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2005 Subsidence and Geologic Field Observations <br />Box Canyon, West Flatiron, Apache Rocks, <br />and South of Divide Mining Areas <br />This traverse goes above mined longwall panels 13 and 13A in colluvium, weathered bedrock, <br />and some outcrops of the Barren Member of the Mesaverde Formation. The overburden depth to <br />the B-Seam varies from 1,200 to 1,350 feet. <br />No subsidence features were observed, except a small crack in bedrocks above mined longwall <br />panel 13 in 1,300 feet of overburden. This crack, which was the larger of two cracks in 2004 <br />(Location 14, Dunrud 2004a), is now nearly completely sealed by weathering, erosion, and <br />deposition. It would easily be missed if one did not know where to look. <br />In summary the effects (cracks mostly) caused by longwall mining in the western part of the <br />Apache Rocks mining area are healed and sealed up to the point where these effects could not be <br />differentiated from naturally occurring fractures. <br />4.17.1 Location 14 <br />This point provides a very good overlook to observe and photograph the large landslide, located <br />south of Minnesota Reservoir in the South of Divide mining area (Figure 15). The coordinates of <br />Location 14 is 286,654m E, 4,307,763m N (UTM, NAD 1983, circle of error: 3 to 6 m). Many <br />of the observations of the landslide are included in the caption of Figure 15. <br />The upper part of the landslide, which extends southward to the bedrock outcrops, is the most <br />stable part of the slide. The average slope on this part of the slide is about 20 degrees (as <br />measured from the USGS 7.5-minute quadrangle map). The lower, steeper, and more active part <br />of the slide is located north of, and out of the area of mining influence, of longwall panel 9 <br />(Map 3, Figure 15). <br />831-032.710 Wright Water Engineers, Inc. Page 32 <br />November 2005 <br />