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D Flock Logic <br />Consulting LLc <br />Memorandum <br />Date: 6 June 2014 <br />To: Jim Abshire <br />Bill Bear <br />Art Etter <br />Rock Logic Consulting <br />PO Box 544 • Cedaredge, CO 81413 <br />Phone: (435) 851 -9044 • rocklogicconsulting @gmail.com <br />Brad Lindsay • Consulting Geologist <br />From: Brad Lindsay <br />Subject: Spring 2014 Subsidence Crack Mapping <br />Field Survey <br />A thorough field survey above the northern approximately two thirds of the B- 141ongwall area was <br />conducted on May 5`h and 6`h 2014. The southern approximately one third portion of the B -14 panel <br />was checked in the fall of 2013. The mined B -14 panel runs north -south west of terror creek. Areas <br />of both mildly sloping terrain and steep topography overlie the panel. Traverses over the panel were <br />hiked to observe visual evidence of subsidence. Thick brush and steep slopes exist in the area. A <br />GPS unit was utilized in track mode to record the path of all traverses and locations of cracks <br />observed. Each new crack was photographed and the orientation, length, width, and vertical <br />displacement were measured. <br />Observations <br />Only three cracks were observed during this survey despite extensive hiking. All three cracks were in <br />the southern portion of the area surveyed. These cracks were observed in areas of scrub oak. No <br />cracks were observed within aspen stands. These results are similar to findings above the north half <br />of the adjacent B -13 panel. Two of the cracks run in a direction that parallels topography. The third <br />area is a small slump which occurred next to a road cut. Cracks over the B -10, B -11, B -12, and B -13 <br />panels continue to heal. <br />Files <br />Crack measurements and field notes are recorded in an Excel file (Subsidence Crack Mapping Spring <br />14.xls). The AutoCAD map ( Subsidence - Crack- Mayl4- source.dwg) was updated with the GPS track <br />and lengths, orientations, and locations of new cracks observed. Digital photos of the cracks <br />are attached. <br />