摘要
千鹅冲钼铅锌矿床位于东秦岭—大别山钼多金属成矿带,矿体主要赋存于隐伏花岗岩体外接触带的地层中。在整理前人资料和勘查成果的基础上,通过分析千鹅冲钼铅锌矿床的成矿地质作用、成矿岩体化学特征、控矿因素及围岩性质,建立了矿床成矿模式。分析认为:大别山区格子状构造不仅控制着造山带的分布,也对钼矿床的形成和分布起到了决定性作用;成矿地质体高硅、高钾、富碱的地球化学特征有利于钼的成矿;成矿地质体亏损Ba、Nb、Ta、Y和Yb,富集Rb、Th和K等大离子亲石元素,Sr与Y含量低反映岩浆源区的分馏明显;斑岩型钼矿围岩的物理性质对钼矿体沉淀成矿的具体位置有制约作用。初步认为千鹅冲钼铅锌矿床的成矿模式为下元古界大别高压麻粒岩在下地壳重熔形成岩浆岩,在中生代中国东部的构造体制转换下,冷凝的岩浆受热重新活化运移上侵,在压力和温度降低、pH值变化等多种沉淀机制作用下,成矿流体在围岩的节理、裂隙中迁移、沉淀成矿,铅锌矿化多分布在钼矿体外侧。
Qian’echong Mo-Pb-Zn deposit is located in the Mo polymetallic metallogenic belt of East Qinling-Dabie Mountain,and the orebodies mainly occurred in the external contact of the concealed granite.The metallogenic model was proposed through analysis of the mineralization geological process,geochemical characteristics of metallogenic rocks,ore-controlling factors and wall-rock lithology in Qian’echong Mo-Pb-Zn deposit,based on previous data and exploration results.It is concluded that the lattice structures in Dabie Mountain controls the distribution of orogenic belt,and has decisive effect on the distribution and formation of molybdenum ore deposits.The metallogenic geological body,with geochemical characteristics of high silicon,high-potassic,high alkali,is beneficial for the molybdenum mineralization.And the metallogenic geological body is depleted in Ba,Nb,Ta,Y,and Yb,and enriched in large ion lithophile element of Rb,Th and K.The low contents of Sr and Y reflect a high degree of magmatic differentiation.The surrounding rock physical property of porphyry molybdenum deposit shows a certain restriction on the location of molybdenum ore-formation zone.The metallogenic model of Qian'echong Mo-Pb-Zn deposit is the magma rocks remelting in the lower crust from Paleoproterozoic Dabie high-pressure granulite.The condensed magma was activated to the upward migration when it has been heated under Mesozoic tectonic regime transition of East China.Under different precipitation mechanisms of pressure and temperature reduction and pH change,the ore-forming fluid migrates in the fracture zone cracks and rock fractures,and precipitates into mineralization.The Pb-Zn mineralization is well deve-loped outside the molybdenum orebodies.
作者
骆亚南
余少华
王雷
LUO Ya’nan;YU Shaohua;WANG Lei(No.3 Institute of Geological and Mineral Resources Survey,Henan Geological Bureau,Henan Xinyang 464000,China)
出处
《中国地质调查》
CAS
2023年第1期37-44,共8页
Geological Survey of China
基金
河南省两权价款地质科研项目“大别山铜钼金银铅锌成矿系统与成矿预测研究(编号:豫国土资函[2015]258号11)”资助。
关键词
成矿作用
成矿地质体
千鹅冲钼铅锌矿床
成矿模式
mineralization
metallogenic geological body
Qian’echong Mo-Pb-Zn deposit
metallogenic model
