Science / Geology / Oil Shale: A dark-colored shale containing an unusual amount of solid organic material known as kerogen. This shale can be crushed and heated to liberate gaseous and liquid hydrocarbons. At present the expenditure required to process oil shale into a fuel makes this effort marginally profitable or unprofitable.
Science / Geology / Crude Oil: A liquid hydrocarbon produced from natural underground reservoirs. It might also include liquid hydrocarbons produced from tar sands, gilsonite, and oil shale. Crude oil can be refined into a number o MORE
Science / Geology / Shale: a clastic sedimentary rock that is made up of clay-size (less then 1/256 millimeter in diameter) weathering debris. It typically breaks into thin flat pieces. Picture of Shale. MORE