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ATTACf1~1ENT 6 <br />• <br />layers in ,various holes) and deposit the materials in essentially the reverse <br />order of their original state. Grading and transfer of the spoil material will <br />cause a considerable degree of mixing. Generally, the overburden up to 50 feet <br />above the coal seam will be mixed and exposed on the surface of the spoils. In <br />some cases mixing may prove beneficial where a layer of overburden with favorable <br />chemical and physical properties can be used to dilute a layer that exhibits <br />undesirable properties. <br />3.1 Emission spectographic scans of core samples <br />Percentage estimates of various elements detected are shown in tables 2A, <br />2B, and 2C for each panel. The purpose in obtaining these data is to learn <br />whether excessive, or possibly toxic, concentrations of elements might be present <br />in the overburden which could lead to problems in revegetaticn and in the quality -- <br />of the vegetation as food for animals. <br />In order to assess the significance of percentage estimates of elements, <br />comparisons were made with the mean elementary composition of shales, sand- <br />stones, and soils in which a range of values were shown (Bowen, H.J.M. 1966. <br />Trace Elements in Biochemistry, pp. 17-18;39. Academic Press, H.Y.) Boron, <br />a possible toxic element for plants, did not exceed the range of values for soils <br />or the mean value for sediments in any of the samples. Copper and zinc exceeded <br />the mean values for sediments and the range of values for soils in many of the <br />samples. Potassium was always lower than the mean values for sediments. In a <br />number of samples, magnesium was lower than the mean values for sediments and <br />soils. <br />- The extractable potassium and zinc (tables 3A, 3B and 3C) indicates more <br />accurately the effect of these nutrients on plant growth. These data do not <br />indicate any problems will be expected with potassium or zinc, and it is unlikely <br />that copper or magnesium will cause any problems. <br />3.2 Chemical properties <br />These values are shown in tables 3A, 3B, and 3C. <br />3.21 pH <br />The overburden in this area exhibits normal to high pH values. A high <br />pH usually indicates a high exchangeable sodium percentage (ESP). If the pH <br />is 8.5 or above in water this result indicates an undesirable soluble carbonate <br />content, a low solubility of calcium salts, possibly a nutritional imbalance Eor <br />plants, and an ESP of 15 or more. If the high pH is caused by soluble carbonates, <br />[he pH should decrease upon weathering because C02 will react with the carbonates. <br />When this result occurred in a layer from a given drill hole (table 6) the high <br />initial pH is not considered a hazard. Using this criteria, none of the overbur- <br />den samples in the West Panel would be expected [o cause problems from a high pH. <br />The overburden in the East Panel has some problems connected with high <br />pH values. Samples from holes CR 219 and CR 221 have an overburden with normal <br />pH values. Samoles from the remaining three holes (Cr 220, 222, and 223) show <br />pH values that indicate problems in managing and using the overburden. Coal <br />layers were not found in hole CR 224. The high pH values were associated with <br />ESP values greater than 15 and a high clay content. Witli the exception of CR <br />'~ 223, the overburden with high pH values occurs at the lower elevations and nor- <br />thern section of this panel. In hole CR 220 a layer (161' - 172') with a high <br />11 <br />