摘要
采用质谱分析等方法,测试了夏枚子金矿床石英流体包裹体和金属硫化物的同位素组成,获得石英流体包裹体Rb-Sr等时线年龄为105.4±7.2Ma;锶同位素初始比值为0.7126±0.0001;氢同位素组成δD‰为-91.7～-73.1;氧同位素组成δ^(18)OH_2O‰为5.68～6.23;金属硫化物的硫同位素组成δ^(34)S‰=-23.38～-14.52;铅同位素组成^(206)Pb/^(204)Pb=16.441～16.615,^(207)Pb/^(204)Pb=15.228～15.256,^(208)Pb/^(204)Pb=36.268～36.356。矿床成矿作用发生于燕山晚期,成矿热液主要为岩浆热液,金矿成矿物质来源于硅铝壳中下部太古代结晶基底,矿床成因是与燕山期岩浆热液有关的中—低温热液脉状金矿床。
Through spectrometric analysis and the other methods the determina-tion of isotope compositions of quartz fluid inclusions and metallicsulfides in the Xiazhangzi gold deposit is made. It is indicatedthat for quartz fluid inclusions: the Rb-Sr isochronic age is 105.4±7.2 Ma, the initial ^(87)Sr/^(86)Sr isotope ratio is 0.7126±0.0001, thehydrogen isotope compositions range from -91.7‰ to -73.1‰, the oxygenisotope compositions range from 6.58‰ to 6.23‰ and for metallic sulfides:the sulfur isotope compositions range from -23.38‰ to -14.52‰, ^(206)Pb/^(204)Pb range from 16.441 to 16.615,^(207)Pb/^(204)Pb range from 15.228 to 15.256and ^(208)Pb/^(204)Pb range 36.268 to 36.356. It is shown that mineralization ofthe gold deposit is formed during Late Yanshanian. The forming solutiondominantly is magmatic. The ore-forming materials of gold are derivedfrom the Archaeozoic crystalline hasement of the lower and middle sialiccrust. The gold deposit is Yanshanian intermediate-low-temperaturehydrothermal vein-like one related to magmatic solution in origin.
关键词
金矿床
同位素地质学
铷
锶
年龄
gold deposit
isotope geology
Rb-Sr age
Hebei
