central Europe): A possible correlation with a paleoplate junction

“…Dotted lines show an asthenospheric updoming estimated by Heuer et al (2006) from P-receiver functions. Double arrows on the top indicate extents of the Eger Rift and of major escape centers of mantle CO 2 and 3 He determined by Weinlich et al (1999) and showed also in the map view in Figure 2. The geometry of the Mariánské Lázně Complex (MLC) is drawn after Tomek et al (1997) and Švancara et al (2000), the ST crust underthrusted beneath the MLC and TBU crust is after Tomek et al (1997).…”

“…The post-Alpine crustal extension of rift systems is associated with an enhanced release of CO 2 and variable fractions of mantle-derived He (for review see Weinlich et al, 1999,). Newell et al (2005) show that in western North America the highest contribution of mantle helium correlates to the youngest and most active tectonic regions and domains of the lowest mantle velocity.…”

“…The Tertiary Eger (Ohře) Rift (ER), a 300 km long ENE-WSW striking structure characterized by high heat flow and Cenozoic volcanism is part of the European Cenozoic Rift System (ECRIS; Prodehl et al, 1995) and its formation is thought to be related to Alpine collision (Ziegler, 1992; see also review of the ER development in Geissler et al, 2005). Active tectonics is primarily manifested by frequent weak to moderate earthquake swarms (Horálek et al, 2000), emanations of CO 2 dominated gases of mantle origin (Weinlich et al 1999;Bräuer et al, 2003), and by neotectonic crustal movements (Bankwitz et al, 2003). The post-rift uplift of the Krušné hory Mts.…”

Mantle-related CO2, metasedimentary HC-N2gas and oil traces in the Répcelak and Mihályi accumulations, W-Hungary — mixing of three fluids of very different origin

“…According to Weinlich et al (1999) the Bublák mofetta, the most intense of the mofettas active in the western Eger rift (Czech Republic), sourced by a cooling intrusive body present in the subcontinental mantle, is delivering CO 2 into the atmosphere at a rate of 28 m 3 /h. Supposing such a rate of trapping, about 20 and 25 ky would have been necessary for the accumulation of the approximately 5.5 and 7 Md m 3 CO 2 gas at Répcelak and Mihályi (Fig.…”

Seismically triggered microbial methane production relating to the Vogtland NW Bohemia earthquake swarm period 2000, Central Europe

“…The main component CO 2 is characterised by a δ 13 C value of -4.7‰ and the 3 He/ 4 He ratio yields 2.4 (R/Ra). Weinlich et al (1999) presented an extensive characterisation of free gas exhalations in Vogtland and NW Bohemia, including several mineral springs in Bad Brambach. CO 2 is the main component of all the locations there, and it was shown that the CO 2 stems from the upper mantle.…”