老挝北部爬奔金矿床成矿作用及成矿模式

Metallogenic Process and Model of the Phapon Gold Deposit in the Northern of Laos

爬奔金矿位于琅勃拉邦-黎府华力西褶皱带北段,属特提斯构造域东段与西太平洋构造域交接地带。通过对爬奔金矿区域地层成矿元素及各类矿石元素含量分析,确定石炭-下二叠统灰岩为金矿床的矿源层,金的迁移以氯的络合物形式进行迁移,进一步研究矿床稀土元素、稳定同位素、流体包裹体等测定结果,认为爬奔金矿成矿物质来源复杂,具岩浆热液和大气降水双重来源,从含矿流体递进演化显示含矿流体起源与演化的各种形态的方解石脉体都在下二叠统灰岩中。综合分析认为,爬奔矿床成矿热液流体的形成是剪切作用下岩石压溶的结果,在此基础上提出了爬奔金矿床的成矿模式。

Phapon gold deposit is located in the northern part of Luangprabang-Loei Varisian fold belt,which lies in the connection of eastern Tethys tectonic domain and western Pacific tectonic domain.Through the analysis to the content of elements in the regional stratum and in the ores,it is concluded that Carboniferous-lower Permian limestone is the source layer of mineralization,and gold migrates as chlorine complex.Through the further study to rare earth elements,stable isotope and fluid inclusion,it is suggested the metallogenic material origins dually from magmatic hydrothermal fluid and meteoric water.The evolution of matallogenic fluid shows that various calcite veins formed during the evolution are all in Permian limestone.As a whole,the metallogenic hydrothermal fluid is the result of rocks pressure solution under the shear action.The metallogenic pattern of Phapon gold deposit is proposed on the basis of this conclusion.