北祁连山西段西柳沟铅锌矿稳定同位素特征

西柳沟铅锌矿位于北祁连山西段以钨、钼、铜、铅、锌等为主的多金属成矿带之西端。为探讨其成矿流体的来源，选择了该矿床主成矿期的9 件矿石样品，挑选其单矿物，并对保存于石英中的原生包裹体做了D, O 同位素分析，分析显示成矿流体的δDV-SMOW 值为-47‰ ~ -72‰；成矿期石英矿物的δ18O 介于11.9‰ ~ 14.1‰之间，与石英平衡的热液水的δ18OH2O‰值为-0.79‰ ~ 3.64‰之间（包裹体均一温度平均值为190℃）；矿体石英包裹体δ13CV-PDB‰值介于-6‰ ~ -4.2‰之间。成矿流体包裹体的均一温度为126℃ ~ 384℃，集中于140℃ ~ 200℃ ；盐度ω （NaCleq）为1.05% ~ 9.86%，多数为1.74%~ 6.45%。研究表明：西柳沟铅锌矿是浅成的中低温、低盐度、低密度岩浆期后热液型矿床，成矿流体来源主要是以岩浆水为主，大气降水为辅。

Stable Isotopic Characteristics of Xiliugou Polymetallic Deposit in the Western Part of the North Qilian Mountains

A polymetallic deposit zone with W, Mo, Cu, Pb, Zn mineralization was found in the western part of the North Qilian Mountains. The Xiliugou polymetallic deposit is located in the western part of this polymetallic deposits zone. In order to discuss the source of ore-forming fluid of this deposit, the authors selected 9 ore samples of the main ore-forming stage from this deposit and measured their H, O, C isotopic compositions. The results show that the DV-SMOW‰ values of the ore-forming fluid are -47‰ ~-72‰ with very small variation. The δ18O values in the main stage vary between 11.9‰ ~14.1‰. The δ18OH2O‰ values of the hydrothermal fluid equilibrated with quartz are -0.79‰ ~3.64‰（ the average homogenization temperature of the fluid inclusions is 190℃）. The δ13C values of fluid inclusions captured in the quartz are -6‰~-4.2‰, also with a small variation range. Microthermometric studies indicate that the homogenization temperatures and salinities of the fluid inclusions in the oreforming stage range from 126 to 384℃ and from 1.05% to 16.45% NaCl equivalent, respectively, with most values in the range of 140~200℃ and 1.74%~6.45% NaCl equivalent, respectively. It is shown that the Xiliugou polymetallic deposit is a shallow, low temperature, low salinity and low density hydrothermal deposit. The magmatic water is the main source of the ore-forming fluid, and the meteoric water is subsidiary.