Abstract The Late Mesozoic Jinchanggouliang and Erdaogou lode gold deposits in the central segment of the northern North China Craton are mainly hosted in Late Archaean metamorphic rocks of the Jianping Formation and Jurassic volcanic-sedimentary rocks. These deposits are spatially and temporally associated with a series of I-type granitoid intrusions: i.e., the 128–136 Ma Duimiangou granodiorite complex with a massive margin and a porphyritic center at Jinchanggouliang, the 161.4 ± 1.1 Ma Loushang quartz diorite intrusion and numerous syenite porphyry dykes (160.9 ± 1.0 Ma) at Erdaogou, and the ~ 227–217 Ma Xitaizi monzogranite batholith. Compositions of primary magmatic biotite in these granitoid intrusions have been used to investigate the nature of granitoid magmas and the evolution of magmatic processes and to identify possible linkages between gold mineralization and granitoid magmatism. All primary magmatic biotite grains are Mg-rich in composition (XMg = Mg/(Mg + Fe) = 0.41–0.69). The Cl contents of biotite (0.09–0.42 wt%) in the Loushang quartz diorite and the Duimiangou massive granodiorite correlate negatively with XMg and are consistent with the “Mg-Cl avoidance” rule. The Cl contents of biotite (0.01–0.14 wt%) in the Duimiangou porphyritic granodiorite, syenite porphyry and Xitaizi monzogranite, on the other hand, remain relatively constant and may be affected by multiple variables such as Cl-rich fluids and subtle changes in temperature. Halogen fugacity of the parental magma calculated from biotite shows that the Duimiangou granodiorite complex at Jinchanggouliang and syenite porphyry dykes at Erdaogou have the log(fHF/fHCl) ranges of −0.71 to −0.27 and −2.16 to −1.08, respectively, and have similar log(fH2O)/(fHCl) values from 3.53 to 4.23. Oxygen fugacities (logfO2) calculated from biotite equilibria for the Duimiangou granodiorite complex and syenite porphyry dykes are −13.7 to −7.2, straddling on the nickel-nickel oxide and hematite-magnetite buffers. The Xitaizi monzogranite and the Loushang quartz diorite have lower log(fO2) values from −14.9 to −12.4, between the nickel-nickel oxide and hematite-magnetite buffers. The Duimiangou granodiorite complex and syenite porphyry dykes with high oxygen fugacities are similar to oxidized magmas associated with porphyry Cu-Mo-Au deposits. These results suggest that multiple episodes of I-type granitoid magmas in the study area were rich in Cl and high in oxygen fugacity, especially those associated with the Duimiangou granodiorite complex and syenite porphyry dykes. The I-type melts represented by the Duimiangou granodiorite complex and syenite porphyry dykes as well as their related Cl-rich, oxidizing fluids were likely efficient in dissolving, transporting and precipitating gold for the formation of the Jinchanggouliang and Erdaogou lode gold deposits.

中文翻译：

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华北克拉通晚中生代金厂沟梁-二道沟矿脉金矿床花岗岩类侵入体中原生岩浆黑云母：与金矿化的联系

摘要 华北克拉通北部中段晚中生代金厂沟梁和二道沟矿脉金矿床主要赋存于建平组晚太古代变质岩和侏罗纪火山-沉积岩中。这些矿床在空间和时间上与一系列I型花岗岩侵入体相关：即128-136马对面沟花岗闪长岩杂岩体，在金厂沟梁具有块状边缘和斑状中心，161.4±1.1马楼上石英闪长岩侵入体和大量正长岩二道沟的斑岩岩脉（160.9±1.0 Ma）和~227-217马西台子二长花岗岩基岩。这些花岗岩侵入体中原生岩浆黑云母的成分已被用于研究花岗岩岩浆的性质和岩浆过程的演化，并确定金矿化与花岗岩岩浆作用之间可能存在的联系。所有原生岩浆黑云母粒的成分都富含镁（XMg = Mg/(Mg + Fe) = 0.41–0.69）。娄商石英闪长岩和堆面沟块状花岗闪长岩中黑云母的Cl含量（0.09-0.42wt%）与XMg呈负相关，符合“Mg-Cl回避”规律。另一方面，对面沟斑状花岗闪长岩、正长斑岩和西台子二长花岗岩中黑云母的Cl含量(0.01-0.14 wt%)保持相对恒定，可能受富Cl流体和温度细微变化等多种变量的影响. 由黑云母计算的母岩浆卤素逸度表明，金厂沟梁对面沟花岗闪长岩杂岩和二道沟正长斑岩脉的log(fHF/fHCl)范围分别为-0.71～-0.27和-2.16～-1.08，具有相似的分布。 log(fH2O)/(fHCl) 值从 3.53 到 4.23。根据对面沟花岗闪长岩复合体和正长斑岩岩脉的黑云母平衡计算得出的氧逸度 (logfO2) 为 -13.7 至 -7.2，横跨镍-镍氧化物和赤铁矿-磁铁矿缓冲层。西台子二长花岗岩和娄上石英闪长岩的 log(fO2) 值较低，介于 -14.9 至 -12.4 之间，介于镍-镍氧化物和赤铁矿-磁铁矿缓冲层之间。对面沟花岗闪长岩杂岩体和高氧逸度的正长斑岩岩脉与斑岩铜钼金矿床伴生的氧化岩浆相似。这些结果表明，研究区多期I型花岗岩岩浆富含Cl，氧逸度高，尤其是与对面沟花岗闪长岩杂岩和正长斑岩岩脉伴生的岩浆。以对面沟花岗闪长岩杂岩和正长斑岩岩脉为代表的I型熔体及其相关的富氯氧化性流体可能有效溶解、输送和沉淀金厂沟梁和二道沟矿脉金矿床。尤其是与对面沟花岗闪长岩杂岩和正长斑岩岩脉伴生的岩脉。以对面沟花岗闪长岩杂岩体和正长斑岩岩脉为代表的I型熔体及其相关的富氯氧化性流体可能有效溶解、输送和沉淀金厂沟梁和二道沟矿脉金矿床。尤其是与堆面沟花岗闪长岩杂岩和正长斑岩岩脉有关的岩脉。以对面沟花岗闪长岩杂岩和正长斑岩岩脉为代表的I型熔体及其相关的富氯氧化性流体可能有效溶解、输送和沉淀金厂沟梁和二道沟矿脉金矿床。