oil shale

noun

Geology.

1. a black or dark-brown shale or siltstone rich in bitumens, from which shale oil is obtained by destructive distillation.

oil shale

noun

1. a fine-grained shale containing oil, which can be extracted by heating

oil shale

1. A fine-grained black or dark brown shale containing hydrocarbons in the form of kerogen. When heated, oil shale yields petroleum or natural gas.

Word History and Origins

Origin of oil shale¹

First recorded in 1870–75