Organic geochemical and tectonic evolution of the midcontinent rift system: Organic geochemistry and micropaleontology

Technical Report · Mon Jun 05 04:00:00 EDT 1989

OSTI ID:5628359

Hayes, J M; Pratt, L M; Knoll, A H ^[1]

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1. Indiana Univ., Bloomington, IN (USA)

Siltstones and shales of the mid-Proterozoic Nonesuch Formation are widely postulated to be effective petroleum source rocks based on the occurrence of active oil seeps and tarry residues within parts of the Copper Range Mine. Most previous organic geochemical research has focused on mineralized sedimentary strata and associated oils in the lower-most 5 meters of the Nonesuch Formation exposed in mine excavations. Recently, non-mineralized sediments from outcrops along the shore of Lake Michigan and exploration cores drilled along the subsurface trend to the east of White Pine have been studied. Substantial variation in the lateral and vertical distribution of fine-grained facies within the Nonesuch is apparent from our studies of the non-mineralized suites of samples. Research at Indiana University is focused on the relationship between organic geochemistry and depositional environment in the Nonesuch Formation. Our principal objectives are (1) to describe the distribution of fine-grained lithofacies; (2) to determine organic-carbon, carbonate-carbon, and total-sulfur contents of these units; (3) to characterize the extractable bitumen and conduct preliminary analyses of selected biomarkers (hopanoids, steroids, and monomethyl-substituted cyclohexyl alkanes); and (4) to infer the depositional environment and biological affinities of organic matter preserved in the Nonesuch. These data will be used to evaluate the regional source-rock potential of the Nonesuch Formation. A parallel study of sedimentary structures, petrography, and organic geochemistry of the slightly older Belt Group in Montana will provide a context for interpretation of the Nonesuch results. 16 refs., 14 figs., 2 tabs.

• Research Organization: Indiana Univ., Bloomington, IN (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: FG02-88ER13978
• OSTI ID: 5628359
• Report Number(s): DOE/ER/13978-1; ON: DE89017561
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
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CARBONATE ROCKS
CHEMISTRY
DOCUMENT TYPES
FEDERAL REGION V
GEOCHEMISTRY
GEOLOGIC DEPOSITS
GEOLOGY
LIMESTONE
MICHIGAN
MINERAL RESOURCES
NORTH AMERICA
PETROLEUM DEPOSITS
PROGRESS REPORT
RESOURCES
ROCKS
SEDIMENTARY ROCKS
SHALES
SOURCE ROCKS
STRATIGRAPHY
USA
WISCONSIN