摘要
延边地区小西南岔富金斑岩铜矿床的H、O、C、S和Pb同位素特征如下:δ18OQ-H2O为-0.1‰^+5.6‰、δD为-77‰^-38‰,δ18OCc-H2O为-4.3‰、δD为-62‰;石英流体包裹体的δ13CCO2为-5.6‰^-3.5‰,1δ8OCc-H2O为-4.3‰^+11.39‰、1δ3CPDB为-8.8‰^-5.3‰,3δ4S集中在+2.1‰^+4.8‰之间,206Pb/204Pb=18.103~18.3882、07Pb/204Pb=15.405~15.5902、08Pb/204Pb=37.888~38.184,μ值为8.52~8.79。其中:S同位素特征指示含矿流体与次大陆岛弧岩浆相似,而C、O、Pb同位素则指示初始地幔源。结合H、O同位素的地幔初生水+岩浆水+变质水和演化过程向雨水热液和海水方向进行的特征初步认为,初始含矿流体的热动力源是原始地幔,成矿物质来源于I MORB性质地幔,含矿流体演化的浅部过程受到一定程度的雨水热液的混染作用。
The authors present hydrogen, oxygen, carbon, sulfur and lead isotope compositions of the Xiaoxinancha gold-bearing porphyry copper deposits, Yanbian. The concentrations of δ^18 Oquartz-water δD and δ^13 CCO2 trapped in quartz and fluid inclusions of the ores are - 0. 1‰ to ＋ 5.6‰, - 77‰ to -38‰ and -5.6‰ to -3.5‰, respectively. And the δ^18 Ocalte-water and δD of calcite are -4.3‰ and -62‰. In addition, concentrations of δ^18OCc, δ^13CPDB, δ^34S trapped in calcites and sulphides are -4.3‰ to ＋11.39‰, -8.8‰ to -5.3‰, and ＋2. 1‰ to ＋4.8‰, respectively. ^206Pb/^204Pb, ^207Pb/^204Pb, ^208Pb/^204pb ratios are 18. 103 to 18. 388, 15. 405 to 15. 590, 37. 888 to 38. 184 respectively with μ value varying from 8.52 to 8.79. The sulfur isotopic characteristics indicate that the ore-forming fluids are similar to those of subcontinental island arc magmas, the oxygen-carbon and the lead isotopic data reveal a primitive mantle source,and the hydrogen-oxygen isotopic features show a complex fluid of the primary mantle,magmaticand metamorphic water, and with an evolutionary trendency towards meteoric and sea waters. So the authors suggest that the thermodynamic sources were derived from the primitive mantle, the ore-forming fluids had been contaminated by meteoric hydrothermal system on the upper crust or near the surface during ascending, and the ore-forming materials （such as Cu and Au） were from I-MORB mantle.
出处
《吉林大学学报（地球科学版）》
EI
CAS
CSCD
北大核心
2005年第5期601-606,共6页
Journal of Jilin University：Earth Science Edition
基金
国家自然科学基金项目(40472050)
中国科学院地质与地球物理研究所矿产资源研究重点实验室资助
关键词
H
O
C
S
PB同位素
流体起源与演化
富金斑岩铜矿床
延边地区
H,O,C,S,Pb isotope
the genesis and evolution of ore-bearing fluids
gold-bearing porphyry copper deposit
Yanbian area
