岩がん圏けんがんけんMeanings1nounlithosphererare termgeologyRare geology term for the Earth's rigid outer layer. The synonym 岩石圏 (がんせきけん) is more common.See also: 岩石圏岩がん圏けんは地ち殻かくと上じょう部ぶマントルからなる。The lithosphere consists of the crust and the upper mantle.