Laserfiche WebLink
4. Climate <br />The New Horizon Mine soil study area is located in an "ustic- aridic" soil moisture regime and a <br />"mesic" soil temperature regime (Hawn, 1987) <br />The mean annual precipitation ranges from 10 to 14 inches. Were it not for the presence of <br />irrigation waterthroughout most of the study area, the soils would have soil moisture deficits during <br />the growing season as a result of the quantity and distribution of precipitation. Periods of peak <br />precipitation occur in the spring and early summer months. <br />Mean annual air temperature is about 46 to 48 degrees F. The average frost -free period is about <br />130 days. Additional climatological data is contained in Section 2.04.8 of this permit application <br />5. Geology <br />Adetailed discussion of the New Horizon geology is presented in Section 2.04.6 of this application. <br />Appropriate sections are summarized in the following text. The Nucla Syncline (San Miguel <br />Syncline) is a northwest trending geologic structure which contains the coal reserves of the <br />study area. This shallow, broad syncline is a simple fold with gently dipping flanks. <br />The Cretaceous -age Dakota Sandstone is the youngest formation found in the study area, with the <br />exception of Quaternary deposits. The overlying upper Cretaceous Mancos shale (a soft, <br />homogeneous, dark -gray fissile rock) is not found in the study area. The Dakota consists primarily <br />of resistant yellowish to gray, fissile sandstone, and conglomeratic sandstones interbedded with <br />dark gray carbonaceous shales, impure coal, and a basal conglomerate. It forms resistant but thin <br />sandstone ledges that are scattered throughout the study area. These ledges are often exposed <br />at the surface or are encountered within a few feet of the surface. <br />The deposits of Quaternary age consist of wind deposited material, streamlain alluvium, and local <br />slopewash. Deposits of a light -red sandy loam and loam loessial material mantle the nearly flat <br />mesa -like surface on the west side of the study area. <br />Revised September 2010 (PR 06) 2.04.9 -3 <br />