Taking another look at Utah's tar sand resources

Recent increases in the price of crude oil have sparked renewed interest in unconventional energy resources, including Utah s tar sands. Tar sands (also called oil-impregnated sandstones, oil sands, and bituminous sandstones) are, as the names imply, sandstones that are saturated or filled with black, heavy hydrocarbons or bitumen. The sandstone can be unconsolidated, that is, the sand grains are held together mainly by the bitumen, or it can be consolidated, whereby the sand grains are held together by silica or carbonate cement with the bitumen filling the remaining voids. The bitumen is viscous, relatively immobile in the rock, and cannot be extracted by conventional oil-production techniques. The bitumen often bleeds from outcrops that are warmed by the sun, however