Geochemische und 13C/12C-isotopenchemische Untersuchung zur Herkunft der Kohlensäure in mineralhaltigen Wässern Nordhessens (Deutschland) |
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| Authors: | M Dietzel H Schwecke A Hirschfeld M Rhring M E Bttcher |
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| Institution: | M. Dietzel,H. Schwecke,A. Hirschfeld,M. Röhring,M. E. Böttcher |
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| Abstract: | Geochemical and 13C/12C-isotopical Investigation of Mineral Waters in Northern Hessia (Germany) and the Origin of their CO2 Content The dissolved carbonate originates from three sources: 1. biogenetic soil-CO2, 2. volcanic CO2 related to the evaporites of the Zechstein formation, and 3. carbonate derived from the dissolution of limestones and dolomites. Miocenic basaltic melts penetrated the evaporites of the Zechstein, and the related CO2 was trapped in the intra- and intergranulars of the salt minerals. Circulating meteoric waters dissolve the salt minerals releasing CO2 gas. Thus, the occurrence of basalt is related to the CO2 contents of the evaporites, and the dissolution of only small amounts of salts rich in CO2 may result in a high concentration of carbonic acid. In waters rich in carbonate, where volcanic CO2 dominates over the other two sources of carbon, a δ13C-value of “salt-CO2” of about –1‰ (PDB) is obtained. Water with less dissolved carbonate species have smaller quantities of salt-CO2 down to about 20%. |
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| Keywords: | Carbonic Acid Intergranular CO2 Dissolution of Calcite and Dolomite Isotopic Fractionation of 13C/12C and 18O/16O 34S/32S-signature |
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