Oil shale of the Uinta Basin, northeastern Utah

The Tertiary rocks, which occupy the interior of the Uinta basin, have been subdivided into four formations: Wasatch, Green River, Bridger, and Uinta. The division is based on stratigraphic and paleontologic evidence. Hydrocarbon materials have been found in all four formations, although bedded deposits (asphaltic sandstone and oil shale) are known only in the Wasatch and Green River. Veins of gilsonite, elaterite, ozocerite, and other related hydrocarbons cut all the Tertiary formation of the Uinta basin. Good oil shale (Uinta basin of Utah) is black or brownish black except on weathered surfaces, where it is blue-white or white. It is fine grained, slightly calcareous, and usually free from grit. It is tough and in thin-bedded deposits remarkably flexible. Although oil shale consists of thin laminae, this is not apparent in some specimens until after the rock has been heated and the oil driven off. Freshly broken oil shale gives off a peculiar odor similar to that of crude petroleum. Oil shale contains a large amount of carbonaceous matter (largely remains of lower plants, including algae), which is the source of the distillation products. Thin splinters of oil shale will burn with a very sooty flame and give off an asphalticmore » odor. Lean specimens of oil shale have a higher specific gravity than rich specimens and are generally heavier than coal.« less