Geothermal fluids mineralogy

Ragnarsdottir, K.V., Walther, J.V. and Amorsson, S. (1984) Description and interpretation of the composition of fluid and alteration mineralogy in the geothermal system, at Svartsengi, Iceland. Geochim. Cosmochim. Acta, 48, 1535-1553. 

Geophysical and mineralogical impacts of fluid injection in a geothermal system the Hot Fractured Rock site at Soultz-sous-Forets, France... 

This paper presents two aspects of the research project, namely the geophysical and the minera-logical evolution of the geothermal system as a direct consequence of fluid injection. It is a geological, mineralogical, petrophysical, and geochemical study of water-rock interactions at temperatures of up to, and higher than, 200 °C... 

This indicates that a general geothermal pattern has been established in the total column and that rapidly circulating warmer water has only local effects on the clay mineralogy. The mineralogy of these different types of semi-permeable rocks corresponds, on a depth-temperature basis, very closely with that found in pelitic shale rocks of other studies. It is likely therefore that high permeability gives a noticeably different set of chemical parameters (intensive variables) to a rock whereas medium to low permeability can be assimilated to a "closed" system where rock and fluid are effectively part of the same physicochemical unit. 

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