Amygdales in the volcanic series of the Xiong''''er Group on the southern margin of the North China plate:evidence of hydrothermal mineralization

Amygdales with distinct features are prevalent in mineralized sites in the Xiong'er Group vol-canic rocks on the southern margin of the North China plate.Some amygdales even have developed into mineralized bodies.However,previously this phenomenon was less studied.Based on a systematic study of the textures and structures of amygdales and their filling minerals,the formation mechanism of amygdales and their relationships with hydrothermal ore fluids and ore-forming processes are discussed in details in the paper.Finally,the authors point out that amygdales are an important indicator of exploration in the Xiong'er Group volcanic rocks on the southern margin of the North China plate.