The Ozark Uplift and related structural elements, a view from the north bunker

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

OSTI ID:5025476

Bunker, B J; Witzke, B J; Ludvigson, G A ^[1]

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1. Iowa Dept. of Natural Resources, Iowa City, IA (United States). Geological Survey Bureau

The structural/stratigraphic framework of the central Midcontinent region has been evaluated utilizing a series of isopach and paleogeographic maps constructed within the framework of Sloss' (1963) sequences. General northward-trending Sauk structural patterns were replaced by more easterly-trending patterns across Iowa and Illinois during the M, and U. Ordovician, coincident with initial upwarping of the Ozark Uplift. Silurian strata in this region are largely restricted to the East-Central Iowa and North Kansas basins and the east-west trending structural sag connecting these two basins. The structural framework influencing early Kaskaskia deposition was largely inherited from that which developed during the late Tippecanoe. The Iowa Basin, which formed during the late Middle to Late Devonian, represents an intrashelf basin which developed on the Midcontinent Carbonate shelf in which shallow-water and mudflat sedimentation kept pace with increased subsidence. The present thickness of Mississippian rocks in the Midcontinent reflects extensive pre-Absaroka uplift and erosion. Structural deformation during the Early-Middle Pennsylvanian (Nemaha Uplift) bisected the region of the North Kansas Basin and cut off the southwestern extension of the Kaskaskia Iowa Basin. Up to 320 m of pre-Missourian rocks accumulated in the structural depression east of the Humboldt Fault Zone (Forest City Basin). The Forest City Basin was a relatively short-lived asymmetric fault-bounded sedimentary basin that subsided in synchrony with the ascension of the Nemaha Uplift. Earlier and subsequent Phanerozoic sedimentation in the area occurred in short-lived depositional basins whose structural geometries were strikingly dissimilar.

• OSTI ID: 5025476
• 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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