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Geology <br />• A detailed 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 Migel Syncline) <br />is a northwest trending geologic structure which contains the coal reserves of the study area. This <br />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-grayfissile rock) is not found in the study area. The Dakota consists primarily of <br />resistant yellowish to gray, fissile sandstone, and conglomeratic sandstones interbedded with dark <br />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 at <br />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 mesa- <br />like surface on the west side of the study area. <br />• Soils and Geomorphology -f 988 <br />The study area occupies the part of the gently sloping western portion of "First Park," an irrigated area <br />adjacent to Nucla on the east, south, and west. The study area is shown in Map 2.04.9-1. The ephemeral <br />drainages generally cross the study area from northeastto southwest. Numerous small man made ponds <br />have been created along many of these drainages. Calamity Draw flows from east to west along the <br />southern border of the study area. Sewage lagoons for the town of Nucla are located adjacent to Calamity <br />Draw. Tuttle Creek flows from east to west along the northern border of the study area. Many of the <br />irrigation ditches which cross the study area empty into Calamity Draw and Tuttle Creek. <br />Aquolls and Aquepts soils were found primarily as a resuR of flood irrigation accumulating in the drainages. <br />These soils have characteristics indicating they are wet throughout most of the soil profile for most of the <br />year. <br />• (REVISED 2/00) 2.04.9-3 <br />