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<br />i <br />111 APP :ANP = 12.2:3.48 (for -100 mesh : -10 mesh material) <br />1!1 APP :ANP = 12.2:13.7 (for -100 mesh : -100 mesh material) <br />#3 APP :ANP = 4.7:1.4 (for -100 mesh : -10 mesh material) <br />N3 APP :ANP = 4.7:1.8 (for -100 mesh : -100 mesh material) <br />(A 10 mesh screen allows particles smaller than 2 mm (0.08 inches) to pass through the <br />mesh openings; a 100 mesh screen allows particles smaller than 0.15 mm (0.006 inches) <br />to pass. The finer grain size -100 mesh sample produced more acid than the -10 mesh <br />material. This should not be the case if total digestion of the acid pKOducing materials <br />was effected, as it should have been, by the testa <br />Organic sulfur and sulfate sulfur species were absent. (Organic sulfur was determined by <br />difference between total sulfur and sulfate sulfur; all such values were low, so reports of its presence <br />are considered moot.) Within analytical error, pyritic sulfur and total sulfur analyses were the same. <br />Thus, for conservatism, it was assumed that all of the sulfur in these samples is present as sulfide <br />sulfur, and capable of producing acid rock drainage. <br />Rock from one sample of the altered biotite gneiss has approximately similar quantities of acid <br />and base-producing minerals. Acid production rates could exceed base production rates, thus leading <br />to acid rock drainage. The other sample is a net acid producer with approximately 3 times more acid <br />producing material than base producing material. <br />B. Metals leachability - XRF and Batch Leach. <br />(From 1994 SRK report; 2 samples). <br />Copper concentration in one sample, as determined by XRF, is higher than what would be <br />expected of unmineralized sediments; its concentration (146 ppm compared with 55 ppm average crust) <br />coupled with the sulfur analysis is compatible with its presence as a sulfide mineral. Copper <br />concentration in the second sample exceeds crustal abundance by two times. <br />Arsenic detection limits were not low enough for environmental considerations. <br />No other regulated metals are elevated in these samples, relative to crustal averages. <br />C. Humidity Cell Tests. <br />(From 1994 SRK report; 2 samples}. <br />At detection levels of 10 to 50 ug/L, most of the analytes tested below drinking water levels. <br />Iron and manganese, however, tested above drinking water standards; these are secondary standards. <br />Selenium detection limits were not low enough to detect contamination at Ilre regulated level. <br />Selenium may need to be re-tested on these samples. <br />7 <br />