Chapter 7.4, Page 2 of 4

Hydrogeologic Units

South Park is a highly complex structural and depositional basin. A generalized geologic cross-section (Figure 7.4-2) located about 5 miles north of Antero Reservoir illustrates the complex nature of this synclinal basin and shows the structural relationships of the sedimentary rock units. Most of the sedimentary rock formations within South Park are potential aquifers.

Figure 7.4.2 Generalized geologic cross section of the South Park region.
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Tertiary age sedimentary rocks in South Park are more than 11,000 feet thick. The youngest sedimentary rock aquifers in South Park are within the Trump and underlying Wagontongue Formations. A stratigraphic sequence depicting the hydrogeologic units and their hydrologic characteristics is presented as Table 7.4-1. Several members of the South Park Formation form one of the more dominant aquifers in the park. The South Park Formation is equivalent to the Denver Formation of the Denver Basin.

Table 7.4.1 Hydrogeologic Units of South Park Basin
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Chapter 7.4, Page 2 of 4