The Liaodong Peninsula is an important mineral province in northern China. Elucidating its lithospheric architecture and structural evolution is important for gold metallogenic research and exploration in the region. In this study, Hf-Nd isotope maps from magmatic rocks are constructed and compared to geological maps to correlate isotopic signatures with geological features. It is found that gold deposits of different age periods in Liaodong are located in areas with specific εHf(t) and εNd ranges (Triassic: from −8 to −4 and from −12 to −8, Jurassic: from −22 to −8 and from −14 to −8, Cretaceous: from −12 to −10 and from −22 to −20), respectively. This may reflect that when the Paleo-Pacific plate was subducted beneath the North China Craton, the magma was derived from the juvenile lower crust and the ancient lower crust, and formed the low-to-moderate hydrothermal Au-(Ag) and Pb-Zn deposits in the Triassic. In the Jurassic, continued subduction may have led to lithospheric thickening. Subsequently, the magma from the ancient lower crust upwelled and formed low-to-moderate hydrothermal Au deposits and porphyry Mo deposits. In the Cretaceous, crustal delamination may have taken place. The magma from the ancient lower crust upwelled and formed various low-to-moderate hydrothermal Au deposits.

In porphyry systems, the physicochemical properties of ore-related intrusions critically influence both metallogenic fertility and the resulting metal assemblages. Biotite is a widespread magmatic mineral capable of recording subtle changes in physicochemical parameters throughout the evolution of porphyry systems. Throughout the years, several biotite thermobarometers have been proposed; however, the most appropriate combination for application to porphyry systems remains uncertain. In the Julong Cu–polymetallic district, where magmatic biotite is pervasive in the ore-related intrusive suite, we integrate available temperature, pressure, and oxygen fugacity data to assess which combination of biotite-based thermobarometers best captures the physicochemical condition of the magma. Our results demonstrate that the structural formula recalculation method of Li et al. (2020), when combined with the thermometer of Li and Zhang (2022) and the barometer of Uchida et al. (2007), yields the most accurate reconstruction of magmatic conditions in porphyry systems. In the Julong district, this integrated approach reveals that the earliest granodiorite crystallized at depths of ~3.2–6.3 km, under strongly oxidizing conditions (~NNO+3 to HM) and in the presence of elevated volatile concentrations. A slightly younger monzogranite formed at ~4.4 km depth, recording lower oxygen fugacity conditions (~NNO+2 to NNO+4). Its elevated F concentration and lower oxygen fugacity suggest a genetic link to the fractional crystallization of magmatic phases, especially magnetite. On the other hand, the ore-related monzogranite porphyry (~NNO+3 to HM) shares the oxidized signature of the granodiorite and was emplaced at ~3.4 km depth. Its low log(f_H2O/f_HCl) value reflects elevated HCl activity, conducive to the efficient magmatic transport of Cu and Mo.

青山金铅矿床位于柴北缘滩间山矿集区内,是全球罕见的金-铅共/伴生的造山型矿床。矿体主要赋存于古元古代达肯大坂群片岩中,受到北西西向断裂控制,发育蚀变岩和石英脉两种矿石类型,矿石中硫化物较为发育,常见黄铁矿、褐铁矿、方铅矿、黄铜矿、闪锌矿等。黄铁矿作为该矿床的主要载金矿物,其地球化学特征可以指示金赋存状态,揭示成矿流体性质和矿床成因。为此,选取ZK2103和ZK3701钻孔中不同深度空间的矿石和围岩样品,分别进行成矿元素全岩测试和黄铁矿的电子探针分析工作。矿石和围岩稀土元素配分模式曲线都为右倾型,呈现明显的Eu负异常,未见Ce异常,说明成矿流体为变质流体且不含海水。矿石相对富集Au、Ag、Cu、Pb、Zn、As、Co、Bi、Sb、W、Ni、Sr、Cd、V元素,而Sn、Mo、Cr元素含量则相对偏低。矿石和围岩中黄铁矿的S/Fe值小于2.0,表现出亏S和富Fe的特征;黄铁矿的Au/Ag值均大于0.5,Co-Ni图解结果指示黄铁矿为热液成因。金主要以纳米粒子形式赋存,少量以固溶体形式存在。金在流体中以Au(HS)^-₂的形式运移,流体混合作用破坏了Au(HS)^-₂的稳定性,致使金的沉淀。高硫的成矿流体可以运移部分的铜、铅、锌。在金沉淀后,成矿流体温度和压力降低,致使铅开始沉淀。但由于该流体运移铅、锌的能力有限,青山金铅矿床铅矿体的规模较小。硫-铅同位素结果显示成矿物质来源于围岩,区域上金龙沟矿区和青龙沟矿区围岩中铅锌含量较低,所以未形成铅矿体。

The Wulong deposit is a large gold deposit in the Liaodong peninsula (North China Craton). Silicic and pyrite alterations are well-developed in the deposit and closely related to mineralization. The least altered and silicified microdiorite samples were selected for major and trace element analyses to reveal the elemental migration/enrichment. Pyrites of stage 1 (Py1) were selected for backscattered electron (BSE) imaging and LA-ICP-MS trace element analyses to reveal their possible metallogenic link. Mass balance calculation showed that Al₂O₃, CaO, Fe₂O₃, K₂O, SiO₂, Ag, As, Cu, and Pb were brought in, whereas MgO, Na₂O, FeO, Cr, Zn, and Ni were leached out during silicification. LA-ICP-MS trace element analyses show that Py1 has higher Au and Zn contents than Py2 and Py3, Py2 has higher Au and Cu contents than Py1 and Py3, and Py3 has higher Pb, Cu, and As contents than Py1 and Py2. During the process of silicification and pyritization, the depleted H⁺ concentration and HS⁻ concentration in the ore-forming fluids led to instability of the Au(HS)²⁻ complexes and led to gold precipitation. The depleted sulfur and the reduced temperature during the precipitated of bismuthinite also led to instability of the Au(HS)²⁻ complexes and gold precipitation.