Currie, C: Kenilworth Member, Upper Cretaceous, Book Cliffs,

The Book Cliffs of eastern Utah contain some of the best exposures to shallow marine strata in the world. The cliffs extend almost continuously for 300 km from Helper, Utah to Grand Junction in Colorado. Along these cliffs are numerous canyons which have provided researchers with an excellent three dimensional image of the geology that has been exposed. Within these strata two clastic wedges have been identified: the Star Point Formation and the Blackhawk Formation. The Blackhawk Formation contains six members, of which the Kenilworth Member is the focus of this work. Through a petrographic study, it was noted that moving down-dip on the shoreface the grain size decreased as well as the quartz content. These trends support the expected transition from a sand-rich shoreface environment to a mud-rich shelf environment. The shelf bodies are anomalous sand-rich lenses or lobate bodies completely encased in shelf mudstones. The origin of these bodies is still under debate but petrographically these bodies are similar to the lower attached shoreface sandstones and support both the detached shoreface hypothesis and subaqueous channels hypothesis proposed by Pattison (2006).