Although direct information from deep boreholes and indirect data from geophysics add significantly to interpretations, the geometry and composition of the basin fill remain the most fruitful fields from which to draw inferences on the behavior of major sedimentary basins. Geometric and compositional data are capable of analysis to yield interpretations through geologic time of the rate of subsidence in basins, their degree of differentiation from surrounding neutral and positive elements, the positions and stability of the hingelines along which such differentiation is accomplished, and the position and character of source areas contributing to the basin fill.

Evaluation of the sedimentary record of basins in the interior of the North American craton indicates that, for the period since late Precambrian, such basins, in harmony with the rest of the craton, have been involved in six major sedimentary cycles. Four of these, corresponding with the times of accumulation of the Sauk, Tippecanoe, Kaskaskia, and Zuni Sequences, exhibit records of five distinct stages that appear to have simultaneous effects on all cratonic basins. None of the cratonic cycles shows any systematic correlation in space and time with orogenic events in extracratonic mobile belts.

These essentially stratigraphic deductions raise questions that require consideration in the development of geologically meaningful basin models. Such models must include simultaneous consideration of the composition, structure, and dynamics of the continental crust and upper mantle.

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