Field trip no. 5 from “Geologic Excursions to the Rocky Mountains and Beyond,” field trip guidebook of the 1996 Annual Meeting of the Geological Society of America. (SP-44 has the complete set.) 23 pages. Digital PDF download. OF-96-04-05D
From the Introduction:
This four-day field trip examines Pennsylvanian to Jurassic strata in the Paradox Basin on the Colorado Plateau in southeastern Utah. The trip will emphasize four major themes: 1) Permian-Triassic stratigraphy, 2) depositional systems, 3) paleogeography, and 4) paleoclimate. The trip follows depositional facies in the Permian and Triassic section from proximal continental facies near the ancestral Rocky Mountains in the Uncompahgre Highlands to distal marine settings within the Paradox Basin. Evolution of these depositional systems from the late Paleozoic to the early Mesozoic, a key period along the west coast of Pangea for paleogeographic and paleoclimatic reconstructions, is examined. The trip highlights unconformities and their development by the effects of sea-level change, regional tectonics, and salt diapirism. The trip also integrates depositional sequences of red beds with paleoclimate interpretations and hydrocarbon resources in the Paradox Basin. Rocks examined in detail include the Permian Cutler Group (Halgaito Formation, Cedar Mesa Sandstone, Organ Rock Formation, White Rim Sandstone, and De Chelly Sandstone), the overlying Lower Triassic Moenkopi Formation, and locally the Upper Triassic Chinle Formation. The trip also passes through the underlying Pennsylvanian section and the overlying Jurassic section, including eolianites exposed in and around Canyonlands National Park.