Yantongqiaozi Au deposit, Meihekou Co., Tonghua, Jilin, Chinai

Regional Level Types
Yantongqiaozi Au deposit	Deposit
Meihekou Co.	County
Tonghua	Prefecture-level City
Jilin	Province
China	Country

The strata in the mining area include the Archean Yangjiadian Formation, Jurassic Houjiatun and Lazimen Formations, and Quaternary sediments. The Yangjiadian Formation, which is widely exposed in the mining area, comprises biotite–plagioclase gneiss and plagioclase amphibolite. The Houjiatun and Lazimen formations, situated in the southeastern part of the mining area, consist of siltstone- and shale-containing coal seams. An E–W-trending ductile shear zone crosses the area, extending 8 km in length and 150–500 m in width. A breccia pipe was formed at the intersection of the E–W-trending ductile shear zone and NE-trending faults, which has an elliptical surface exposure area of 1.5 km2.
Fifteen orebodies, hosted within the breccia pipe, have been delineated in the mining area, with well-substantiated gold reserves over 15 t with a gold grade of 9 g/t. The ore bodies exhibit lenticular and vein-like morphology, ranging from 50 to 590 m in length and 0.5 to 2.0 m in width.
Four stages (I–IV) were identified based on the mineral assemblage and paragenesis. Stage I mineralization primarily occurs in the breccia-type ores, forming pyrrhotite–pyrite–quartz cement. Stage II mineralization primarily occurs in stockwork-type ores, forming gold–pyrite–quartz stockworks or veinlets. This stage supports economically valuable gold production. Gold occurs predominantly as intergranular gold, followed by gold inclusions. Stage III mineralization is characterized by the presence of sphalerite, forming sphalerite–pyrite–quartz veins with widths of 1 to 3 cm. Stage IV mineralization is characterized by the presence of calcite. These veins mainly consist of calcite with minor quartz, chlorite, and pyrite, and are 0.5–2 cm in width.

Other Regions, Features and Areas containing this locality

References