Abstract

The rate of transgression is one of the primary factors that determine the character of preserved stratigraphic sequences. Slow transgressions result in reworking of underlying sediment and interfingering of facies. In contrast, rapid transgressions may be characterized by nearly complete preservation of underlying strata and structures, and a lack of interfingering deposits.

The White Rim Sandstone (Permian), in southeastern Utah, U.S.A., provides a well exposed example of the effective stratigraphic preservation of a sandstone sequence that was transgressed during a relative sea-level rise sometime between the late Leonardian and the mid-Guadalupian. This event resulted in the flooding of, at first, a coastal dune complex in the west, and later an erg interior environment to the east, farther inland. The initial, slow rise is recorded by reworked eolian sands and the interfingering of eolian and marine facies. As the transgression moved farther inland across the erg, the rate of relative sea-level rise increased, and resulted in only minor reworking of eolian strata, and preservation of significant eolian paleotopography.

Despite the change in rate of relative sea-level rise through time, a distinctly episodic character can be documented throughout. During the initial, slow phase of the rise, stillstands were of long enough duration to permit seaward progradation of eolian sands. Stillstands during the final, rapid phase of the relative sea-level rise were short and shoreline related features are consequently not preserved.