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<br />TABLE OF CONTENTS <br />Pane <br />1.0 SUMMARY OF MAJOR FINDINGS ................................................................................1 <br />2.0 OVERVIEW OF FIELD GEOLOGIC STUDIES JULY 12-15, 2004 AND OF PHOTO- <br />GEOLOGIC STUDIES AUGUST 8-15, 2004 ...................................................................4 <br />3.0 INTRODUCTION........ <br />4.0 MINING METHOD..... <br />.............5 <br />.............6 <br />5.0 GEOLOGIC FACTORS INFLUENCING SUBSIDENCE ..................................................8 <br />6.0 FIELD RECOGNITION OF SUBSIDENCE AND NON-SUBSIDENCE FEATURES IN <br />THE WEST ELK MINING AREA .....................................................................................9 <br />6.1 Subsidence Cracks and Compression Features .................................................................9 <br />6.2 Construction Cracks ..........................................................................................................10 <br />6.3 Desiccation Cracks ........................................................................................................... 10 <br />6.4 Pseudo Subsidence Cracks (Gravity-Induced Tension Cracks) .......................................11 <br />7.0 SUBSIDENCE PREDICTION BASED ON PAST LONGWALL MINING .......................12 <br />7.1 Vertical and Horizontal Displacement, Tilt, Curvature, and Horizontal Strain ...................12 <br />7.1.1 Maximum Vertical Displacement .......................................................................13 <br />7.1.2 Maximum Tilt .....................................................................................................14 <br />7.1.3 Maximum Horizontal Strain ...............................................................................14 <br />7.2 Maximum Projected Depths of Surface Cracks ................................................................15 <br />8.0 GEOLOGIC AND TOPOGRAPHIC OBSERVATIONS IN THE SOUTH OF DIVIDE <br />MINING AREA ..............................................................................................................19 <br />8.1 Field Location 1 .................................................................................................................19 <br />8.1.1 Field Observations .............................................................................................19 <br />8.1.2 Aerial Photo Observations of Landslides North and South of Minnesota <br />Reservoir ........................................................................................................................22 <br />8.1.3 Aerial Photo Observations of Rockfalls in the Minnesota Reservoir Area......... 25 <br />8.2 Field Location 2 .................................................................................................................25 <br />8.2.1 Aerial Photo Observations at Location 2 ........................................................... 28 <br />8.3 Aerial Photo Location 3 ..................................................................................................... 29 <br />