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Lincoln DeVore observations in the study <br />• area generally concurs with the description of the geologic <br />formations in the WESTEC report. Observations of surface out- <br />crops and the single exploration boring near this site indicates <br />the top of the basal sandstone sequence of the Mesa Verde Forma- <br />lion, known as the Rollins Sandstone, should be changed to ap- <br />proximately elevation contour 6080' to 6090'from 6050' assumed in <br />tF~e WESTEC report, using topography provided by Oxbow Carbon and <br />Minerals. <br />Lincoln DeVore field observations of <br />outcrops and very shallow test pits in the dry gully above the <br />proposed sediment pond indicate the thinly bedded sandstones may <br />be Cound as high as elevation 6090'. In addition, the weathered <br />• sandstones are exposed on the ground surface at and above a power <br />pole on a small ridge promontory at elevation 6070 and extending <br />up to appro~cimatel}~ 6080'. The <br />MESTEC, in the West Yard of the <br />Rollins sandstone at 18 feet below <br />mately ele~•ation 6082' to 608i'. <br />stone in the exploration boring is <br />sandstone or an eroded surface of <br />exploration boring placed by <br />Sanborn Mine encountered the <br />the ground surface or approxi- <br />It is not known if this sand- <br />the actual top of the Rollins <br />:he sandstone. <br />GENERAL AREA AND SITE GEOMORPHOLOGY <br />Site observations and a study of large <br />and small scale topography of this site indicates this north side <br />• of the Salle}• is possibly part of an ancient slope failure com- <br />3 <br />