小岩体成大矿与岩浆通道成矿理论的比较

Comparison of Theories Between Large Orebodies Hosted in Small Intrusion and Magma Conduit Mineralization

从小岩体成大矿和岩浆通道成矿理论的提出、发展、完善及其主要成矿控制因素展开探讨,结合典型矿床实例,指出这两种理论在勘查实践中的贡献和应用价值,并比较其异同点。小岩体成大矿与岩浆通道成矿理论的主要区别在于:小岩体成大矿理论中岩浆管道与岩浆通道成矿理论并非同一概念;深部熔离预富集是前者的主要控制因素;前者是硫化物深部熔离-脉冲式贯入占主导,而后者是硫化物就地熔离-局部聚集为主;在硫化物熔离机制方面,后者要求外来硫的加入是必需条件,而前者认为外来硫的加入并非不可或缺,在岩浆深部就可以发生硫化物不混溶作用;在成矿物质聚集方式上,后者认为含矿岩浆分凝和上侵是连续过程,而前者则强调岩(矿)浆上侵是脉动式过程。在找矿实践过程中要重视小岩体,并注重含矿小岩体的下盘和岩浆上升的管道位置,这些地区是扩大区域找矿前景、增加资源储量最具潜力的部位。

The theories of large orebodies hosted in small intrusion and magma conduit mineralization were introduced;the development and main metallogenic controlling factors of the two theories were discussed;combined with the typical magmatic Cu-Ni deposits,the applications of the two theories for prospecting and exploration practice were summarized;and the two theories were compared. The differences between the two theories of large orebodies hosted in small intrusion and magma conduit mineralization include that the concept of magmatic pipe for the former is different from that for the latter;deep liquation and preconcentration is main controlling factors of the former;is the main mineralization features are deep liquation-pulsed penetration of sulfide for the former, and in-situ liquation and partial concentration of sulfide for the latter;for the mechanism of sulfide liquation,extrinsic sulfur is requirement for the latter,but extrinsic sulfur is optional for the former,and sulfide immiscibility occurs in the deep of magma;for the concentration of ore-forming materials,the progresses of segregation and intruding of ore-bearing magma are continuous for the latter,but the progresses of intruding of magma or pulp are pulsed for the former.The small intrusion is important for prospecting and exploration practice;the footwall of ore-bearing small intrusion and pipe position of＆amp;nbsp;magmas rising are paid attention to;all of them have the greatest potential for enlarging the prospecting prospect and increasing resources reserves of magmatic Cu-Ni sulfide deposits.