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south. Where present, kinematic indicators suggest dip-slip movement and little to no <br />shear (Robeck 2005). <br />Figure 4 presents an east-west geologic cross section near the study area. The major <br />units present are representative of the Cretaceous Age Lower Mesa Verde Formation in <br />this area and include the Rollins Sandstone, the C-Sandstone (locally referred to as Bowie <br />Sandstone or Upper Marine Sandstone), coal seams A through Upper D. Horizontally <br />bedded mudstone and siltstone sequences, together with the cross-bedded to laminar <br />bedded fluvial sandstone channels, are also present, but shown as undifferentiated on the <br />cross section. The alluvial valley fill is believed to be Quaternary in age and is composed <br />of Tertiary age igneous boulders, cobbles, and gravel. <br />The coal seams and the Rollins and C sandstones are the only truly tabular <br />sedimentary bodies in the section. The two sandstone bodies are even more laterally <br />continuous than the thinner coal seams. Because of strength and lateral persistency, these <br />two marine sandstone bodies have by far the best characteristics for bearing and <br />distributing loads. The C-Sandstone is approximately 50 ft thick. <br />Figures 5 presents detailed geotechnical logs for DD-D9X43-37 and include <br />lithology, structure, and material properties near both the Upper B and Lower B seams. <br />The structural log indicates the location of geologic discontinuities (including both <br />natural and drilling-induced fractures). Much additional data regarding the condition of <br />discontinuities (including roughness, aperture, and spacing) were collected, but were <br />excluded from these logs for clarity. <br />As illustrated in figure 5, the immediate roof above the Upper B Seam has medium-to <br />high-strength that ranges from 14,600 to 19,000 psi. Strength increases into the roof, <br />reaching a maximum of 22,000 psi. With a Young's modulus of approximately 2,600,000 <br />psi, the immediate roof falls into low modulus category. <br />• <br />Maleki Technologies, lnc. Page 15 <br />