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continue to be intercepted near the northwest comer. Currently it is <br />anticipated that the increased exposure of the broken fault material will <br />have minimal impact on the overall wall stability. <br />6) During the mapping exercises for the west wall of the main pit, foliation joint <br />surfaces were found to contain seams of greenish-gray material (Photo 7). <br />Seams of similar material were observed on the east and south faces of the <br />advancing benches in the main pit as well. The seams ranged from'/:" to 3" <br />in thickness and were continuous over the visible distances of the <br />discontinuities. The seam material is readily friable and slakes rapidly upon <br />immersion in water. A sample of the seam material was submitted to a <br />testing laboratory for soil classification, gradation analysis, and Atterberg <br />limits determination. The results of the laboratory tests are included in <br />Appenidix C. To summarize, the sample contains a significant amount of <br />fines (48.9% passing the #200 sieve), plots as a clay of low plasticity (CL) <br />on the Atterberg Plasticity Chart, and classifies as a clayey sand (SC) per <br />the Unified Soil Classification System (USCS). <br />It is believed that the seam material may reduce the frictional resistance of <br />the foliation joints to sliding. L&A recommends collecting additional <br />samples of this seam material and performing additional laboratory testing <br />(such as petrographic analysis, slake durability, swell tests, and additional <br />gradation and Atterberg limits) to better define the physical and engineering <br />properties of the material. As recommended in the past, core samples <br />obtained from a boring would enable additional testing of the joint surfaces <br />to obtain a better estimate of the effective frictional resistance to sliding <br />along the joint surfaces. <br />7) Raveling conditions resulting from rock fragmentation during blasting and <br />subsequent freeze/thaw conditions exist along each wall in the quarry, but <br />' 2002 Spec-Agg Annual Report Page 9 <br />