Water chemistry. The Jarina WPA site exhibits "oligosaline" 

 magnesium-sulfate water chemistry. Water column trace element and 

 nutrient concentrations are comparable to regionally and 

 hydrologically similar sites. Mineral phase equilibrium 

 calculations indicate the water column is supersaturated with 

 carbonate phases and essentially in equilibrium with gypsum. 

 Calcareous crusts were observed riming littoral sediments; 

 authigenic gypsum was not observed. The magnesium-sulfate 

 composition and high gypsum saturation in a site of moderate 

 salinity are unusual within the DHES sample set. 



A seep discharging from Cretaceous sandstone of unknown formation 

 in a neighboring lake basin is proportionately much higher in 

 sodium and lower in total dissolved solids. 



Chemical history. No chemical data predating the DHES sampling of 

 this site are known. Conductivity measurements from August of 1994 

 are approximately 33% higher than during the site inventory 

 sampling in June of 1994. Substantially increased lake volume and 

 regular surface outflow in the past can be inferred from erosional 

 shoreline features. Salinity would be expected to be much lower 

 under such hydrologic conditions. 



Sediments. Boron, iron, nickel, selenium and zinc concentrations 

 are near the upper extreme for regionally and hydrologically 

 similar sample sites. Boron, nickel, zinc, arsenic and selenium 

 exceed regional mean soil concentrations by factors of 2 to 5, with 

 boron exhibiting the highest relative enrichment relative to 

 regional values. 



