The Zhulazhaga gold deposit in the northern margin of the North China Craton (NCC) is a large tonnage h
ydrothermal deposit with a reserve of about 50 t at about 4 g/t Au. The deposit is characterized b
y an epigenetic st
yle of mineralization in metasedimentar
y rocks dominated b
y slates, low-grade metamorphic clastic rocks and minor volcanic rocks. Gold mineralization is dominantl
y controlled b
y structures, manifested b
y stratabound orebodies located immediatel
y to the east and west of a major N–S-trending fault and associated extensional fractures and NE-trending fault zones. The mineralization is also preferentiall
y located in the fourth sub-member of first member of the Agulugou Formation. There are man
y auriferous quartz veins parallel to the bedding of the host rocks which contain the orebodies, and high-grade ore preferentiall
y occurs near to these quartz veins. The structures provided pathwa
ys for transportation of gold-bearing fluids within the formation that appears to form a particularl
y favorable host rock and depositional setting.
Hydrogen and oxygen isotope data indicate that ore-forming fluids were dominated by magmatic water mixed with minor meteoric water. Sulfur and lead isotope data indicate that some sulfur and lead came from the magmatic fluid. The metallogenic age (280 Ma) of this deposit and the crystallization age (280–290 Ma) of the granite porphyry in the district indicate a link between the Hercynian magmatism and gold mineralization. The Hercynian tectono-magmatism and associated hydrothermal activity remobilized gold and drove ore-forming fluids to the favorable depositional environment.
The northern margin of the NCC is prospective for gold mineralization hosted in metasedimentary rocks which may be one of the most important deposit types for future gold exploration in northern China.