CHANGES IN RATE OF TRANSGRESSION ACROSS THE PERMIAN WHITE RIM SANDSTONE, SOUTHERN UTAH

A change in the rate of transgression of the Permian Kaibab sea across southern Utah is proposed on the basis of stratal relations and prese rved paleotopography in the Permian White Rim Sandstone. As the Kaibab sea transgressed southern Utah, across a generally west-dipping conti nental margin, the rate of transgression increased. Interbedded coasta l dune sandstones (White Rim Sandstone) and marine carbonates (Kaibab Limestone) reflect slow transgression across what is now south-central Utah. Preserved paleotopography and the absence of intertonguing of c arbonates and sandstones in southeastern Utah reflects a more rapid tr ansgression, indicating that the rate of sea-level rise increased with time. Throughout the transgression, relative rise in sea level was di scontinuous, and punctuated by stillstands. In general, intervening st illstands decreased in duration as the transgression progressed. This change in transgression rate can be interpreted in one of two ways: ra te of regional sea-level rise across southern Utah increased with time , or previously unrecognized and localized subsidence occurred in east ern Utah during Kaibab transgression. Although regional tectonism is i mportant, we favor the former interpretation because no independent ev idence of local tectonic movement can be found.