摘要
在对荡坪钨铍热液矿床晶洞水晶作温压地球化学特征研究的基础上 ,对该水晶第 1和第 6切块的核部与其边缘环带氧及其原生流体包裹体中碳、氢、氧同位素组成进行系统研究。研究表明 ,晶体核部富集1 8O (δ1 8OQ 值 12 .1‰～ 12 .9‰ )→边缘环带相对贫1 8O (δ1 8OQ 值 7.6‰～ 8.2‰ ) ;核部的流体为岩浆水 (δ1 8OH2 O值 + 4 .7‰～ + 6 .2‰ )→边缘环带为大气降水 (δ1 8OH2 O值 - 6 .1‰～ - 8.4‰ ) ;水晶原生流体包裹体δDH2 O和δ1 8OH2 O值由核部→边缘环带逐渐降低 ,δ1 3 CCO2 值则升高。认为形成水晶的成矿流体来自岩浆期后热液 ,结晶晚期则以大气降水为主 ;水晶是在相对开放的系统中结晶形成的 ;高温和低温条件下形成的水晶 (SiO2 )中氧与其包裹体H2 O中的氧可发生同位素交换。
Based on research of fluid inclusion thermobarogeochemical features of a mega quartz crystal,systematic study has been carried out on carbon, hydrogen and oxygen isotope compositions of primary fluid inclusions from first and sixth sections of the crystal. The data show that (1) the 18 O is rich in the core (δ 18 O=12.1‰～12.9‰) and poor in the rim (δ 18 O=7.6‰～8.2‰) of the crystal; (2)fluid inclusions in the core came from magmatic water(δ 18 O H 2O =4.7‰～6.2‰) and these in the rim belong to atmospheric water(δ 18 O H 2O =-6.1‰～-8.4‰); (3)the δD H 2O and δ 18 O H 2O decrease and δ 13 C CO 2 increase from the core to rim of the crystal. So, it is concluded that metallogenetic fluids came from high temperature post magmatic hydrothermal solution during the early stage and mainly from atmospheric water during the late stage of crystallization and that the crystal grew in a relatively open system where effective oxygen isotopic exchange happened between crystal and its fluid inclusions.
出处
《华南地质与矿产》
CAS
2000年第2期1-5,共5页
Geology and Mineral Resources of South China
基金
国家自然科学基金项目!"成矿流体中的羧酸"(No .496 73193)的部分成果
关键词
稳定同位素地球化学
水晶
流体包裹体
钨铍矿床
stable isotope geochemistry quartz crystal fluid inclusion Dangping tungsten beryllium deposit Jiangxi province
