广西古袍金矿区花岗斑岩侵入期后多期热液成矿作用的Ar-Ar年龄证据

Isotopic Evidence for Multi-stage Ore-forming Processes after the Intrusion of Granite Porphyry in the Gupao Gold Ore District, Guangxi

古袍矿区的花岗斑岩出露于古袍复向斜西部扬起部位。围岩地层主要为寒武系水口群浅变质砂岩、粉砂岩、硅质岩及板岩、千脉岩和碳质页岩。花岗斑岩和花岗斑岩内的石英脉体中石英样品的^40Ar／^39Ar年龄数据表明，^40At／^39Ar坪年龄值在187．87±1．53Ma至244．88±2．48Ma之间，是加里东期花岗斑岩成岩作用之后，海西、印支或者燕山早期多期构造热液作用的产物。金矿化与花岗斑岩成岩后的多期次构造热液作用有关。主要受控于断层破碎带及其中充填的石英脉和黄铁矿化。

Granite porphyry stocks in the Gupao gold ore district are located in the west of Gupao synclinorium. The country rocks are mainly a suite of slightly metamorphosed sandstone, siltstone, siliceous rock, slate, phyllite and carbonaceous shale in Cambrian Shuikou Group. ^40Ar/^39Ar data of quartz from the granite porphyry and from the quartz veins in the granite porphyry range from 187.87 ± 1.53 Ma to 244.88 ± 2.48 Ma, indicating products of structural hydrothermal fluids of Late Hercynian, Indosinian or Early Yanshanian periods. Gold mineralization is related to the activity of the multi-stage structural hydrothermal fluids after the intrusion of the granite porphyry, and controlled by the quartz veins and pyritization that fill the fault zones.