Noun
shale from which oil can be obtained by heating
Source: WordNetA deposit of cement was formed after an occurrence of oil shale located adjacent to a bed of limestone burned due to natural causes. Source: Internet
As with all oil and gas resources, analysts distinguish between oil shale resources and oil shale reserves. Source: Internet
At the same time, the organic matter in oil shale has an atomic ratio of hydrogen to carbon (H/C) approximately 1.2 to 1.8 times lower than for crude oil and about 1.5 to 3 times higher than for coals. Source: Internet
A critical measure of the viability of oil shale as an energy source lies in the ratio of the energy produced by the shale to the energy used in its mining and processing, a ratio known as "Energy Returned on Energy Invested" ( EROEI ). Source: Internet
Biochemical sedimentary rocks Outcrop of Ordovician oil shale ( kukersite ), northern Estonia Biochemical sedimentary rocks are created when organisms use materials dissolved in air or water to build their tissue. Source: Internet
Demand is rising rapidly due to industrial use of guar gum in hydraulic fracturing ( oil shale gas ). Source: Internet