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.~ Several <br />based on the <br />results of <br />follloors: <br />important conclusions can, however, be made, <br />results of Junge's (1978) study and on the <br />our inspection. They can be summarized as <br />o It appears that the southern border of the proposed <br />lease comprises the most stable part of the area. There are <br />no known larger landslides or other serious stability <br />problems in this part. A few ;minor, old landslides of a <br />limited extent have been indicated by Junge in this part. <br />o Large and extensive landslides do exist in the <br />valleys of all tributaries of North Fork Gunnison River. The <br />largest landslides have developed on the east valley side of <br />Stevens Gulch. l+le believe that one of them dammed the <br />Stevens Gulch valley and created a large lake that was later <br />filled with alluvial deposits; the Stevens Gulch alluvium <br />that is used for the Cl4I well field is a result of such a <br />landslide. <br />o There are two groups of landslides within the lease <br />area: old landslides that probably developed during the <br />Pleistocene Period, under different climatic conditions <br />(much higher precipitation and runofF) and recent <br />landslides, whose deformation can be observed at the present <br />• time. <br />o The group of landslides identified by Junge belongs <br />to the Pleistocene, old landslides. All of them appear to be <br />stable under present climatic conditions. They frequently <br />feature a typical hummocky landslide topography; a few stock <br />ponds are located within the landslide areas. <br />o In addition to the old landslides, several recent <br />landslides have been identified during our field inspection <br />(see Plate 3). These landslides appear to be concentrated <br />along the east slopes of Roatcap Creek, the unnamed creek <br />between Orchard Valley Mine and the Farmers Mine and the <br />creek just below the Farmers Mine. These are recent <br />landslides; some of them apparently occurred during the <br />spring of 1983. Some of them are older, but renewed <br />deformations can be observed at present. The yardage of some <br />of these landslides is considerable. It appears that these <br />landslides are related to local unfavorable ground water <br />conditions. <br />o The areas of the recant landslides have been found <br />only on east slopes of the three tributaries; such slopes <br />are potentially uns*_able and addi^_ional sliding may occur <br />under unfavorable climatic conditions such as those of the <br />• <br />- 10 - <br />