SEDIMENTOLOGY, CHRONOSTRATIGRAPHY, AND RESERVOIR CHARACTERIZATION OF THE TWIST GULCH FORMATION: A PALEOGEOGRAPHIC RECONSTRUCTION OF THE UPPER MIDDLE JURASSIC (CALLOVIAN TO OXFORDIAN) OF CENTRAL UTAH

The sedimentology and stratigraphy of the Twist Gulch Formation have not been well studied. The Twist Gulch Formation must be understood in these contexts in order to reconstruct the paleogeogeography of central Utah and to correlate it with time-equivalent formations such as the Entrada, Curtis, and Summerville formations. The facies changes that occur between the Twist Gulch and correlative formations are also poorly understood because they occur beneath the Wasatch Plateau and are not exposed. We will study the Twist Gulch Formation at its type-section along the west flank of the San Pitch Mountains of central Utah, in Salina Canyon, and potentially other locations in Utah. We will also study the sabkha facies of the Entrada Sandstone (San Rafael Group) in central Utah and reference past studies of the Entrada Sandstone, Curtis, and Pruess Formations in an attempt to fit these formations into a chronostratigraphic framework.