Composition and origin of the Uinta Basin bitumens

The names of the three formations of interest, from oldest to youngest, the Wasatch, Green River, and Uinta, have been used largely as facies terms to differentiate sediments which were believed to be of different age but actually were deposited simultaneously. The Wasatch is predominantly fluviatile and continental, consisting of redbeds and thick sands. Much of what has been called Wasatch in the cliffs along the south side of the basin was deposited at the same time as what has been called Green River in the center of the basin. The Green River includes those beds of lacustrine lithologic type, of which the most distinctive are the oil shales. The Uinta formation, red and green shales and channel sands, is well developed in the northeastern part of the basin and grades into lacustrine beds which have been called Green River toward the center. In this paper the terms Wasatch, Green River, and Uinta are used to designate timestratigraphic units, unless it is expressly stated that they are used as facies terms by some phrase like "Green River lithology."