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<br />fJ033:~5 <br /> <br />James M. Soule of the CGS, with the cooperation and support of Robert K, <br />Barrett and John Post of CDOH, was given this study assignment in mid-A~ril, <br />1985, Office work began immediately and field study of the Meadow Mountain <br />landslide began on May 6, 1985, <br /> <br />The work plan for studying these landslides, after consultation between <br />CDOH and CGS personnel, consisted of the following: <br /> <br />1. General field reconnaissance of the landslides, initially in the <br />lower parts where the snow cover was less, and in the case of Meadow <br />Mountain, where road damage had already occurred, <br /> <br />2, Selection of points where, from field observations, interpretation <br />of aerial photographs, and as the work progressed, drill-hole data, <br />EDM points could be most usefully installed, Sequential monitoring <br />of EDM points could then be used to give quantitative measurement of <br />any downslope landslide movement, <br /> <br />3, During and after the drilling program, interpretation of the <br />drilling data to determine the nature of the landslide shear <br />surface(s), their depth. and in the case of the Meadow Mountain <br />landslide the rock unit involved from place to place, From the <br />drill-hole data, qualitative determination of the stratigraphic <br />level of landsliding (geologic bedrock formation), and generalized <br />estimates of the amount of material subject to possible movement. <br /> <br />) <br /> <br />:7':,:"-!:\r <br /> <br />.. <br /> <br />':~~,'!:":~:C <br /> <br />Installation of inclinometers in selected boreholes to supplement <br />data obtained from the EDM measurements. Three of the five holes at <br />the Dowds No, 1 landslide (the farthest upslope) were drilled and <br />completed to permit monitoring of 'water levels and comparison with <br />possible slope movements by inclinometers in the lower holes, <br /> <br />5. After evaluating the data obtained in 1.,2.,3" 4.. and noting the <br />locations of surface-water concentrations, areas of active earth <br />cracking, pressure bulges and ridges, and other diagnostic landslide <br />features, mapping of these features was to be done on high accuracy <br />base maps compiled from aerial photography made this year. At the <br />time of the writing of this report this part of the work has not <br />started because the base maps have not yet been received, <br />Intrasearch, Inc., of Denver, has been contracted to do thi s, <br />-.. <br /> <br />4. <br /> <br />6. It was decided' that the Dowds 2 slide was the least threatening and <br />that visual observations and subsequent detailed' ~urface mapping <br />would suffice for evaluating its slide potential. <br /> <br />- 3 - <br />