Carboniferous tectonic history of the eastern flank of the Ozark dome

Conference · Mon Mar 01 04:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:7069763

Nelson, W J ^[1]

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1. Illinois State Geological Survey, Champaign, IL (United States)

Detailed geologic mapping in southwestern Illinois and southeastern Missouri indicates that the eastern flank of the Ozark dome was a low positive area throughout Carboniferous (Mississippian and Pennsylvanian) time. Rock units of this age consistently thin onto the flank of the dome, and are punctuated by numerous disconformities. Effects of shoaling are prominent in Chesterian strata, which change from dominantly subtidal in the proto-Illinois basin to shallow subtidal, intertidal and supratidal on the flank of the dome. Although the dome probably was exposed subaerially for much of Carboniferous time, it contributed little sediment eastward. The exposed rocks were largely carbonates, which weathered by solution. Several long-lived basement structures on the east flank of the Ozarks were active during the Carboniferous. Chief among them were the Lincoln and Waterloo-Dupo anticlines, the Du Quoin monocline, and the Ste. Genevieve fault zone. All are high-angle reverse faults that strike north to northwest, and are overlain by sharp folds in sedimentary cover. Major displacements took place in late Valmeyeran to Atokan time, and addition deformation occurred in Desmoinesian through post-Pennsylvanian time. The compressional deformation probably is a product of the Ouachita orogeny.

• OSTI ID: 7069763
• Report Number(s): CONF-9303210--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 25:3
• Country of Publication: United States
• Language: English

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58 GEOSCIENCES
580000* -- Geosciences
DEVELOPED COUNTRIES
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
ILLINOIS
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