摘要
新疆两棵树铁矿位于阿尔泰南缘克朗盆地,矿床赋存于中-上泥盆统阿勒泰镇组片岩与二长花岗岩接触带的伟晶岩中。本文对矿石中石英流体包裹体进行显微测温分析,结果显示包裹体类型以液体包裹体为主,流体的均一温度变化于156～367℃,主要集中于210～250℃,成矿流体盐度w(NaCleq)为0.18%～18.72,密度为0.80～0.95 g/cm3,表明成矿流体属中温度、低盐度、中低密度的H2O-NaCl体系。石英的δDSMOW为-110‰～-76‰,δ18OSMOW为5.3‰～7.9‰,δ18OH2O为1.03‰～1.07‰,表明成矿流体来源于岩浆水,混合大气降水;成矿时代为中泥盆世(约377 Ma),成矿作用与二长花岗岩的侵入有关;温度和压力的降低、流体混合、水岩反应等在铁成矿过程中起着主导作用。
The Liangkeshu iron deposit in Xinjiang is located in the Kelang basin at the southern margin of Altay. The iron deposit occurs in pegmatite dikes at the contact zone of monzonitic granite and schist of the Middle-Upper Devonian Aletai Formation. Fluid inclusions in quartz from the ore body, which are mainly liquid inclusions were studied by micro temperature measurement and are described in this paper. The results indicate that the homogenization temperatures of the fluid inclusions varied from 156℃ to 367℃, mostly distributed from 210℃ to 250℃. The salinity （NaCleq） of fluids ranged from 0.18% to 18.72% and the densities ranged from 0.80 g/cm3 to 0.95 g/cm3. Ore fluids in the Liangkeshu iron deposit were characterized by medium temperature, low salinity and low density, and belonged to the H20-NaC1 system, tSDsMow values of quartz were from - 110%o to -76%0, δ^18SOSMOW values changed from 5.3‰ to 7.9‰ and δ^18OH2O values varied from 1.03‰ to 1.07‰, implying that the ore-forming fluid was magmatic water mixed with meteoric water. Fe mineralization in the Liangkeshu deposit occurred in the Middle Devonian period （about 377 Ma） , and is closely related to the monzonitic granite. The decrease of temperature and pressure, the fluids mixing and water-rock reaction played important roles in ore- forming processes of the Fe ore bodies.
出处
《岩矿测试》
CAS
CSCD
北大核心
2013年第2期340-347,172,共8页
Rock and Mineral Analysis
基金
国家科技支撑计划项目(2006BAB07B02-01,2011BAB06B03-02)
中国地质大调查项目(1212011220894)
关键词
阿尔泰两棵树铁矿床
伟晶岩型铁矿
流体包裹体
氢氧同位素特征
Liangkeshu iron deposit in Altay Region
pegmatite iron deposit
fluid inclusions
hydrogen andoxygen isotopic charactristics
作者简介
耿新霞，助理研究员，主要从事成矿规律及遥感找矿研究。E—mail：gengxinxia0536@sina．com。
