The geochemistry of some carbonate ground waters in central Pennsylvania
Files
Download Full Text
Publication Date
10-1-1971
Publication Title
Geochimica et Cosmochimica Acta
Volume Number
35
Issue Number
10
Abstract
The field pH and content of Ca2+, Mg2+, HCO3−, dissolved oxygen and other aqueous species have been measured in 29 spring waters and 29 well waters in folded and faulted Paleozoic carbonate rocks near State College, Pennsylvania. Most of the springs issue from limestone; most of the well waters are pumped from dolomite. Average specific conductances of the spring and well waters were 347 and , respectively, with polluted well waters having conductances as high as. Molar ratios as low as 0.6 in the well waters have resulted from incongruent solution of dolomite. Theoretical treatment of relationships between PCO2, pH and HCO3− content shows that solution of calcite or dolomite by undersaturated waters leads to increases in both pH and HCO3− content. This relation is approximately obeyed by the spring waters at an average CO2 pressure of 10−2.2 atm. In contrast, solution or precipitation of carbonates by waters near saturation with respect to them, results in inverse relationships of pH and HCO3−; a behavior closely obeyed by the well waters which have CO2 pressures up to 10−1.6 atm. Computer calculation of ground water saturation with calcite and dolomite at ground water temperatures (8–14°C) was made using remeasured solubility product data for calcite, and considering the effect of CaSO40, MgSO40 and MgHCO3+ ion pairs. Within the uncertainty of the chemical analyses and thermochemical data, 12 well waters and 3 spring waters were saturated with calcite, whereas 7 well waters and 3 spring waters were saturated with dolomite. None of the ground waters significantly exceeded saturation with respect to either carbonate.
Keywords
Carbonate rocks, Groundwater, Springs, Geochemistry, Hydrogeology
Document Type
Article
Digital Object Identifier (DOI)
https://doi.org/10.1016/0016-7037(71)90019-6
Language
English
Recommended Citation
Langmuir, Donald, "The geochemistry of some carbonate ground waters in central Pennsylvania" (1971). KIP Articles. 8381.
https://digitalcommons.usf.edu/kip_articles/8381
