摘要
本文研究银洞沟铅锌-银矿床流体包裹体的特征、均一温度、盐度和流体成分,对矿床形成的温度、压力、矿化流体性质及其演化规律等成因问题作出了解释。
Detailed study of fluid inclusions from the Yindonggou Pb-Zn-Ag deposit which occurs in the center of a volcanic rise and closely related to the later rhyolite intrusion has been carried out and the results are presented as follows:1.Four types of inclusions are found, which are liquid, gas, H2S-rich and polyphase inclusions with NaCl daughter minerals.2.Inclusions formed in different mineralization periods and stages yielded different homo-genization temperatures Th and salinities; the first silver mineralization stage with Th = 350-400℃ and =5-18 wt% equiv. NaCl, the Second stage with Th = 270-320℃ and Salinity = 8-14 wt% equiv. NaCl, and the last stage with Th = 180-230℃ and Salinity = 5-9 wt% equiv. NaCl; the first lead-zinc mineralization stage with Th = 220-280℃ and salinity = 4-8 wt% equiv. NaCl, and the last stage with Th = 130-190℃ and salinity = 2-6 wt% equiv. NaCl.3.The pressure of mineralization at least is about 200 bars.4.Ore-forming fluids are rich in Na, K, S, and possibly Cl.5.Evidence of boiling of the hydrothermal system has been found.According to the study of inclusions and other geological-geochemical evidence, we have come to the conclusion that the ore-forming fluids with moderate to low salinity and high concentration of Na, K, S, and possibly Cl, which came from the mixture of meteoric water and magmatic water, brought ore metals (e.g. Ag) into the mineralization structure, resulting in the mesoepithermal deposit in a supergene environment.
出处
《地球化学》
CAS
CSCD
北大核心
1989年第2期139-148,共10页
Geochimica
