Author: Keith M. Clem

Publisher: Utah Geological Survey

Published: 1984

Total Pages: 173

ISBN-13: 1557910863

The Paradox Basin is a geologic area in southeastern Utah defined by the location of Pennsylvanian salt deposits. The Basin is bounded by the Uncompahgre Uplift to the east and north, the San Rafael Swell, the Circle Cliffs Uplift and the Monument Upwarp to the west, and the Defiance-Zuni Uplift and the Four Corners Platform to the south. The basin is divided into two principal tectonic subprovinces - the Paradox Fold and Fault belt to the north and the Blanding Basin to the south. The Fold and Fault Belt is an area of dominantly northwest-trending salt-cored anticlinal structures. These structures are rooted in the Precambrian basement and have influenced the stratigraphy (deposition) and structure (tectonics) of the Mississippian, Pennsylvanian, and younger formations deposited across them. The Blanding Basin was also a structural low during Pennsylvanian time. It is primarily an area of carbonate-organic mound (bioherm and bioclastic mound) deposition, which forms the most common type of reservoir for petroleum found in the region. This study includes an individual oil and gas field report and a presentation of the regional structure. Sixty-three individual petroleum fields were identified in the Utah portion of the Paradox Basin, and each are represented by data outlining the nature of the petroleum reservoir, along with its geology, structure, and location. The majority of the fields are located in the Blanding Basin subprovince. The regional structure is represented by a structure map of the Ismay zone of the Paradox Formation (Plate 1), elevation at which first salt is encountered in the Paradox Formation (Plate 2), and an isopach map of the salt bed interval in the Paradox Formation (Plate 3). The Ismay Member was chosen to be a representative oil horizon of the Paradox Basin and illustrates the predominant tectonic structures as well as the subtle petroleum related structures. The isopach map of the salt bed interval determines the evaporite boundary in the Basin and illustrates the fold and fault subprovince and corresponding structures. 162 pages + 4 plates