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Within the North Quarry, the most recently-mined highwalls and benches did not exceed an overall slope configuration of 1H:1V. Cooley and Haley & Aldrich have continued evaluations and reporting of slope stability in this area although not specifically required by conditions of the approved permit Amendments. A summary of this data and evaluations are presented herein for the reader's use and in support of work anticipated for 1996. As [his area will be remined, no evaluation and reporting is required until mining reaches the final mined build-out. Geologic Mappine. Geologic mapping was conducted at the three areas of active mining during the week of 16 August 1995 by a geologist and a mining engineer from Cooley and CAMAS America, lnc., and during the week of 11 December 1995 by an engineer and geologist from Haley & Aldrich. Mapping activities included inspecting the relevant slopes from a distance to identify large-scale features and structures and to determine trends which may not be evident at a closer range. These observations were typically made from vantage points across the quarry from the wall being mapped. Detailed mapping focused on identifying and recording conditions and individual features of each highwall. Included in the mapping was identification, measurement, and documentation of the quality and strength of the parent rock material; the strike and dip of persistent joint sets; the joint frequency; and joint conditions exposed in the highwalls. Results of the geologic mapping are presented in Appendix A in a series of highwall sketch maps portraying prominent features. The maps show foliation joint and other joint set strike and dip data, dike and shear zone nature and location information, and other relevant geotechnical data on rock type, joint characteristics, and ground water seeps. The joint set data are also summarized in stereonet format in Attachment B. GEOTECHNICAL DATA ANALYSIS Results of [he geologic mapping were used to review rock slope stability in each of the three areas. Reviews were conducted to check that observed conditions were consistent with the conditions assumed during design and used as [he basis of the Observational Method presented in Mine Plan Amendments Nos. 3 and 4 and discussed previously herein. Two conditions were previously analyzed during design, and used as the baseline for further evaluations; "competent rock" representing the majority of expected conditions and "poor rock" representing localized areas of shearing, weathering or adverse jointing. Typical in-situ rock mass characteristics for each of these baseline conditions and the corresponding strength envelopes and calculated safety factors are presented in Permit Amendment No. 3, Section 4- 04. To follow are the descriptions of ground conditions observed relative to the baseline conditions for each of the three areas worked during 1995. South End of Central Quarry. Results of the observations at the south end of the Central Quarry revealed [he following general conditions: The parent rock material is typically weak and is estimated to have an unconfined strength less than 15,000 psi. 2. The rock mass structure is highly fractured and contorted with little consistent pattern. The primary joint set is along foliation of the gneiss and schist rock attd on average 3 c:~ozao~aowaa.:ao