Sulfur isotope evidence for regional recharge of saline water during continental glaciation, north-central United States

Journal Article · Thu Nov 01 00:00:00 EST 1990 · Geology; (USA)

DOI:https://doi.org/10.1130/0091-7613(1990)018<1054:SIEFRR>2.3.CO;2· OSTI ID:5796857

Siegel, D I ^[1]

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1. Syracuse Univ., NY (USA)

Sulfate concentrations in ground water from the Cambrian-Ordovician aquifer of south-eastern Wisconsin and northern Illinois increase up to hundreds of times where the aquifer is confined beneath the Maquoketa Shale. There is no sulfate source in the aquifer or overlying rocks except for minor amounts of finely disseminated pyrite. Coinciding with increasing sulfate concentrations, {delta}{sup 34}S of the dissolved sulfate increases from less than {minus}5{per thousand} in the unconfined part of the aquifer to a nearly constant value of +20{per thousand} where the aquifer is confined and where sulfate reduction is minimal. The most likely source for this isotopically heavy sulfate is ground water associated with Silurian evaporites under Lake Michigan. It is uncertain if the sulfate-rich water was emplaced in pulses or mostly during the last glaciation.

• OSTI ID: 5796857
• Journal Information: Geology; (USA), Vol. 18:11; ISSN 0091-7613
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
AQUIFERS
RECHARGE
GROUND WATER
GEOCHEMISTRY
ILLINOIS
WISCONSIN
CONTAINMENT
ECOLOGICAL CONCENTRATION
EVAPORITES
GEOLOGIC HISTORY
GLACIERS
HYDROLOGY
ISOTOPE RATIO
LAKE MICHIGAN
LIQUID FLOW
ORIGIN
SHALES
SILURIAN PERIOD
SOURCE ROCKS
SULFATES
SULFUR 34
CHEMISTRY
EVEN-EVEN NUCLEI
FEDERAL REGION V
FLUID FLOW
GEOLOGIC AGES
GREAT LAKES
HYDROGEN COMPOUNDS
ISOTOPES
LAKES
LIGHT NUCLEI
NORTH AMERICA
NUCLEI
OXYGEN COMPOUNDS
PALEOZOIC ERA
ROCKS
SEDIMENTARY ROCKS
STABLE ISOTOPES
SULFUR COMPOUNDS
SULFUR ISOTOPES
SURFACE WATERS
USA
WATER
580000* - Geosciences