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' IV. GEOTECHNICAL DATA COLLECTION SUMMARY <br /> ' 4.1 General <br /> During 1997, no special detailed geotechnical data collection was necessary for either <br /> ' localized failure areas or highwalls excavated at slope angles steeper than default slope <br /> angles as neither occurred. General observations were made in the active mining areas <br /> in the Central Quarry, and in the North Quarry, but no detailed data collection was <br /> required or performed for interim slopes there, in accordance with permit conditions. <br /> Geologic mapping of new final highwalls was performed at the 5th and 6th highwalls <br /> ' (from the top-of-slope) at the East Highwall of the Central Quarry. In addition, the <br /> optical survey of surface survey monitor points in and around the repaired failure area in <br /> the East Highwall of the Central Quarry, reported on in the 1996 Annual Report, <br /> continued in 1997. CAMAS also collected mineralogical data on a localized area of <br /> high specific gravity ("heavy") rock encountered in the floor of the Central Quarry for <br /> operational purposes. <br /> During 1997, excavation in the Central and the North Quarries did not exceed any <br /> conditions which would require reevaluation of stability of the cut slopes. Mining in the <br /> Central Quarry was limited to excavation of benches at least 40 ft wide and highwalls 40 <br /> ft high or less at the south end, and to the planned bench configuration (50 to 60 ft wide <br /> benches and 40 ft high highwalls), or flatter, on the east side. Within the North Quarry, <br /> ' the 1997 highwalls and benches did not exceed an overall slope configuration of 1H:1V. <br /> CAMAS and Haley & Aldrich have continued periodic observations of the temporary <br /> slopes in these areas although evaluations and reporting of slope stability and <br /> geotechnical data for temporary slopes of this configuration are not specifically required <br /> ' by conditions of the approved permit amendments. <br /> 4.2 East Highwall of the Central Quarry <br /> A. Geologic Mapping <br /> ' Geologic mapping data was collected for the 5th and 6th highwalls (from the <br /> top-of-slope) at the East Highwall of the Central Quarry. Joint orientation <br /> (strike and dip) data was measured at approximately 100 ft intervals or areas of <br /> ' structural interest for final highwall segments established there during 1997. <br /> Other mapping data and observations such as fault/shear zone locations, fold <br /> axis trends, and intrusive dike locations, as well,as notes about rock type and <br /> condition, were documented. This information is included on the topographic <br /> map included in Appendix A. <br /> B. Optical Survey <br /> CAMAS provided survey support of the investigation and repair of the localized <br /> failure in the East Highwall during 1996. Survey support continued during <br /> 1997 in the form of continued monitoring of the post-repair surface settlement <br /> ' 6 G:\PROJEC7S\20200\002\97ANNRPT.WPF <br />