Simulating the Evolution of Fluid Underpressures in the Great Plains, by Incorporation of Tectonic Uplift and Tilting, with a Groundwater Flow Model

Figure 18

Hydraulic conductivity values used by Signor et al. [16]. Permeability values in square feet from four maps by Signor et al. [16] for hydrologic units in a study of the Great Plains of the United States. Mapped values increase from west to east, indicated by the open bars. Values between the Kansas/Colorado border and the Nemaha uplift lie within the solid (shaded) bars. Names of hydrologic units used by Signor et al. appear vertically in italics; equivalent names used in this paper appear vertically in normal font. Scale for hydraulic conductivity units (m d⁻¹) used in this paper appears at left, using a conversion of 1 m d⁻¹ = 1.19 × 10⁻¹² m². Values given by Signor and others are permeability in ft-squared, taken from maps (Figures , , , and in Signor et al. [16]). Porosity values from geophysical logs were used to compute permeability estimates using the Kozeny-Carman equation. Conversion used is (m/d) = 1.28E-11 × k (ft-squared), at standard temperature and pressure.