PHANEROZOIC HISTORY OF THE CENTRAL MIDCONTINENT, UNITED STATES

by
B.J. Bunker, B.J. Witzke, W.L. Watney, G.A. Ludvigson

The Geology of North America
Vol. D-2, Sedimentary Cover - North American Craton: U.S.
The Geological Society of America, 1988, p. 243-260

INTRODUCTION


The region of the central midcontinent has commonly been termed the "stable interior" of the North American continent. The magnitudes of Phanerozoic crustal deformation in the cratonic interior certainly are very small compared to those known from active continental margins, and the rates of deformation have been generally slower (Schwab, 1976). Nevertheless, the Phanerozoic sedimentary record in the central midcontinent region is replete with evidences of tectonic activity of surprising diversity and pattern. The central midcontinent, as defined for this report, includes Iowa, Kansas, southeastern South Dakota, Nebraska (excluding the panhandle), southern Minnesota, and Missouri north of 37 degree north latitude.

The Phanerozoic stratigraphic record in the central midcontinent region of North America is divided into six major depositional sequences, each bounded by major interregional unconformities (Sloss, 1963). The structural and stratigraphic development of this region is evaluated utilizing a series of isopach and paleogeologic maps constructed within the general framework of Sloss' (1963) cratonic sequences.