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<br />• 16 <br />The absence of substantial information on associations of the trace metals with <br />pyrite or other more abundant species is not surprising based on the low level of <br />these trace elements in the Cresson material. <br />While there appears to be some concern relating to the lack of detection of <br />carbonate minerals in most of the samples tested, there is evidence for this mineral <br />in two samples, both from the sulfide zone, and its apparent absence in other <br />samples can be explained by samples viewed, by its relatively low concentration, and <br />by proposed reactions which may have depleted carbonate minerals in a particular <br />horizon. <br />in summary, 1 view the Mineralogic analyses as a carefully executed set of tests which <br />have given more confidence to the assignment of mineral assemblages present in the <br />Cresson overburden. The results are generaNy consistent with primary mineral <br />components and weathering reaction byproducts which have been postulated for the <br />Cresson project in this and earlier reports. While this type of data does not directly <br />address the issues of acid development and metals mobilization from these materials, it <br />does give us more confidence in projecting how materials with different sulfur levels might <br />be expected to react in terms of these environmentally significant factors. If later dynamic <br />tests of acid generation and metals mobilization present us with unexpected or apparently <br />anomalous results, we may revisit these Mineralogic analyses to see if they provide clues <br />to an answer for these results. <br />Maior and Trace Element Analyses on Ilumidity Cell Test Materials <br />The test data in this area support the contention that the samples are in fact low inmost <br />trace metals and have sulfur contents that span a reasonable range from 0.02 to 1.86%. <br />None of the samples reported have as high a sulfur level as the highest of the materials <br />used for humidity cell testing or reported in the set of 37 samples earlier in the report. <br />The absence of this highest sulfur level material in this data set, however, does not appear <br />to compromise conclusions based on the reported data. <br />The relatively low levels of calcium and magnesium in the samples would suggest that any <br />calcite or dolomite in the materials is there in relatively low concentration. Loss on <br />ignition data, which could represent both water and thermally unstable carbonate or other <br />minerals loss or decomposition also is consistent with low levels of cazbonate <br />mineralization. <br />At the low levels which the trace metals are present, less than 100 ppm for nearly all <br />elements in nearly all samples, it is difficult to draw too many conclusions relative to the <br />likely association of these elements with, for example, sulfide sulfur and no such <br />conclusion is drawn in the report. <br />In summary, the data on major and trace elements in the tested humidity cell <br />samples show no unexpected results and would seem to support the proposition that <br />O[~t1..R951DEH <br />