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• As shown by these figures, the landslide deposits aze up to 148 feet thick. The thickest part occurs in the lower bench or northern part of the ]andslide mass where the deposits directly overlie the 'B' seam. However, as shown in Figure 7, a lobe of landslide deposits extends further upslope in the central part of the azea. In the upper or south part of the landslide mass, the base of sliding is not readily identifiable as it does not correspond to the 'B' seam. Little or no colluvium was recognized on the logs of borings penetrating this azea. It is likely that most of the landslide debris that was present has been removed by erosion over the centuries. Nature of Landslide Materials Borings through the lower bench part of the landslide penetrated a heterogeneous range of materials including sands, boulders, clays and coal fragments. This material is interpreted as landslide debris which has travelled a considerable distance from its source, with consequent mixing of blocks of material from a range of strata. Borings through the upper part of the ]andslide generally penetrated sedimentary bedrock from • near the surface. This material was not identified as being part of the landslide. Neaz the surface, this rock mass may have been disturbed by minor downslope movements which would not be evident from the drill cuttings. Cross-sections SN3, SN4, and SNS through the center of the area show good correlations and consistent dips of strata between borings. This indicates that there has been no major deep-seated sliding. Current Instability There is no evidence of current or recent instability on the lower, bench portion of the landslide. In fact, the lack of any surface evidence of past movement indicates that this area has been stable for a long period. Scarps up to 12 feet high aze present in the upper, steeper south part of the landslide mass as shown on Figure 1. These scarps indicate recent movement. The largest of these scarps aze evident on both 1974 and 1992 aerial photographs. This indicates that sliding is occurring slowly -probably less then one foot per year of overall downslope movement. The fact that sliding is still occurring is evidenced by fresh cracks, unvegetated scarps, and toppled vegetation associated with recent movement. Hummocky ground, which is indicative of recent but not • -10- 0: \Of f\30\JPTUR00-Rpt.lk!