and iron concentrations were also high, with most higher 

 concentrations reported from sites of known contamination with 

 mining and mineral processing waste. Most other trace element 

 concentrations were below reporting limits. 



Chemical history. Previous chemical data from the White Lake basin 

 were collected on shallow ground-water samples drawn from beneath 

 the playa surface or from peripheral ponds known as East and West 

 White Lakes, which exhibit much more dilute water chemistry. The 

 shallow ground-water samples (collected in 1990 at a time of little 

 or no surface water in the playa) were more concentrated than the 

 WET79 sample; density gradients may maintain salinity contrasts 

 between the shallow ground water brine and surface water during 

 periods of inundation. Generally, White Lake probably exhibits 

 substantial salinity variation but remains hypersaline in 

 character. 



Sediments. Authigenic sediments in the White Lake basin are 

 dominated by sodium sulfate salts not represented in the DHES 

 sediment analysis. Relatively high calcium and magnesium 

 concentrations may reflect both detrital sediments and minor 

 authigenic carbonate precipitation. 



The extractable arsenic concentration was the highest for any 

 sample site not impacted by mining wastes, and exceeded all other 

 Great Plains sites by a wide margin. The boron concentration 

 reported also ranks relatively high. Extractable iron, vanadium 

 and zinc concentrations were relatively low, and most other trace 

 element concentrations were below reporting limits. Extractable 

 arsenic and boron concentrations exceeded geometric mean soil 

 concentrations for the western United States by factors of 13.9 and 

 2.4, respectively. 



