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cover rock. Approximately 40% of the formation is sand (<3/8"). For construction applications, <br /> cobble is crushed for concrete/asphalt rock and for road base. <br /> The geology of the surface of this area is documented by the Soil Conservation Service in the"Soil <br /> Survey of Chaffee-Lake Area, Colorado". The surfaces are made up of St, Elmo gravelly sandy <br /> loam (SeB & SeF) and Dominson gravelly sandy loam (DoD). The pit is mostly SeB which tend to <br /> have slopes 1-3%. These soil types are normally shallow over cobbly and gravelly material. These <br /> descriptions are consistent with overburden stripped during mining operations. <br /> Beneath the surface soils, the geology is recorded by the USGS in "Geologic Map of the Upper <br /> Arkansas River Valley Region, North-Central Colorado" which is a"Pamphlet to accompany <br /> Scientific Investigations Map 3382" by Karl S. Kellogg, Ralph R. Shroba, Chester A. Ruleman, <br /> Robert G. Bohannon, William C. McIntosh, Wayne R. Premo, Michael A. Cosca, Richard J. <br /> Moscati, and Theodore R. Brandt. 2017. <br /> Map 3382 and the report describe the main pit area as alluvial deposit of"Qgb - Outwash gravel of <br /> Bull Lake glaciation, undivided (late and middle Pleistocene)" and the lower pit as "Qpf-Younger <br /> flood gravel and channel deposits of Pinedale glaciation (late Pleistocene)". Qgb deposits are <br /> described as raising 25m above the river surface on average. Qgb averages 10m above the river on <br /> average. These estimates are consistent with local well drilling and exposed river bank erosion. <br /> Therefore, mining in both pits is expected to encounter cobbly material down to the river level <br /> which is approximately 70'below the current pit floors. <br />