Abstract: High Resolution Stacking Patterns of Wave-Dominated Deltaic Parasequences, Kenilworth Member, Book Cliffs, Utah

Simon A. J. Pattison

The Kenilworth Member (Blackhawk Formation, Campanian) is well exposed in the Book Cliffs of Utah from Price to east of Green River (Hatch Mesa). It forms one of the lowest cliff forming sandstone bodies m the Book Cliffs and varies in thickness from 50 to 100 meters.

Five facies associations are observed in the Kenilworth: coastal plain, channels/incised valleys, upper shoreface/foreshore, lower shoreface and inner shelf/offshore transition. The facies associations combine to form coarsening-upward, wave-dominated deltaic successions or parasequences that are capped by upper shoreface or channel sandstones. Individual parasequences are 7 to 35 m thick, and are subdivided into smaller sanding-upward successions or bedsets that are 2 to 20 m thick. A maximum of five bedsets are observed within a parasequence.

Six parasequences are observed in the Kenilworth. Parasequences 1 to 5 form an aggradational to progradational parasequence set, that comprises both the highstand and lowstand systems tracts. Parasequence 6 is thinner, muddier and retrogradational relative to the underlying parasequences, and forms the transgressive systems tract.

A sequence boundary is observed at the top of parasequence 4 which can be traced basinward into the Price River and Battleship Butte sharp based shorefaces. These shorefaces are interpreted as forced regression lowstands. Previous interpretations suggest that the Kenilworth lowstand occurs 15 km further basinward at Hatch Mesa. This study clearly shows that the top of the Hatch Mesa sand body (Emery age?) is at least 80 m below the base of the Kenilworth.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994