THE MAIN MINERALIZATION MECHANISM OF MAGMA SULFIDE DEPOSITS IN CHINA
Tang Zhongli(Gansu Bureau of Geology and Mineral Resource, Lanzhou, Gansu)
The meaning of "the deep-seated magmatic liquation-injection mineralization" is as follows. Before intruding, parent magma has undergone liquation and partial crystallization at depth, so that the parent magma is partitioned into barren magma, ore-bearing magma, ore-rich magma and ore pulp, which then ascend and inject into the present locations once or multiple times, thus forming deposits. The volume of the barren magma is generally much larger than those of the ore-bearing magma, ore-rich magma and ore pulp. In the ascending process, the barren magma mostly intrudes into different spaces or outpours onto the surface, forming rock bodies or rock flows. The rest barren magma, ore-bearing magma, ore-rich magma and ore pulp may multiple times inject into the same space where lithogenesis and mineralization take place (e. g. Jinchuan), or may separately inject into different spaces where lithogenesis and mineralization happen (e. g. Hongqiling). Compared with in-situ magmatic liquation deposits, deep-seated magmatic liquation-injection deposits have a much smaller volume, higher ore yield and higher ore grade. Consequently, this mineralizing process results in the formation of small rock masses and large deposits.