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19 Due to the number of samples to be tested, twelve 1:99 sedi- ment:water samples, a soil and weathered bedrock sample from each ~ W -.....1 o basin, were analyzed for the purpose of deriving a function describ- ing the rate of solution of the soluble minerals. EC for the 12 samples were determined as follows: 1) the samples were air dried at room temperature; 2) the 1:99 sediment:water ratio was obtained by mixing 2 g of crushed and sieved material with 198 g of distilled water in 500 m ~ Erlenmeyer flasks; 3) the flasks were closed with stoppers to eliminate evaporation and then were shaken for eight hours on a hori- zontal IS-flask capacity shaker at 140-150 cycles per minute, during which time EC was recorded at 0.25, 0.5, I, 2, 4, 6, and 8 hours; 4) at each measurement 25 m~ of solution were poured into the EC meter cup and its temperature was recorded; and 5) EC in J.lmho/cm at 250C for each solution was recorded by a 'Lecto Mho Meter' (Lab-line Instruments, Inc.) after the instrument was calibrated to the temperature of each sample. The measurements for the 12 samples were plotted as EC versus time. Although EC values varied considerably, each sample had a similar-shaped plot. The best fitting curves for the individual plots were natural log functions and power functions, with power functions of the form Y = bXm having the best fit based on r2 values. The exponents of the power functions, which described the curve, were averaged in order that one equation could be applied to all of the samples, regardless of initial EC values. The power function was used to estimate the maximum EC for all of the samples by the following procedure: 1) all samples were mea- sured for EC after two hours of shaking time; 2) intercept "b" was