Basin Fill Sandstone and Carbonate Aquifers, Basin and Range (Arizona, Nevada, and California)

Comments on Geologic Parameters

7 Top Seal Thickness:

Top-seal-thickness maps are lacking for the two principal hydrologic units in the Mojave Basin. Top seals for the deeply buried carbonate aquifers are a combination of upper Paleozoic marine shales, siliceous siltstone, and evaporites. The hydraulic conductivity of these noncarbonate rocks is commonly only 0.01 ft/d (Dettinger and others, 1995; Thomas and others, 1996). Although these noncarbonate seal facies are up to 200 ft (61 m) thick in north-central Nevada, they exhibit pinch-outs. Interbedded tuffaceous sediments and central-basin fine-grained sediments (lacustrine fill and playa) are the main seals for the Tertiary basin-and-range aquifers (Freethey and others, 1986; Harrill and others, 1988; Prudic and others, 1995).

7 Reference:

Dettinger, M. D., Harrill, J. R., Schmidt, D. L., and Hess, J. W., 1995, Distribution of the carbonate rock aquifers and the potential for their development, southern Nevada and adjacent parts of California, Arizona, and Utah: U.S. Geological Survey Water-Resources Investigations WRI 91-4146, 100 p., 2 sheets.

Freethey, G. W., Pool, D. R., Anderson, T. W., and Tucci, Patrick, 1986, Description and generalized distribution of aquifer materials in the alluvial basins of Arizona and adjacent parts of California and New Mexico: U.S. Geological Survey Hydrologic Investigations Atlas HA-663, scale 1:500,000, 4 sheets.

Harrill, J. R., Gates, J. S., and Thomas, J. M., 1988, Major ground-water flow systems in the Great Basin region of Nevada, Utah, and adjacent states: U.S. Geological Survey Hydrologic Investigations Atlas HA-694-C, scale 1;1,000,000, 1 sheet.

Thomas, J. M., Welch, A. H., and Dettinger, M. D., 1996, Geochemistry and isotope hydrology of representative aquifers in the Great Basin region of Nevada, Utah, and adjacent states: U.S. Geological Survey Professional Paper 1409-C, p. C1-C100.

 
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