Geochemistry of the Cambrian-Ordovician aquifer system in the northern Midwest, United States

Journal Article · Sun Jan 01 04:00:00 EST 1989 · United States Geological Survey, Professional Paper; (USA)

OSTI ID:6316889

Siegel, D I

Distributions of solutes in aquifers of Cambrian and Ordovician age were studied in Minnesota, Wisconsin, Iowa, Illinois, northwestern Indiana, and northern Missouri to determine the sources of solutes and the probable chemical mechanisms that control regional variations in water quality. The data base used included more than 3,000 ground-water-quality analyses from all major aquifers, but especially from the St. Peter, Jordan, and Mount Simon Sandstones and their equivalents. Regional variations in the water chemistry of glacial drift and other sedimentary units that overlie the Cambrian-Ordovician aquifer system in recharge areas in Minnesota, Iowa, Wisconsin, and Illinois were also studied, but to a lesser degree. The most important chemical variation in the aquifer is the change in water type from calcium-sodium-sulfate-bicarbonate water to sodium-calcium-sulfate-bicarbonate and sodium-chloride waters along the longest regional flow path from northwestern Iowa to the Illinois basin. The most striking aspect of the distribution of dissolved solids and carbon isotopic content of bicarbonate is the increase in concentration and isotopic enrichment from southwestern Wisconsin, southern Minnesota, and northwestern Illinois south toward Missouri. This study indicates that the ground water in the region is thousands of years old. The study also indicates that the major chemical trends in the aquifers probably are related as much to paleohydrogeologic flow systems during Pleistocene time as to the present flow system, which may postdate the retreat of the last ice sheet about 12,000 years ago.

• OSTI ID: 6316889
• Journal Information: United States Geological Survey, Professional Paper; (USA), Journal Name: United States Geological Survey, Professional Paper; (USA) Vol. 1405-D; ISSN XGPPA
• Country of Publication: United States
• Language: English

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54 ENVIRONMENTAL SCIENCES
540310 -- Environment
Aquatic-- Basic Studies-- (1990-)
58 GEOSCIENCES
580000* -- Geosciences
AGE ESTIMATION
ALKALI METALS
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METALS
ALPHA DECAY RADIOISOTOPES
AQUIFERS
ARSENIC
BERYLLIUM
BROMIDES
BROMINE COMPOUNDS
CADMIUM
CALCIUM
CAMBRIAN PERIOD
CARBON 14 DECAY RADIOISOTOPES
CARBON COMPOUNDS
CARBON ISOTOPES
CARBONATES
CENOZOIC ERA
CHEMICAL ANALYSIS
CHEMISTRY
CHLORIDES
CHLORINE COMPOUNDS
DISSOLUTION
DISTRIBUTION
ECOLOGICAL CONCENTRATION
ELEMENTS
ENVIRONMENTAL QUALITY
EVEN-EVEN NUCLEI
FEDERAL REGION V
FEDERAL REGION VII
FLUORIDES
FLUORINE COMPOUNDS
GEOCHEMISTRY
GEOLOGIC AGES
GROUND WATER
HALIDES
HALOGEN COMPOUNDS
HEAVY ION DECAY RADIOISOTOPES
HEAVY NUCLEI
HYDROGEN COMPOUNDS
HYDROLOGY
ILLINOIS
INDIANA
IOWA
ISOTOPE RATIO
ISOTOPES
LITHIUM
METALS
MINERALOGY
MINNESOTA
MISSOURI
NORTH AMERICA
NUCLEI
ORDOVICIAN PERIOD
OXYGEN COMPOUNDS
PALEOZOIC ERA
PLEISTOCENE EPOCH
QUANTITY RATIO
QUATERNARY PERIOD
RADIOISOTOPES
RADIUM 226
RADIUM ISOTOPES
RECHARGE
REGIONAL ANALYSIS
ROCKS
SEDIMENTARY ROCKS
SEMIMETALS
SODIUM
SOLUTES
STRONTIUM
SULFATES
SULFUR COMPOUNDS
TRACE AMOUNTS
TRANSITION ELEMENTS
USA
VANADIUM
VARIATIONS
WATER
WATER CHEMISTRY
WATER QUALITY
WISCONSIN
YEARS LIVING RADIOISOTOPES