岩がん脈みゃくがんみゃくMeanings1noundike; dykeGeological term for a sheet of rock that formed in a fracture in a pre-existing rock body.この地ち域いきには、玄げん武ぶ岩がんの岩がん脈みゃくが多おおく見みられる。Many basalt dikes can be seen in this area.