Strontium isotopic study of subsurface brines from Illinois basin
The abundance of the radiogenic isotope /sup 87/Sr in a subsurface brine can be used as a tracer of brine origin, evolution, and diagenetic effects. The authors have determined the /sup 87/Sr//sup 86/Sr ratios of over 60 oil-field waters from the Illinois basin, where brine origin is perplexing because of the absence of any significant evaporite strata. Initially, they analyzed brines from 15 petroleum-producing sandstone and carbonate units; waters from Ordovician, Silurian, Devonian, and Mississippian strata have /sup 87/Sr//sup 86/Sr ratios in the range 0.7079-0.7108. All but those from the Ste. Genevieve Limestone (middle Mississippian) are more radiogenic in /sup 87/Sr//sup 86/Sr than seawater values for this interval of geologic time. The detrital source of the more radiogenic /sup 87/Sr may be the New Albany Shale group, considered to be a major petroleum source rock in the basin. The /sup 87/Sr//sup 86/Sr ratios of Ste. Genevieve brines apparently evolved without a contribution from fluid-shale interaction.
- Research Organization:
- Mobil Research and Development Corp., Farmers Branch, TX
- OSTI ID:
- 5201145
- Report Number(s):
- CONF-860624-
- Journal Information:
- Am. Assoc. Pet. Geol., Bull.; (United States), Vol. 70:5; Conference: American Association of Petroleum Geologists annual meeting, Atlanta, GA, USA, 15 Jun 1986
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BRINES
STRONTIUM ISOTOPES
ILLINOIS
SEDIMENTARY BASINS
CARBONATE ROCKS
DEVONIAN PERIOD
DIAGENESIS
ISOTOPE RATIO
MISSISSIPPIAN PERIOD
ORDOVICIAN PERIOD
ORIGIN
PETROLEUM DEPOSITS
SANDSTONES
SHALES
SILURIAN PERIOD
SOURCE ROCKS
ALKALINE EARTH ISOTOPES
FEDERAL REGION V
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
ISOTOPES
MINERAL RESOURCES
NORTH AMERICA
PALEOZOIC ERA
RESOURCES
ROCKS
SEDIMENTARY ROCKS
USA
020200* - Petroleum- Reserves
Geology
& Exploration