PERMFILE42013 - Laserfiche WebLink

Home Browse Search

Subsidence Evaluation For Exhibit 608 South of Divide Mining Area Page 19 • 2. Box Canyon mining azea (no mining had occurred when these landslides were last observed): a. Landslide and rockfall area located above mined longwall panel 22 and un-mined longwall pane123 in the NE'/< of Section 22 and the NW'/4 of Section 23. b. Landslide and rockfall area located above the southeastern part of un-mined longwall pane121 in the NE'/a of Section 23. c. Landslide azea located above un-mined longwall panels 19, 20, and 21, on the east side of Box Canyon in the W%z of Section 14. d. Landslide and rockfall area located above un-mined longwall panel 19 on the west side of Box Canyon in the approximate center of Section 14. e. Landslide located above un-mined longwall panel 18 on the east side of Box Canyon in the NW'/, of Sectionl4. f. Extensive landslide azea located south of the North Fork of the Gunnison River along State Highway 133 in the S''/z of Sections 10, 11, and 12 andthe N11/z of Section 15. 3. South of Divide mining azea (Map 1): • a. An extensive landslide is located south of Minnesota Reservoir above the northern part of projected longwall panel E9, in the N''/z of Section 32, Township 13 South, Range 90 West (Dunrud 1989). Overburden depth to the E Seam ranges from 500 to 550 feet. The average slope of the slide is roughly 20 percent. The landslide contains more cracks and scarps in the upper part and more depressions and bulges in the lower part than were present in the eazly 1960s (based on image data from July 1963 aerial photographs). Based on a stereographic review of July 2004 vertical aerial photographs, renewed activity occurred locally in western part of the landslide areas north and south of Dry Fork during wet periods in the 1980s (1984 to 1987} and the mid 1990s (1994-1996). The Dry Fork road was taken out one half-mile west of the Minnesota Reservoir dam by this renewed movement in 1987 (Map 1). b. Landslide located neaz the north shore of Minnesota Reservoir in the SW'/a of Section 29. This slide is located on the border between the Apache Rocks and South of Divide mining aeeas. c. landslide azea located on the Dry Fork road in the approximate center of Section 31, Township 13 South, Range 90 West. Two small landslides are located to the southeast in the SE'/< of Section 31 and the SW'/a of Section 32. 831-032.620 Wright Water Engineers, Inc.