General Setting
Information Search and Selection

Com ments

on

Geo logic

Para meters

1 Depth:

2 Permeability/Hydraulic Conductivity:

3 Formation Thickness:
4 Net Sand Thickness:
5 Percent Shale:
6 Continuity:
7 Top Seal Thickness:
8 Continuity of top seal:
9 Hydrocarbon Production:
10 Fluid Residence Time:
11 Flow Direction Elevation:

12

CO2 Solu bility Brine

 12a Temperature:
12b Pressure:
12c Salinity:
13 Rock/Water Reaction:
14 Porosity:
15 Water Chemistry:
16 Rock Mineralogy:

St. Peter Sandstone, Illinois Basin

Comments on Geologic Parameters

8 Continuity of Top Seal:

The Maquoketa Shale and the underlying Galena, Decorah, Platteville, and Glenwood Formations are an effective aquiclude between the St. Peter Sandstone and overlying Silurian and younger strata. To characterize the continuity of the Maquoketa Shale in the GIS, we chose the map of Mandle and Kontis (1992), which shows vertical hydraulic conductivity values for the confining unit. Note that these data do not account for the effectiveness of the Galena, Decorah, Platteville, and Glenwood Formations as aquicludes, which also serve to hydraulically isolate the St. Peter Sandstone from overlying units.

8 Map:

8 Reference:

Mandle, R. J., and Kontis, A. L., 1992, Simulation of regional ground-water flow in the Cambrian-Ordovician aquifer system in the northern Midwest, United States: U.S. Geological Survey, Professional Paper 1405-C.