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I. SUl'~tARY AND CONCLUSIONS <br />• In accord with Federal Coal Mine Operating Regulations <br />30 CFR, 211.10(c)(6)(xii), W. R. Grace undertook an extensive <br />study of nine drill logs and testing of interburden associated <br />with seven major seams and several lesser seams of coal at <br />Colowyo mine, Axial, Colorado. <br />Testing of the interburden has involved collection of <br />38 sample sections from drill hole 3-56 -G 13, their preparation <br />and extraction at two water-solids ratios--1:1 and saturation--and <br />analyses of the leachates for dissolved solids. This report, <br />Part I, pertains to 19 overburden samples associated with X seam <br />coal. The remaining 19 samples, below X seam, and their test <br />results will be reported shortly; analyses of leachates for <br />Part II are complete, but anomalies in the data require verifica- <br />tion. Consequently, the data for Part II have not been analyzed <br />for content or meaning. <br />• Interburden contained within the boundaries of Sections 2, <br />3 and 10 (Colowyo mine coordinates TR3, R93W) consists of <br />cyclic beds of shale, carbonaceous shale, sandstone and crevasse <br />splays. In general, the strata immediately above and beloca <br />each coal seam of drill core G-59 consist of shale or <br />carbonaceous shale. Seams X and A2 are an exception to this <br />generalization and the overburden is sandstone. The stratum <br />immediately overlaying E seam, the roof, is composed of 6" <br />of oystershell, extending several hundred yards in all directions <br />from drill hole 3-56-G13 (G-59). In the vicinity of drill <br />hole G-42, the F"seam roof is composed of a carbonate concretion. <br />The topsoil, A and B horizons, possesses greater water <br />saturation capacity than other portions of the interburden--~60% <br />water saturation percentage. Testing conclusively shows <br />1:1 extracts from the A and B horizon soils have a very loco <br />salinity and alkalinity, indicative of extensive leaching and <br />weathering in the past. Er:tracts from lower interburden sections <br />possess greater salt contents, indicative of less Leaching. <br />