Oolites are most commonly found in limestones, dolomites, or iron ores. Their occurrence in shale has not been recorded, as far as the writer is aware. The oolites described in this paper are found in a shale member of the red beds of the Wind River Mountains near Lander, Wyoming.
These red beds of Wyoming owe their name to their prevailing color. They consist of a series of shales, sandstones, thin beds of limestone and dolomite, and some lenticular beds of gypsum. The various beds show all degrees of gradation into one another, the majority being somewhat calcareous. The shales are often sandy and the sandstone may contain some argillaceous material. The limestone and dolomite beds are, however, quite pure. As this formation is very poor in fossils, its age is still a matter of conjecture. Paleontologie work by Williston2 and Branson3 show that the upper portion at least is