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Show 175 Section 11. Duma Point The Duma Point section is located north of Canyonlands National Park Highway SW 114 191 sec. on a (Island jeep in the trail above the Duma Point Road, Sky District) and west of U.S. (UTM coordinates 0588205E, 4292751E; SW 114 NW 1/4 and NW 114 30, T. 23 S., R. 18 E., Grand County, Utah). The section is measured from the top of the Summerville Formation to the basal Salt Wash Member of the Morrison Formation (Figure 49). The upper Summerville Formation here shows a weak to moderate reaction with HCL and may stain red (calcite and dolomite carbonate cement). Morrison Formation sediments Morrison Formation calcareous (calcite-cemented). (part): Salt Wash Member 9. are Thickness (m) (part): unit. Gray sandstone interbedded with mudstone and medium-grained sandstone is trough cross-bedded; sand to pebble-sized clasts are common locally. Calcite coarse-grained Ledge-forming siltstone. Fine- to cement . Total measured thickness (incomplete), Salt Wash Member 2.0 2.0 Tidwell Member: 8. Unit 6. and Slope-forming unit is mostly covered. muddy siltstone becomes purple to gray in limestone is 7. common as muddy m. Gray . Unit 5. Limestone interbedded with and Red calcareous mudstone the upper 1.4 float. Mudstone facies. purple to gray calcareous siltstone. Two thin (0.2 m) limestone 0.5 m, and a 0.6 meter-thick limestone limestone and mudstone facies. ledge ledges occurs .. siltstone occur at 1.3 m. at 0.0 and Micritic . 6. 5.0 . 1.9 Unit 4. Slope-forming unit is mostly covered. Uppermost strata may crop out where protected by the overlying limestone ledge. Purple to gray calcareous mudstone and muddy siltstone. Mudstone facies. . .. 0.65 |
