Laserfiche WebLink
2.2 POTENTIAL AVF WITHIN THE STUDY AREA <br />Two potential AVF areas were identified in stipu- <br />lation 20 to the Permit to Mine ~~ C-038-81 (Plate 1). Alluvial <br />deposits are found along either side of North Fork Gunnison <br />River. The alluvium is bordered by pediment and colluvium <br />deposits derived from upland sources (Plate 2). <br />The upper portions of Stevens Gulch contain several flat- <br />bottomed valley forms which could qualify as AVF areas. Only <br />one of these areas is within the study area, where a potential <br />AVF was identified at the CWI well field site. This area ex- <br />tends upstream from the well field to the.adjoining property <br />and is bordered on all sides by colluvial soils and hillslope <br />debris. It covers a total area of approximately 20 acres. All <br />other possible AVF areas in Stevens Gulch are upstream of the <br />well -field, and would in no way be affected by present mine <br />• operations. No future surface disturbance or facilities are anti- <br />cipated in these locations. (Plate 2). <br />3.0 SITE CONDITIONS <br />3.1. GEOLOGY <br />The area surrounding the Orchard Valley Mine is under- <br />lain by flat-lying Cretaceous and Tertiary sedimentary rocks, <br />locally intruded by Tertiary igneous rocks. The Mesaverde <br />Formation and the Mancos Shale are the predominant units. Both <br />units dip approximately 2 to 5 degrees to the north-northeast. <br />The Mesaverde Formation, of Upper Cretaceous Age, con- <br />~~ <br />- 5 - <br />GEO•HYDRO CONSULTING, INC. <br />