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<br /> <br />2. The performance of slopes cut at varying angles; <br />3. The location, frequency, length, persistence, orientation, dip, and in-filling (if any) <br />of all significant fractures in the highwall materials; <br />4. The location and nature of water appearing on highwall faces (if any); and <br />5. Location and nature of rock mass failure (if any) appearing on the Mine highwall <br />faces. <br />Using this information, CC&V has prepared, and continues to update, an evaluation of the <br />geologic "structure" of the area. This update consists of mapping the orientation and continuity <br />of fractures or joints and projecting these data onto the current, and future, Mine highwalls. <br />The fracture and projected highwall orientations are then analyzed to evaluate the factor of safety <br />of the current and future highwalls. <br />Mine "Structures" <br />The original slope design was based on joint mapping, from four shallow surface openings in <br />the vicinity of the Mine, and on the results of four oriented core holes drilled in the deposit <br />(Lightwood and Nicholas (Call and Nicholas), 1993. See Appendix 3 of Volume IV of <br />Amendment Number 6 Application). Those data indicated several joint sets, as follows: <br />Strike NNW; dip 60-90 degrees to east and west; dominant <br />Strike NW; dip 4-70 degrees to NW; strong <br />Strike horizontal; dip 10-30 degrees to SW; subordinate <br />Strike approximately NNE; dip 20-50 degrees to ESE <br />The mapping of actual highwall joint information, which has been ongoing since the inception <br />of mining, has refined these joints sets as follows: <br />North area <br />Strike north-south; dip nearly vertical; dominant <br />Strike east-west; dip 45 degrees to north; subordinate <br />South area <br />Strike north-south; dip nearly vertical; dominant <br />Strike varied; dip nearly vertical; subordinate <br />Strike N15°W; dip 60 degrees east; minor <br />In summary, the Cresson Mine rock mass has one major joint set which dips essentially <br />vertically, and which is oriented approximately north-south. This is also the same orientation <br />as the structural features (joints and dikes) observed in the highwalls. Throughout the Mine <br />there are numerous small fractures with other orientations, which are also predominantly steeply <br />dipping, and rarely extend more than one bench. There are also flat to gently-dipping joint sets. <br />2 <br />