Chemical Weathering of Smectitic Sulphide-Mineral-Bearing Unconsolidated Surficial Sediments in South-Central Alberta, Canada

Autor: G. F. Huff
Rok vydání: 2014
Předmět:
Zdroj: Aquatic Geochemistry. 20:381-403
ISSN: 1573-1421
1380-6165
DOI: 10.1007/s10498-013-9223-6
Popis: This study used a mass-balance simulation approach in conjunction with geochemical, mineralogical, thermodynamic and isotopic constraints, to assess the origins of NaSO4(±HCO3) type groundwater and springwater associated with smectitic sulphide-mineral-bearing unconsolidated surficial sediments and the underlying Paskapoo Formation in south-central Alberta. Results indicate that alteration of albite to kaolinite and alteration of kaolinite to Na-smectite are the primary controls on dissolved Na and SiO2 concentrations in groundwater and springwater. Concentrations of dissolved Ca and Mg are controlled by reactions involving carbonate minerals and possibly cation exchange. Dissolved SO4 is generated primarily through oxidation of pyrite. Most H+ generated by oxidation of pyrite is consumed in aluminosilicate alteration reactions. The carbon isotopic composition of CO2 gas required in mass-balance simulations suggests the presence of an isotopically heterogeneous environment with respect to 13C. This apparent isotopic heterogeneity may result from the presence of varying fractions of atmospheric and microbially respired CO2.
Databáze: OpenAIRE
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