Geology and petroleum resources of the major oil-impregnated sandstone deposits of Utah

Near surface, oil-impregnated rock deposits in Utah are estimated to contain as much as 29 billion barrels of petroleum. Over fifty individual deposits have been identified, primarily through field mapping. Over 96 percent of the oil in place occurs in sandstone host rocks in six giant deposits. Four of the deposits occur in the Uinta Basin of northeastern Utah, and contain petroleum which probably originated in the Green River Formation (Eocene). Three of these deposits, P. R. Spring, Hill Creek, and Sunnyside, also occur in the Green River Formation, but the Asphalt Ridge deposit occupies only older and younger strata. Two deposits occur in marine and marginal marine strata in the dissected plateau region of southeastern Utah. The Tar Sand Triangle is the largest deposit in the state, and occurs in the White Rim Sandstone (Permian). Circle Cliffs is a giant, low-grade deposit in sandstone and siltstone of the middle Moenkopi Formation (Triassic). The oil-impregnated sandstone bodies of the deposits are of variable number, thickness, and petroleum content, and occur under the influence of a variety of structural and topographic conditions. Tables provide summaries of various characteristics of the petroleum and the reservoir strata.