Abstract: Well-preserved Mesoproterozoic chimneys and mounds were recovered from the Gaobanhe SEDEX type polymetallic sulfide deposits in Xinglong, Hebei Province, North China. Electron microprobe measurement shows the chimneys have high gold contents. The highest content of gold among 74 testing points is up to 4560 μg/g. Gold contents in different minerals and different types of pyrite reveal apparent differences. Gold-bearing assemblages are dominated by idiomorphic pyrite, which were formed during the late-stage hydrothermal activity. Analyses of fluid inclusions in calcite, quartz and sphalerite show that precipitation of gold occurred at about 170 ℃, which also represents the lower temperature limit of chimney formation. This study provides direct proof for the relationship of exhalation and gold formation, indicating that gold precipitation is closely related to late-stage, low-temperature hydrothermal fluids.

Key words: seafloor chimneys, SEDEX type sulfide deposits, gold formation, fluid inclusions

摘要： 现代海底黑烟囱具有金矿化的潜力，对于重新认识陆上硫化物的金成矿具有重要意义。本文对河北兴隆中元古代黑烟囱及烟囱内部金矿化进行了系统的研究，提供了喷流作用与金矿化关系的直接证据，矿石微区金最高含量达4560 μg/g。碳酸盐、石英和闪锌矿中流体包裹体的均一温度集中在100～200 ℃之间，代表黑烟囱形成的温度下限，也限定了金沉淀富集的温度范围，烟囱不同矿物和不同结构黄铁矿中含金量存在明显差异，金主要富集于后期形成的自形-半自形黄铁矿中，初步推测该区硫化物中金矿化发生于喷流作用后期，热液在烟囱及丘体内部持续活动，促进金的富集。

关键词: 硫化物黑烟囱, 沉积-喷流作用, 金矿化, 流体包裹体