Research Article

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

Figure 30

Results of running the fifth model, the 4.5 Ma model, representing the 2.5-million-year period from 7 to 4.5 Ma, compared to present-day heads. Model curves , , and (Wolfcampian, Desmoinesian, and Mississippian, resp.) are further approaching the present-day data curves. Red triangles at centroids of the grid columns mark the initial zero heads at 70 Ma.