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Dakota sandstone is the youngest formation found in the study area, excepting Quaternary <br />deposits. The Dakota formation consists primarily of resistant yellowish to gray fissile <br />sandstone, and conglomeratic sandstones interbedded with dark gray carbonaceous shales, <br />impure coal, and a basal conglomerate. It forms resistant but thin sandstone ledges that are <br />scattered throughout the study area. These ledges are often exposed at the surface or are <br />encountered within a few feet of the surface. Quaternary age deposits, which are also present <br />in the study area, consist of wind deposited material, stream Iain alluvium, and local slopewash. <br />See Section 2.04.6, Geology Description for a more detailed discussion of the geology for the <br />study and surrounding areas. <br />2.2 Soil - 1987 The dominant soils within the study area are the Barx, Progresso, Bond, <br />Bowdish, Lazear, Travessilla, and Pinon (sic) series. Also included are large areas of <br />Haplaquolls (no series names assigned). The Barx, Progresso, and Bond series are the <br />predominant cropland soils and were originally dominated by sagebrush -grassland native <br />vegetation prior to cultivation. The Barx series consists of deep well drained sandy loam soils <br />on flat to gently sloping uplands formed in alluvium derived from sandstone. The Bond and <br />Progresso series consist of shallow to moderately deep well drained sandy loam soils on <br />uplands formed in alluvium derived from sandstone. Mixed with the above soils are smaller <br />inclusions of Lazear and Bowdish sandy clay loams. These upland soils are shallow to <br />moderately deep, well drained, and were formed in residuum derived from sandstone and <br />interbedded shales. The Travessilla and Pinon channery sandy loam soils occur on uplands <br />that cannot be cropped or irrigated because of rock outcrops, shallow soils, and topography. <br />These areas have a sagebrush-grass/forb vegetation cover, but the original native vegetation <br />was dominated by pinyon -juniper with associated understory shrubs and herbaceous species. <br />The Travessilla and Pinon channery sandy loams are shallow to very shallow well drained soils <br />formed from sandstone. In terms of agriculture, the latter two soils are the poorest in the study <br />area. Other soils found on the study area include the Haplaquolls (no series name assigned). <br />These are poorly drained shallow to deep soils and range from silty clay loams to sandy loams. <br />They have formed in alluvium from recently deposited sediments in minor intermittent streams, <br />sloughs, flood plains, and seepy areas below areas of ground water discharge. The Haplaquoll <br />soils would most probably not be represented in the area if not for the large amounts of <br />supplemental water provided by irrigation activities. See Section 2.04.9, "Soil Resources <br />Information," for a detailed soils discussion. <br />February 2015 JR -66) 2.04.10-3 <br />