The Lower Cretaceous in east-central Utah—The Cedar Mountain Formation and its bounding strata

  • James I. Kirkland Utah Geological Survey
  • Marina Suarez Department of Geological Sciences, The University of Texas at San Antonio
  • Celina Suarez Department of Geosciences
  • ReBecca Hunt-Foster Bureau of Land Management
Keywords: Cedar Mountain, Stikes Quarry, Cretaceous


Although only recognized as a discrete stratigraphic unit since 1944, the Cedar Mountain Formation represents tens of millions of years of geological and biological history on the central Colorado Plateau. This field guide represents an attempt to pull together the results of recent research on the lithostratigraphy, chronostratigraphy, sequence stratigraphy, chemostratigraphy, and biostratigraphy of these medial Mesozoic strata that document the dynamic and complex geological history of this region. Additionally, these data provide a framework by which to examine the history of terrestrial faunas during the final breakup of Pangaea. In fact, the medial Mesozoic faunal record of eastern Utah should be considered a keystone in understanding the history of life across the northern hemisphere. Following a period of erosion and sediment bypass spanning the Jurassic–Cretaceous boundary, sedimentation across the quiescent Colorado Plateau began during the Early Cretaceous. Thickening of these basal Cretaceous strata across the northern Paradox Basin indicate that salt tectonics may have been the predominant control on deposition in this region leading to the local preservation of fossiliferous strata, while sediment bypass continued elsewhere. Thickening of overlying Aptian strata west across the San Rafael Swell provides direct evidence of the earliest development of a foreland basin with Sevier thrusting that postdates geochemical evidence for the initial development of a rain shadow.

Cedar Mountain Formation at the Stikes Quarry on Utahraptor Ridge. The Stike Quarry (just below sandstone cliff) is in the upper Yellow Cat Member. The underlying Morrison Formation is the reddish slope at the bottom of photograph and the Naturita Formation caps the ridge.
How to Cite
Kirkland , J., Suarez , M., Suarez , C., and Hunt-Foster , R., 2016, The Lower Cretaceous in east-central Utah—The Cedar Mountain Formation and its bounding strata: Geology of the Intermountain West, v. 3, p. 101-228., doi: 10.31711/giw.v3.pp101-228.

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