摘要
对西安里铁矿床蚀变矿物(透辉石、石榴子石、绿帘石和方解石)流体包裹体进行了岩相学、均一温度、盐度和H-O同位素组成分析研究,结果表明:透辉石中流体包裹体均一温度为515℃～622℃,盐度(w(NaCl))为48～75;石榴子石均一温度为475～525℃,w(NaCl)均小于26wt%NaCl;绿帘石均一温度为390～440℃,盐度主要分布在40 wt%NaCl左右;方解石均一温度为141～4066℃,w(NaCl)为6.74～21.11;石榴石、透辉石的δD SMOW值介于-106‰～-86‰,δ18O SMOW值介于6.7～8.7‰,δ18O H2O值介于2.7‰～8.7‰。磁铁矿δ18O H2O值介于2.6‰～6.2‰。综合分析认为:热液主要来源于岩体,在上升过程中萃取了围岩中Na和Cl,Na的加入使大量Fe析出,并与Cl结合进行迁移,流体物理化学特征具有显著的变化,导致Fe质析出形成西安里铁矿床。
This work studies the fluid inclusions from altered minerals （ diopside, garnet, epidote, and calcite） in the Xi＇ anli iron deposit of Shanxi Province based on their petrography, homogenization temperature, salinity, and H - O isotopic compositions. The results show that homogenization tem- perature of the fluid inclusions in diopside varies from 515℃ to 622℃, and their salinity is between 48 and 75. Fluid inclusion homogenization tempera- ture of garnet is from 475℃ to 525℃ , with w（NaC1） less than 26 wt%. Fluid inclusion homogenization temperature of epidote is in 390 N440℃ , with salinity 40wt% NaC1. Fluid inclusion homogenization temperature and salinity of calcite are in the rang of 141 - 4066- with 6.74 -21. l lwt% NaC1. δDsMow of garnet and diopside ranges from -106‰ to -86‰, BlSOsmow ranges from 6.7 to 8.7‰, and δ18 OH20 from 2. 7‰ to 8. 7‰. BIs OH2o of magnetite is from 2.6‰ to 6.2‰. The synthetic analysis suggests that the hydrothermal fluid mainly originated from rock mass. During the rising process, the magmatic hydrothermal solution extracted Na and CI from surrounding rocks. The addition of Na resulted in the precipitation of much Fe, and made Fe combine with C1, and then migrate. The significant variations of physical and chemical properties led to the precipitation of Fe and the formation of the Xi＇ anli iron deposit.
出处
《地质与勘探》
CAS
CSCD
北大核心
2014年第1期67-76,共10页
Geology and Exploration
基金
国家自然科学基金(编号41040020
41073027)
中国地质调查局项目(编号1212011121076)
中央高校基金(编号CHD2011ZY005
CHD2011JC168)资助
关键词
西安里铁矿床
成矿流体特征
钠化蚀变
H-O同位素
Xi＇ anli iron deposit, characteristics of ore-forming fluids, natriumzation, H - 0 isotopes
