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

5 Percent Shale:

The St. Peter Sandstone is a mature quartz arenite that contains little or no silt and clay, except near its perimeter. Lamar (1928; his fig. 10) provided results of grain-size analysis for a number of St. Peter Sandstone samples in which the percent clay ranged from 0 to 5.8 with a mean of about 2.5 percent. Because clay is a minor constituent of the St. Peter Sandstone, we simply assign the percent shale to be 2.5 throughout the central Illinois Basin.

5 Reference:

Lamar, J. E., 1928, Geology and economic resources of the St. Peter Sandstone of Illinois: Illinois Geological Survey Bulletin No. 53, 175 p.