Field-saturated hydraulic conductivity of unsaturated surficial deposits along the southern extent of the Illinoian glaciation, southern Illinois
- Southern Illinois Univ., Carbondale, IL (United States). Dept. of Geology
In southern Illinois, glacially-derived surficial deposits control recharge and the migration of contaminants to regional groundwater resources. This study measured the field-saturated hydraulic conductivity of the diamicton and the overlying loess with a Guelph permeameter specially modified to take measurements to a depth of 5 m. Six field sites were chosen, along a transect trending about 50 kilometers southeast of the Mississippi Valley. Along this transect, the loess units thin dramatically, from 8 to 1 m and from 6 to 0.2 m for the Peoria and Roxana Silts, respectively, and the relative influence of the Ohio/Wabash Valleys source area increases. Twenty boreholes were drilled at each site at a spacing of 1.5 m forming a random grid pattern. Initial conductivity tests were conducted near the base of the loess in the B/C, or where possible C, horizon of the modern soil. Boreholes were then deepened and tests were conducted within the oxidized diamicton. The statistical relation between field-saturated hydraulic conductivity, particle size distribution, clay mineralogy, fracture distribution, and weathering zone was investigated. The main factors influencing spatial variability in field-saturated hydraulic conductivity are: (1) particle size distribution, (2) clay mineralogy, and (3) differences in soil development. Source area (Mississippi vs. Ohio/Wabash Valley systems) and distance from the source area control these physical factors.
- OSTI ID:
- 5816502
- Report Number(s):
- CONF-921058-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 24:7; Conference: 1992 annual meeting of the Geological Society of America (GSA), Cincinnati, OH (United States), 26-29 Oct 1992; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
58 GEOSCIENCES
AQUIFERS
HYDRAULIC CONDUCTIVITY
ILLINOIS
BOREHOLES
CLAYS
GEOLOGIC FRACTURES
MINERALOGY
PARTICLE SIZE
SOILS
SOURCE ROCKS
WEATHERING
CAVITIES
DEVELOPED COUNTRIES
GEOLOGIC STRUCTURES
NORTH AMERICA
SIZE
USA
540250* - Environment
Terrestrial- Site Resource & Use Studies- (1990-)
580000 - Geosciences