Arizona, Nevada, and California

Comments on Geologic Parameters

08 Continuity of Top Seal:

Maps of top-seal continuity of aquifers in the Mojave Basin and adjacent areas were not found during our search. However, schematic cross sections of Paleozoic carbonates in Nevada in Prudic and others (1995) show that shaly limestone top seals are several miles in extent. However, the continuity of these top seals is commonly disrupted by subsurface fracture systems, faults, and intrusive igneous bodies (Planert, 1996). Cross sections in the basin-and-range province in Arizona show locally extensive continuity of fine-grained central-basin siltstones and mudstones above alluvial-fan wedges (Freethey and others, 1986).

08 Reference:

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.

Planert, M., 1996, Ground water atlas of the United States, Segment 1: California and Nevada: U.S. Geological Survey Atlas.

Prudic, D. E., Harrill, J. R., Burbey, and Thomas J., 1995, Conceptual evaluation of regional ground-water flow in the carbonate-rock province of the Great Basin, Nevada, Utah, and adjacent states: U.S. Geological Survey Professional Paper P-1409-D, 102 p.