试论韧性剪切作用与金的成矿
DISCUSSION ON THE RELATIONSHIP BETWEEN DUCTILE SHEARING AND MINERALIZATION OF GOLD
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摘要: 多数学者认为"剪切带型"金矿床的成矿动力和成矿机制均为韧性剪切作用,且进行了大量的实验论证。本文从理论研究和实例分析认为韧性剪切作用本身成矿的可能性不大,"剪切带型"金矿床并非"同剪切型"或"后剪切型"同生矿床,而是"剪切后型"的后生热液矿床,即成矿总是滞后于剪切作用,剪切作用不是成矿,而是创造了成矿的空间,成矿物质主要来自深部或容矿围岩。Abstract: Now it is commonly thought that the ore-forming driving forces and mechanism of shear-zone type gold deposit is the ductile shearing,and lots of experiments have carried out.In this paper the author proposes that the ore-formation of ductile shearing is almost impossible according to theoretical analysis and field examples.A ductil shear-zone type gold deposit is just epigenetic hydrothermal deposit of after-shearing type,not a syngenetic deposit of syn-shearing or post-shearing type.The mineralization always delays to the ductile shearing,the ore-forming material mainly comes from the depth or host rock,so shear-zone type deposit is only a descriptive terminology,and has no genetic meaning.