rock+oil
131Oil shale geology — Main article: Oil shale Outcrop of Ordovician kukersite oil shale, northern Estonia. Oil shale geology is a branch of geologic sciences which studies the formation and composition of …
132rock — rock1 rockless, adj. rocklike, adj. /rok/, n. 1. a large mass of stone forming a hill, cliff, promontory, or the like. 2. Geol. a. mineral matter of variable composition, consolidated or unconsolidated, assembled in masses or considerable… …
