Green River Basin


Exposures of Green River Formation along I-80

The Uinta Mountains that bound the Green River Basin to the south appear to have been uplifted during the Early Eocene (53mya) based on the geochemistry of sediments (indicating granite source rocks) in the lacustrine Luman Member of the Green River Formation (Swanson, 2003). However, large scale conglomerates only appear much later during the Oligocene, with radiometric dates of the Bishop Conglomerate around 30 to 34 mya (Balls et al. 2004). Sevier Belt deposition to the west accounts for older Paleocene sedimentary rocks of the Evanston Formation in the Green River Basin.

Balls, E., Kowallis, B.J., Christiansen, E.H., Sprinkel, D.A., and Heizler, M.T. (2004). Age and origin of volcanic ashes in the Bishop Conglomerate, south flank of the Uinta Mountains, Utah. Abstracts with Programs - Geological Society of America, vol.36, no.5, pp.100.
Swanson, B.A. (2003). Sedimentology, stratigraphy and strontium geochemistry of the Eocene Luman Member, Green River Formation, Wyoming. Unpublished Master's Thesis, University of Wisconsin-Madison, Madison, WI, United States (USA) 39pp.