小秦岭中矿带金矿田成矿构造分析

Analysis on the Mineralization Structure of Gold Orefield in Xiaoqinling Midle-orebelt

小秦岭金矿田中矿带是在老鸦岔背形翼部韧—脆性剪切带的基础上由含矿流体贯入形成的含金石英脉,其不仅延伸较长、延深较大,而且矿脉较宽,展布有文峪、东闯、杨寨峪、长安岔和金硐岔等大中型金矿。在概述成矿地质背景、归纳矿脉地质特征的基础上,分析了该区成矿地质作用,认为成矿流体主要来自深源,通过地幔热柱多级演化,贯入到早期韧—脆性剪切带中积聚结晶,形成一条或多条规模较大的含金石英脉,甚至出现研究区主矿脉所占有的金属储量超过矿区50%～90%的金属储量的现象。在今后的工作中,建议不要依据矿权的划分来评价矿床规模,而应根据矿脉的自然展布来统筹评价矿床规模,包括指导矿区深部和外围勘查工作。

The middle belt of Xiaoqinling gold field is ore-bearing fluid penetration ductile and brittle shear zone of Laoyachan antiform wing formation of auriferous quartz veins.It is not only of long extension, larger extending and wide veins.Distribution has large and medium-sized gold mine of Wenyu, Dongchuang,Yangzhaiyu, Chang＇ an- cha,Jindongeha and other.We reviews background of metallogenic geological,analyze the characteristics of ore- controlling structures, discuss the ore-forming.The studies indicate that ore-forming fluid comes mainly from deep source,through the multistage evolution of mantle plume,penetration to the ductile shear zone of accumulation and mineralization, formation of gold-bearing quartz veins.Even a mother lode gold reserves to the whole mining area from 50% to 90%.We recommended not to evaluate the scale of ore deposits according to mining right,but to the natural distribution, including guiding mining deep and peripheral prospecting.