thumbnail

Correction of ground-water chemistry and carbon isotopic composition for effects of CO2 outgassing

Geochimica et Cosmochimica Acta

By:
, , and

Links

  • The Publications Warehouse does not have links to digital versions of this publication at this time
  • Download citation as: RIS

Abstract

Direct Pco2 measurements on water samples from several CO2-charged warm springs are significantly higher than Pco2 values calculated from field pH and alkalinity (and other constituents). In addition, calcite saturation indices calculated from field pH and solution composition indicated supersaturation in samples which, on the basis of hydrogeologic concepts, should be near saturation or undersaturated. We attribute these discrepancies to uncertainties in field pH, resulting from CO2 outgassing during pH measurement. Because samples for direct Pco2 measurement can be taken with minimal disturbance to the water chemistry, we have used the measured Pco2 to back calculate an estimate of the field pH and the carbon isotopic composition of the water before outgassing. By reconstructing water chemistry in this way, we find generally consistent grouping of ??13C, pH, and degree of calcite saturation in samples taken from the same source at different times, an observation which we expect based on our understanding of the hydrogeology and geochemistry of the ground-water systems. This suggests that for very careful geochemical work, particularly on ground-waters much above ambient temperature, Pco2 measurements may provide more information on the system and a better estimate of its state of saturation with respect to carbonate minerals than can field measurements of pH. ?? 1978.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Correction of ground-water chemistry and carbon isotopic composition for effects of CO2 outgassing
Series title:
Geochimica et Cosmochimica Acta
Volume
42
Issue:
12
Year Published:
1978
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Geochimica et Cosmochimica Acta
First page:
1799
Last page:
1807