Named for Yellow Creek in the Barcus SE quad, Rio Blanco Co, CO. Type section measured in NE1/4 SE1/4 sec 13, T1N, R98W in the Piceance basin. Designated a tongue of Green River Formation that overlies and underlies Uinta Formation. Previously mapped as part of Parachute Creek Member of Green River. Is mostly marlstone (37 ft of the 45 ft section) at the type. Marlstone is light brown gray, and variably silty. Interbedded siltstone is light gray to brown gray, calcareous to marly, and has wavy bedding. Interbedded sandstone is light gray, fine to medium grained and calcareous. Ranges from 0-77 ft thick. Is assigned an Eocene age.
Source: GNU records (USGS DDS-6; Denver GNULEX).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
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