胶东夏甸金矿区道北庄子金矿床流体包裹体和氢氧同位素地球化学研究

Geochemical Study on Fluid Inclusion and HO Isotope of Daobeizhuangzi Gold Deposit in Xiadian Gold Field in Jiaodong Province

摘要:

夏甸金矿区道北庄子金矿床位于招远平度断裂带中南段。该文重点研究金矿床石英矿物中的流体包裹体和氢氧同位素特征。研究表明，流体包裹体以Ⅰ型富液相包裹体为主，均一温度主要集中在4个区域：100～140℃，160～210℃，220～250℃，300～340℃。与胶东地区金矿成矿的4个阶段相对应。盐度变化范围大致分布在0.88～22.44wt%，平均5.18%，集中分布在3～7wt%，成矿流体盐度为低盐度流体；密度变化于0.62～1.08g/cm3，平均0.91g/cm3，属于低密度流体；成矿压力范围在92.58～267.12MPa，平均149.64MPa，推断矿床成矿压力环境为中压环境；矿床成矿深度范围为6.84～12.65km，平均9.63km，矿床为中深成相。根据氢氧同位素地球化学特征，成矿流体主要为地幔初生水，并受岩浆水的影响。

Abstract:

Daobeizhuangzi gold deposit in Xiadian gold field located in the middlesouth of Zhaoping fault zone. In this paper, fluid inclusions and hydrogenoxygen isotopic characteristics of quartz minerals have been analyzed. It is showed that the fluid inclusions are mainly liquid inclusions, and its homogenization temperature fall into four ranges: 100～140℃,160～210℃,220～250℃ and 300～340℃;corresponding to four stages of hydrothermal oreforming processes of Jiaodong area. The fluid is with low salinity and low density, ranging from 0.88～22.44WtNaCl%(focus on 3～7Wt% with average salinity of 5.18Wt%),and from 0.62～1.08g/cm3 (with average density of 0.91g/cm3 ).The pressure of mineralization is mediumpressure, ranges from 92.58～267.12MPa, with an average pressure of 149.64MPa. The depth of mineralization ranges from 6.84～12.65km, with the average range of 9.63km. It indicate that the ore body is mesozone. According to the characteristics of hydrogenoxygen isotopic, the mineralizing fluids originated mainly from meteoric water and accompanied with participation of magmatic water.