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<br />type of master channel into which they drain, the variable composition <br />and erosional resistance of the bedrock, and local effects due to <br />W aspect. Field observations indicate that all channels in the study <br />....... <br />tn basins are incising. <br />en <br /> <br />Hillslopes <br /> <br />Hillslopes were studied by measuring valley cross sections within <br />the eight basins (Fig. 3-6). There is a wide range of hillslope <br />gradients within basins and between basins (Table 3-2). Although <br />hills lope gradients differ widely, characteristic hillslope shapes are <br />evident (Fig. 3-7). Convex hillslopes are characteristic of the upper <br />portions of all the basins (Fig. 3-7a). Figure 3-7b illustrates convex <br />concave slopes that occur in the middle portions of all the basins. The <br />convex-concave hillslopes alternate on opposite sides of the valleys. <br />This alternation appears to be controlled by the meandering channel <br />configuration at the slope base as opposed to control by either rock <br />type, rock structure, or aspect. Finally, concave slopes are found near <br />the mouths of all of the basins Fig. 3-7c). <br />Soil depths were measured in six of the eight basins. Soil depth is <br />the thickness of the layer of residual material derived from underlying <br />weathered, yet structurally distinct, bedrock. The soils are derived <br />from two lithologies in the Mancos Shale, shale and sandy shale. Field <br />observations indicate that portions of the badlands are underlain <br />predominantly by shale, of which Basins A, N, and Q are examples. <br />Basins 5, T, and U are underlain by interbedded shale and sandstone. <br />Soil texture analyses by Lusby, et al (1963) show that soils deri ved <br />from shales are clay-rich, while soils derived from interbedded shale <br />and sandstone are mixtures of clay and sand. <br />An analysis of variance was conducted to compare the means of soil <br />depth for divides and hillslopes within each basin. In five of the six <br />basins, there is no significant difference in soil depth between divides <br />and hillslopes. Therefore, the divides and hillslopes apparently have <br />equal rates of soil development and/or erosion. However, Basin U is an <br />exception where soil depth is significantly greater on the divides than <br />on the hillslopes. Soil depths are the same in basins of the same <br />lithology, but the mean soil depth for basins underlain by interbedded <br /> <br />44 <br />