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Geochemical Characteristics of the Ore ‐ forming Fluids of the Haigou Gold Deposit, Jilin
Author(s) -
Yinqing Li
Publication year - 1994
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/j.1755-6724.1994.mp7003004.x
Subject(s) - fluid inclusions , quartz , mineralization (soil science) , hydrothermal circulation , salinity , geology , mineralogy , meteoric water , supercritical fluid , geochemistry , analytical chemistry (journal) , chemistry , environmental chemistry , paleontology , oceanography , organic chemistry , seismology , soil science , soil water
The quartz in the Haigou gold deposit contains a great abundance of three‐phase CO 2 ‐NaCl‐H 2 O and two‐phase CO 2 ‐rich inclusions, which are associated with two‐phase NaCl‐H 2 O ones. The ore‐forming fluids, which were rich in CO 2 , are classified into two types with two different sources: the high‐salinity CO 2 ‐rich NaCl‐H 2 O fluid derived from magmatic hydrothermal solution, and the low‐salinity NaCl‐H 2 O fluid from ancient meteoric water. The optimum conditions for gold mineralization are 220‐300°C for the temperature, 4‐20 Mpa for the fluid static pressure, 1‐3 km for the mineralization depth, 2‐7 w (NaCl)/10 ‐2 for the fluid salinity, and 0.644 g/cm 3 for the total density. The fluid was in a critical or supercritical state at the initial stage of mineralization, and it boiled and was unmixed with CO 2 and NaCl‐H 2 O in the climax of mineralization, leading to the decomposition of Au‐chlorine complexes and the bulk precipitation of Au. The type, association, homogenization temperature and composition (CO 2 /H 2 O value etc.) are the microscopic criteria for distinguishing the auriferous quartz vein from the barren quartz vein.