Laserfiche WebLink
<br />. <br /> <br />. <br /> <br />W <br />C:,) <br />N <br />00 <br /> <br />. <br /> <br />. <br /> <br />. <br /> <br />. <br /> <br />. <br /> <br />. <br /> <br />. <br /> <br />. <br /> <br />. <br /> <br />formations. The Morrison formation is siltstone and mudstone inter- <br /> <br />bedded with sandstone. Zones of massive quartzose sandstone are common <br /> <br />throughout the region. <br /> <br />Marine and continental rocks intermixed are found in about 28 per- <br /> <br />cent of the basin. This situation occurs through the inter- tonguing and <br /> <br />overlapping formations of continental sandstone and marine shale. The <br /> <br />shale is predominately mancos shale and the mesa verde group. The <br /> <br />grouping consists of limestone, dolomite, sandstone, shale, mudstone, <br /> <br />gypsum and saiine minerals. Outcrops of these materials occur along <br /> <br />the Book Cliffs, and on the Wasatch, Aquarius, and Kaiparowitz plateaus. <br /> <br />The mixture of marine and continental rocks also are found in areas uf <br /> <br />the San Juan and Rocky Mountains, the Green River Basin in Wyoming, <br /> <br />and the Uintah Basin in Utah. <br /> <br />The youngest deposits in the basin are surficial deposits from the <br /> <br />weathering of older rocks. These surficial deposits are unconsolidated <br /> <br />deposits and are estimated to cover 75 percent (82,000 square miles) of <br /> <br />the bedrock in the Upper Colorado River Basin. The deposits vary in <br /> <br />thickness from thin layers to beds of a hundred or more feet. <br /> <br />ln the mountains where moisture and temperature are adequate the <br /> <br />unconsolidated residuum have developed into moderately mature soils. <br /> <br />Here the parent material is of crystalline, igneous, metamorphic, or <br /> <br />volcanic origin. The residuum is relatively insoluble. <br /> <br />Surface soils of the interior valleys are underlain predominately by <br /> <br />9 <br /> <br />, <br />