Details zur Publikation

Referenztyp Zeitschriften
DOI / URL Link
Titel (primär) Natural laboratory NW Bohemia: comprehensive fluid studies between 1992 and 2005 used to trace geodynamic processes
Autor Bräuer, K.; Kämpf, H.; Niedermann, S.; Strauch, G.; Tesař, J.;
Journal / Serie Geochemistry Geophysics Geosystems
Erscheinungsjahr 2008
Department HDG;
Band/Volume 9
Heft 4
Sprache englisch;
Keywords fluid monitoring; magmatic CO2; 3He/4He ratios; triggered seismicity; magma reservoir; European Cenozoic rift
Abstract Comprehensive studies of CO2-rich fluids close to the swarm earthquake region Nový Kostel at the Czech-German border have been started 15 years ago and have in particular included two extended chemical and isotope monitoring studies lasting for several years each. The regional surface distribution patterns of the fluid signatures including the identification of the origin of fluid components are the focus of the detailed studies. Three degassing centers (Cheb basin, Mariánské Lázne, and Karlovy Vary) with high CO2 flux and the same level of d 13C values, but different levels of 3He/4He ratios, have been identified. The studies have located the CO2 source and have investigated seismically induced changes in fluid characteristics on the basis of unique weekly sampling campaigns at selected locations. A seismically triggered release of crustal helium was confirmed by both monitoring campaigns. Finally, indications for a presently active magmatic process beneath the Cheb basin have been found. In contrast to volcanically active regions, magma accumulation in the study area takes place at the crust-mantle boundary and is not yet accompanied by heat transfer to the surface. Likewise, reactive magma-derived components are absent in the degassing fluids. The area of investigation has the potential to be a natural laboratory for fundamental studies of active geodynamic processes. The results of our fluid monitoring, including the stunning observation of mantle-derived free fluids marked by 3He/4He ratios within the subcontinental mantle range, are supported by geophysical findings from seismic studies and geologic indications.
ID 839
dauerhafte UFZ-Verlinkung
Bräuer, K., Kämpf, H., Niedermann, S., Strauch, G., Tesař, J. (2008):
Natural laboratory NW Bohemia: comprehensive fluid studies between 1992 and 2005 used to trace geodynamic processes
Geochem. Geophys. Geosyst. 9 (4), Q04018