Geochemistry of Oil-Shale Genesis, Green River Formation, Wyoming

The world's largest oil-shale deposit is the Tertiary Green River Formation in Colorado, Utah, and Wyoming. All of the world's oil shales formed in lakes or marine embayments under conditions tending to preserve organic matter in the sediment. Although few of the world's deposits of oil shales yield most of their organic matter as shale oil on heating, the Green River formation oil shales yield 65 to 70% of their organic matter as oil. This high conversion to oil probably reflects the high proportion of available hydrogen in the Green River oil shale's organic matter. Wyoming's Green River Formation contains much oil shale. Culbertson has estimated that Wyoming's part of the formation represents 370 billion bbl of shale oil in place. This report postulates geochemistry of the depositional conditions which produced Wyoming's huge deposit of hydrogen-rich oil shale. (13 refs.)