known or inferred to dominate the surficial geology of the site. 

 Recent chemical sediments are also outside of the coding system 

 and are not recognized in these database fields. Where no 

 information regarding surficial deposit is available, this field 

 is left blank. 



Geologic units are specified at the lowest hierarchical level 

 supported by the available information, which varies between sites. 

 Thus a more general code (400BELT) may be used if a more specific 

 one (400WLLC) cannot be determined from the available information. 

 Where the wetland is known to be underlain by more than one 

 geologic unit, the field is coded for the hierarchically lowest 

 common stratigraphic division. For example, a wetland known to be 

 underlain by both the Two Medicine and Telegraph Creek Formations 

 (of the Montana Group) would be coded 211MNTN (the Montana Group). 

 Where the wetland is known to be underlain by geologic units of 

 different eras, the field is coded for the geologic unit having the 

 greater extent within the drainage basin of the wetland. 



Calpite . aragonite , dolomite and gypsum sattpratjom indices. 



Aqueous solution composition and saturation indices were calculated 

 using PCWATEQ, a DOS-driven version of the chemical equilibrium 

 program WATEQF. Since dissolved analyses were conducted only for 

 major components, no equilibrium calculations were performed for 

 phases involving iron or other trace constituents. As applied, 

 these solution equilibria are of interest mainly in identifying the 

 theoretical saturation status of major carbonate and sulfate 

 mineral phases. Analytical bicarbonate and carbonate 

 concentrations were used in the WATEQPC input (Alkalinity Option 

 2); field dissolved oxygen measurements were used for calculating 

 pE, and the Davies equation was used for all samples (including 

 highly saline sites.) 



