摘要
夏杖子金矿床中矿物包裹体水的氢、氧同位素分别为:δD=-91.7‰——73.1‰,δ^(18)O_(H_2o)=5.68‰—6.23‰,说明读矿床的成矿溶液是来源于岩浆水和大气降水;矿物的硫同位素组成基本上全是负值,且变化范田较小,同位素平衡温度平均为208—240℃,成矿溶液总硫平均同位素组成—19.70‰——20.64‰,证明成矿热液中H_2S原子团占优势,其硫源可能为本区结晶基底;石英中流体包裹体Rb—Sr同位素等时年龄为1054±7.2Ma,说明其成矿时代为燕山晚期。综合分析认为,该矿床为与岩浆热液有关的中—低温热液脉型金矿床。
The oxygen and hudrogen isotopic compositions of inclusion water in Xiazhangzi gold deposit are respectively SD=- 91. 7‰0-73. l/‰and δ18OHgo = 5. 6‰-6. 23‰-The miner-alizing fluids of the deposit come from magmatic and meteoric water With a narrow range of change, the S-isotopic compositions are nearly all minus and the average equilibrium tem-perature varies from 208℃ to 240℃; the average isotopic composition of total sulphur in the mineralizing fluids ranges from -19. 70‰ to -20. 64‰, indicating that atom group H2S pre-vailed in the fluids and the sulphur derived from the crystal basement in this area. The Rb-Sr isotopic isochron value (105±7. 2Ma) of quartz fluid inchusions implies a late Yanshanian mineralization. This deposit is of epi-mesothermal vein type related with magmatic hy-drothermal solution.
关键词
金矿床
同位素
矿床成因
地质意义
gold deposit isotopic composition metallogenic age Hebei Xiazhangzi
