Chemical Evidence from Icelandic Geothermal Systems as Compared to Submarine Geothermal Systems

  • Hrefna Kristmannsdóttir
Part of the NATO Conference Series book series (NATOCS, volume 12)


The Reykjanes geothermal system is the most interesting of the Icelandic geothermal areas for chemical comparison with submarine geothermal systems. The geothermal water at Reykjanes is seawater. Base temperatures in the Reykjanes geothermal system is considerably lower than the estimated temperatures of the submarine systems. In the Krafla geothermal system the base temperatures are almost as high as in the submarine geothermal systems but the geothermal water is of meteoric origin with low content of dissolved solids. Magmatic activity has strongly influenced the chemistry of the Krafla geothermal system.

In the Icelandic geothermal systems Mg and K are enriched at upper levels. Silica, Na, Ca, Fe and many of the trace elements have been mobilized, but a significant trend of depletion or increase has not been demonstrated. Mass fluxes by the rock alteration in the Reykjanes and Krafla area appear to be generally less than in hydrothermally altered metabasalts from the oceanic crust. This may partly be due to different sampling methods. The main reason for the difference is believed to be that all rock samples from the Icelandic areas are from the upflow zones in the geothermal system. A Mg enrichment and Ca depletion of the same magnitude as that demonstrated in submarine greenstones would rather be expected in the deep inflow zones of the Icelandic geothermal systems.


Basaltic Rock Alteration Zone Geothermal System Geothermal Field Geothermal Water 
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Copyright information

© Springer Science+Business Media New York 1983

Authors and Affiliations

  • Hrefna Kristmannsdóttir
    • 1
  1. 1.Department of Natural Heat, Geochemistry SectionNational Energy AuthorityGrensásvegur 9, 108 ReykjavíkIceland

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