冀东-辽西地区喜峰口-叨尔登金成矿带的成矿机理

THE MINERALIZATION MECHANISM OF THE XIFENGKOU-DAOERDENG GOLD METALLOGENIC BELT IN EASTERN HEBEI AND WESTERN LIAONING

喜峰口-叨尔登金成矿带上的金矿床产出空间各不相同,矿床的围岩有花岗岩、变质岩及沉积岩.矿体的分布均受控于断层破碎带,矿床成因与热液有关.通过对铅、硫以及包裹体水同位素的研究,确定了金矿在成矿时间上与燕山期花岗岩一致,成矿热液中的水主要来源于花岗岩,成矿物质黄铁矿中的硫来源于花岗岩.因此说明研究区的金矿为燕山期花岗岩期后热液成因.产于地壳深部的富含成矿物质的花岗岩浆在上侵过程中同化了部分太古宙变质岩并从中汲取了成矿物质,将其带到地壳浅部,最后沿构造裂隙充填成矿.

The gold deposits in the Xifengkou-Daoerdeng metallogenic belt occur in different rocks such as granite, metamorphic rocks and sedimentary rocks. The orebodies are distributed in fault zones and related with hydrothermal fluids. Based on the Pb-S-O-H isotopic data, the gold deposits were formed consistently with Yanshanian granite. The hydrothermal fluids were derived from the granite. Thus the sulfur in pyrite was sourced from the granite. In summary, the gold deposits are post-granite hydrothermal deposits. The granite extracted ore-forming materials from some Archean metamorphic rocks during intrusion, then transported them to shallow level of the crust and deposited in the structural fractures.