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<br />2.0 SITE COIJDITIONS <br />2.1 MORPHOLOGY <br />The area of ttte proposed long-term lease is situated <br />within the Colorado Plateau, a part of the Rocky Mountain <br />system. T'he plateau at tklis location is characterized by <br />mountainous terrain, dissected by numerous, deeply incised <br />valleys and gulches, carrying permanent, ephemeral or <br />intermittent streams. <br />The lowest elevations of around 7,000 feet are <br />encountered at the southern boundary of the lease; the <br />highest elevations reach about 9,000 feet in the central and <br />north portion of the lease. <br />The area is underlain by the Mesaverde Formation; the <br />formation dips uniformly at several degrees to the norttl. <br />The southern part of the lease is formed by a relatively <br />steep slope forming the valley side of North Fork Gunnison <br />River. The slope is formed by numerous outcrops of more <br />resistant sandstones separated by flatter slopes underlain <br />by less resistant, slope-forming shales. <br />• The remaining slopes in the area are much flatter and <br />they rarely contain outcrops of Mesaverde rocks. They <br />frequently carry a significant cover of colluvial soils. The <br />colluvial soils in ttte area invariably contain a significant <br />amount of basaltic rocks in the form of angular or <br />subangular gravel and boulders. As there are no known <br />outcrops of similar rocks in the area, it appears that these <br />rocks were derived from old basaltic bodies that were later <br />removed by erosional processes. Important accumulations of <br />colluvial soils containing basaltic rocks were apparently <br />deposited under different climatic conditions with a much <br />higher precipitation than that of today. <br />Numerous landslides in the area are another sionificant <br />feature that has a strong influence on the morphology. !•iost <br />of these landslides are old and stable at present; there are <br />no evident reasons for their development. It is probable <br />that their origin dates back to different climatic <br />conditions with a high precipitation when increased moisture <br />content and possibly the occurrence of ground water in the <br />Mesaverde caused the development of the landslides. <br />• <br />Most of the landslides appear to be concentrated on the <br />east side of Stevens Gulch, althou.~h minor slides have been <br />1Gen C1fled e1SeWhare 1.1 the lease aced. ^iOCpho'_071ca11~, <br />- 6 - <br />