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According to the text of Exhibit 6-l, the site specific geology map was `Based on <br />• information from Watec, Inc. (1981), Tweto (1976), and Golder Associates (1990)." <br />Apparently these reference sources were used to map those elements of geology other <br />than landslides shown on the map. In 1994 Bruce Stover, DMG, presumably added the <br />landslide information from an interpretation of aerial photographs that is summed up in <br />the map text (SCC, 1995). <br />"The following map units aze based on a photo and topographic interpretive study <br />completed by Stover (1994). These map units will be verified by field analysis. <br />Qols -Quaternary Age Deposits. Unconsolidated older surficial landslide <br />deposits. <br />Qls - Quatemary Age Deposits. Unconsolidated younger surficial landslide <br />deposits. <br />Als -Quaternary Age Deposits. Unconsolidated active surficial landslide <br />deposits." <br />According to the text, for his work, Stover used USGS aerial photographs flown <br />in 1970. Neither the Watec, nor Golder Associates data were available for the present <br />investigation. A check of Tweto's publications was made and the only one published in <br />1976 was identified (Tweto, 1976)as a regional geologic map. This map is at the scale <br />1:250,000 (3.95 miles per inch), and no landslide deposits were mapped within or neaz <br />the Yoast Mine. <br />4.01 Photogeologic and Field Review <br />A photogeologic review was made ofblack-and-white (b-w) and natural color <br />photographs. The b-w photographs were reviewed on July lst and 2nd and the natural <br />C~ <br />