APPLICATION OF ANALYTICAL METHODS FOR TRACE ELEMENTS IN GEOTHERMAL WATERS
In the present work, only cyclic hydrothermal systems are discussed; in particular, three thermal stations in the Vosges area. The temperature of the thermal waters at the emergence ranges from 33 to 70 degrees C. The water, which is meteoric in origin, infiltrates to deep levels where it is heated for a relatively long period (at least 30 years). In the area studied, the geothermal gradient is rather high (1 degrees C per 20 m), which may explain the relatively high temperature of these waters. In depth, the waters get their typical chemical composition by interaction with the surrounding (aquifer) granites. During their upward movement, they cool and some of them become mixed with cold subsurface and/or surface waters. The Plombies-les-Bains thermal sources (I-VII) are characterized by a low total mineralization. By means of the soluble elements and via isotope measurements, the mixing problem could be solved for these springs. The Bains-les-Bains springs (IX-XII) have the same total mineralization as those of Plombieres, but have a somewhat higher temperature at depth (150-160 degrees C). They may be considered to have a common second reservoir in the Triassic layers. They reach their final chemical composition by dilution with infiltrational water and by dissolution processes in the upper formations. For the Bourbonne-les-Bains thermal waters (XIV-XVI), the main reservoir is situated in sedimentary layers. These waters are characterized by a high total mineralization and contain certain elements in high concentrations indicating the presence of evaporite-like formations. Their temperature in depth is estimated to be at least 60 degrees C.
Bibliographic Reference: EUR 8871 EN (1983) MF, 153 P., BFR 240, BLOW-UP COPY BFR 765, EUROFFICE, LUXEMBOURG, POB 1003
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Record Number: 1989122021700 / Last updated on: 1987-01-01
Available languages: en