Gold precipitation in hydrothermal systems is traditionally attributed to supersaturation of gold due to decreasing gold complex stability triggered by changes in physicochemical conditions of the ore fluid. However, ultrahigh-grade gold veins in orogenic (shear zone related) gold deposits can contain kilograms per tonne of gold or more, in marked contrast to the typically very low gold concentrations (tens of parts per billion) in fluid. The gold mineral assemblage is commonly restricted to native gold and/or Au-(Ag)-tellurides and occurs in micro-fractures of sheared quartz veins. Textural and compositional characterization of such assemblages, coupled with hydrothermal diamond anvil cell experiments and heating-freezing experiments, provides evidence for an alternative ultrahigh-grade gold enrichment mechanism via growth of polymetallic melt droplets induced by quartz fracturing. We propose that polymetallic melt droplets of Au-Ag-Te-Bi–rich composition form through adsorption-reduction of metal complexes on fractured quartz surfaces, where surface silanol groups and hydrogen serve as reductants. The melt droplets subsequently grow by catalyzing reduction of metal complexes and absorbing metals from fluids percolating in the fractured quartz network. The mobile and reactive polymetallic melt droplets can repeatedly react with the fluid on protracted quartz fracturing and efficiently continue to scavenge gold from multiple pulses of gold-undersaturated ore fluids.The precipitation of gold in hydrothermal ore deposits is generally attributed to the supersaturation of gold in aqueous or aqueous-carbonic fluids. However, it appears doubtful whether ore fluids can ever reach bulk saturation with respect to gold because of the relatively low concentration of dissolved gold species compared to gold solubilities (e.g., Simmons and Brown, 2006; Pokrovski et al., 2014; Guo et al., 2018). This suggests there may be precipitation mechanisms that are not controlled by bulk gold solubilities, especially for the formation of ultrahigh-grade gold veins. This is because gold supersaturation triggered by processes such as boiling and fluid mixing would be accompanied by the precipitation of quartz, calcite, and other common vein minerals, which strongly dilute gold grade. This contrasts with the observation that gold minerals, e.g., native gold or Au-(Ag)-tellurides, are frequently a major or dominant component in micro-fractures of ultrahigh-grade gold quartz veins that can contain kilograms or more of gold per tonne.Alternatively, gold far below bulk saturation can be fixed at mineral surfaces through adsorption-reduction reactions (e.g., Bancroft and Hyland, 1990; Widler and Seward, 2002). Highly efficient adsorption-reduction of gold complexes on fluid-mineral interfaces could be potentially achieved through the formation and growth of polymetallic melt droplets, which can catalyze the decomposition of metal complexes and subsequently absorb metals from solution into the polymetallic melt droplets (e.g., Trentler et al., 1995; Daeneke et al., 2018). Polymetallic melt droplets, dominated by low-melting-point chalcophile elements (i.e., Zn, Ga, As, Se, Ag, Cd, In, Sn, Sb, Te, Hg, Tl, Pb, and Bi; Frost et al., 2002) and Au, have been reported in hydrothermal gold deposits of different types (e.g., Ciobanu et al., 2006; Cook et al., 2009; Cockerton and Tomkins, 2012; Hastie et al., 2020; Jian et al., 2021, 2022). Moreover, the precipitation of polymetallic melt droplets from hydrothermal fluids through adsorption-reduction mechanisms on pyrrhotite has been experimentally proven (Tooth et al., 2011).None of these previous studies has, however, addressed the role of quartz in polymetallic droplet formation and gold enrichment, even though quartz commonly is the dominant mineral in gold ores. Furthermore, the ore fluids from which polymetallic melt droplets form have never been systematically investigated due to the scarcity of coexisting fluid inclusions suitable for characterization and analysis. Accordingly, empirical evidence for the exact temperatures and other physicochemical conditions of polymetallic droplet formation is largely lacking.Using a combination of scanning electron microscope (SEM) imaging and energy-dispersive X-ray spectrometry (EDS), heating-freezing experiments, and hydrothermal diamond anvil cell experiments, we present evidence for entrapment of polymetallic melt droplets in quartz, constrain the conditions of melt formation, and propose a model of ultrahigh-grade gold enrichment through polymetallic droplet growth induced by quartz fracturing and generation of hydrogen and silanol groups during earthquake faulting.The investigated ultrahigh-grade gold ore samples (>1000 g/t Au) were collected from the S16 gold-bearing quartz vein (34°24′N, 110°35′E), Xiaoqinling gold district, central China (Jian et al., 2015, 2021). The polymetallic melt droplets studied appear as polycrystalline inclusions in quartz. They coexist with low-salinity H2O-CO2 fluid inclusions (5.3–9.7 wt% NaCl equivalent, Th (total homogenization temperature) 293–400 °C; Tables S1–S2 in the Supplemental Material1) along healed fractures in quartz and in some cases were trapped within fluid inclusions (Fig. 1). The polymetallic inclusions invariably consist of multiple mineral phases, including petzite (AuAg3Te2), calaverite (AuTe2), native gold, tellurobismuthite (Bi2Te3), rucklidgeite (PbBi2Te4), altaite (PbTe), and chalcopyrite, with minor galena, bornite, hessite (Ag2Te), buckhornite (AuPb2BiTe2S3), and volynskite (AgBiTe2) (Fig. 2). Two hundred and seventy-five individual polymetallic inclusions from 10 assemblages were investigated by SEM-EDS, indicating that they are dominated by Au, Ag, Te, and Bi, with minor Pb, Cu, Fe, and S. The 10 inclusion assemblages give the following average bulk chemical composition: 31.0 ± 3.1 wt% Au, 18.3 ± 2.8 wt% Ag, 40.2 ± 2.7 wt% Te, 6.2 ± 2.1 wt% Bi, 3.6 ± 2.6 wt% Pb, 0.5 ± 0.3 wt% Cu, 0.1 ± 0.2 wt% Fe, and 0.2 ± 0.2 wt% S (Table S3). Backscattered electron images, photomicrographs, schematic drawings, and calculated compositions of the 275 polymetallic inclusions from the 10 assemblages can be found in Figure S1 and Table S4 (see footnote 1).On heating by a Linkam THMSG600 heating-freezing microscope stage, the polymetallic inclusions, consisting mainly of Au, Ag, Te, and Bi, started melting at phase boundaries or triple point junctions at temperatures as low as 180 °C (Fig. 3; Fig. S2), far lower than the Au-Ag-Te eutectic temperature (at 304 °C; Cabri, 1965) and the Bi-Te-Au eutectic temperature (235 °C; Prince et al., 1990). The low initial melting temperature of minerals within the inclusions is due to the co-presence of multiple elements (i.e., Au, Ag, Te, Bi, Pb, Cu, Fe, and S) and the chemical communication between different minerals at grain boundaries, because addition of multiple components to a melt system generally lowers the eutectic of that system (e.g., Frost et al., 2002).Complete melting of the polymetallic inclusions in air or in an inert atmosphere was not observed at temperatures as high as 450 °C in the Linkam heating-freezing cell. Nevertheless, complete melting of the inclusions was observed in a hydrothermal diamond anvil cell between 360 and 396 °C (Fig. 4; Fig. S3), as shown by the transformation of the melt inclusions into spherical droplets. These temperatures overlap with the total homogenization temperatures of the coexisting fluid inclusions between 293 and 400 °C (Table S2), suggesting that the now-crystalline polymetallic inclusions were trapped as melt droplets.The internal textures of the polymetallic inclusions also indicate that they were trapped as liquid droplets. The polymetallic inclusions invariably contain suites of multiple mineral phases that extend down to the nanoscale and display a consistent crystallization sequence (Figs. 1 and 2; Fig. S1), from early to late: chalcopyrite, tellurobismuthite–rucklidgeite–native gold, calaverite, altaite, and petzite. Chalcopyrite was the earliest phase to crystallize, growing from inclusion walls with intergranular spaces filled by later phases. Native gold, tellurobismuthite, and rucklidgeite crystallizes after chalcopyrite and before other tellurides. The three minerals display undisrupted crystal faces against other tellurides. Petzite always occurs as anhedral grains and displays low grain-boundary angles against adjoining phases, suggesting it was the last phase to crystallize and thus fills any remaining space in the inclusions.Quartz is commonly regarded as a chemically inert mineral. However, surface defect sites on quartz are very reactive, and these surface defects possess a high capacity to adsorb and reduce metals (Heinhorst and Lehmann, 1994; Mukherjee et al., 2002; Mercadal et al., 2021). When silicate minerals are mechano-chemically activated, the atomic bonds of SiO2 are broken. Reactive sites including ≡Si• and ≡SiO• radicals and ≡Si+ and ≡SiO− ions are created. These species can recombine with each other to form siloxane bonds (Si─O─Si) or react with H2O molecules to form silanol groups (≡Si─OH) and hydrogen radicals (Kita et al., 1982):The hydrogen radicals then recombine to form H2 molecules. This process has been experimentally proven by crushing quartz under water-saturated conditions (Kita et al., 1982). High-velocity friction experiments on various rock types, simulating earthquakes, have reproduced the generation of hydrogen as a linear function of frictional work, i.e., H2 generation increases with earthquake magnitude following a power-law relationship (Hirose et al., 2011, 2012). Frictional work at elevated temperature to >~400 °C leads to the formation of very fine-grained reactive materials at the nanometer scale; free radicals on the fresh surfaces of the fine-grained particles react with H2O, leading to the generation of H2 (Hirose et al., 2011). Strong H2 enrichments have been reported in pseudotachylites formed by fracturing on fault planes (McMahon et al., 2016) and in active earthquake zones such as the San Andreas fault (California, USA; Wiersberg and Erzinger, 2008). Accordingly, we propose that Au and, by extension, also Ag, Bi, and Te metal complexes can be reduced by silanol groups (Mukherjee et al., 2002; Hofmeister et al., 2002) via reactions such as:or by H2 molecules (Merga et al., 2010; Mohammadnejad et al., 2013) via reactions such as:Once metal atoms are fixed onto the quartz surface, the dispersed atoms tend to agglomerate into larger clusters via Ostwald ripening. Importantly, in our case of a Au-Ag-Te-Bi–rich assemblage at 300–400 °C, the assembled atom clusters do not form critical nuclei that subsequently grow out into solids. Instead, these clusters grow as liquid droplets because their melting temperatures are lower than the fluid temperature.Polymetallic melt droplets, once formed, can catalyze the decomposition of metal complexes at the liquid metal-solution interface and subsequently absorb metals from solution (e.g., Trentler et al., 1995; Daeneke et al., 2018; Jian et al., 2021). Given that formation and growth of polymetallic melts are essentially adsorption-reduction reactions that do not require fluid saturation with respect to the constituent metals (e.g., Widler and Seward, 2002), this multistage process provides a mechanism by which solution components far below bulk saturation can be efficiently scavenged. For instance, the partition coefficient for Au between an aqueous fluid and bismuth melts is of the order of 107 for conditions typical of orogenic gold deposits (300 °C, pH 5; Tooth et al., 2008).Regarding quartz, a high density of surface defects is essential for the adsorption-reduction of gold. For instance, silica with a high density of surface defects (i.e., mesoporous silica, laser-irradiated quartz surfaces) is commonly used to synthesize gold nanoparticles (Kan et al., 2003; Mercadal et al., 2021) through the adsorption-reduction of gold complexes from solution on silica surfaces. Quartz is also known for its preg-robbing behavior in gold processing (Mohammadnejad et al., 2014). Fine-grained quartz (0.1–2.5 μm) can adsorb 98% of dissolved gold from solution in hours through adsorption-reduction of gold from solution, and grinding of quartz can considerably increase its adsorption potential due to increased surface area and physical defects (Mohammadnejad et al., 2013, 2014). Therefore, intense fracturing of quartz, such as in large shear zones, now partially recorded by densely distributed secondary fluid inclusion planes (i.e., healed micro-fractures), creates permeability and a high density of surface defects and, thus, favorable conditions for the adsorption-reduction of gold and, by extension, also Ag, Te, and Bi. Gold has the highest electronegativity (2.54; Pauling, 1960) among all metals; therefore, positive gold ions should generally be more easily reduced than those of other metals. However, further studies are required to fully understand the mechanism leading to the selective enrichment of Au-Ag-Te-Bi in polymetallic melt droplets, such as studies on metal complex species and their redox potentials, investigation of properties of polymetallic metal droplets, and experiments to replicate the formation of polymetallic melt droplets through quartz fracturing under ore-forming conditions.Lastly, the low melting point of the Au-Ag-Te-Bi–rich melt suggests that polymetallic melts could remain molten or partially molten for a long time. Thus, given favorable conditions, relatively low volumes of polymetallic melts can continue to scavenge gold from multiple pulses of ore fluids that are commonly involved in the formation of large gold deposits (Jian et al., 2022, 2024). For instance, polymetallic melt droplets previously trapped in quartz could be released due to quartz fracturing and again be exposed to aqueous fluids.In summary, we propose a model of ultrahigh-grade gold enrichment through quartz fracturing, adsorption-reduction of metals on reactive mineral surfaces, and formation and growth of polymetallic melt droplets, which catalyze the decomposition of metal complexes and scavenge gold during protracted shearing and fluid migration. Gold particles themselves are also known to act as catalysts during the reduction of positive gold ions (Polte, 2015). Repeated fracturing of quartz could then possibly also trigger self-catalyzed growth of metallic gold without the mediation of polymetallic melt droplets.This research was jointly funded by the National Natural Science Foundation of China (419720932) and the Fundamental Research Funds for the Central Universities (China; 2652020026). Bin Shi is thanked for his assistance with the SEM analysis. Qiang Liu is thanked for his assistance with the hydrothermal diamond anvil cell experiments. Li Jiang, Yongqi Su, Jinfeng Li, and Jinyu Shi are thanked for drawing the illustrations. Constructive reviews by Andy Tomkins and Krister Sundblad considerably improved the paper and are greatly acknowledged.

中文翻译：

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通过石英破裂和多金属熔滴生长实现金的超富集


热液系统中的金沉淀传统上归因于金的过饱和，这是由于矿石流体的物理化学条件的变化引发金络合物稳定性降低。然而，造山带（与剪切带相关）金矿床中的超高品位金矿每吨可能含有公斤或更多黄金，这与流体中通常非常低的金浓度（十亿分之一）形成鲜明对比。金矿物组合通常仅限于天然金和/或金（银）碲化物，并出现在剪切石英脉的微裂缝中。这种组合的结构和成分表征，加上热液金刚石砧室实验和加热冷冻实验，为通过石英压裂诱导多金属熔滴生长的替代超高品位金富集机制提供了证据。我们提出，富含 Au-Ag-Te-Bi 成分的多金属熔滴是通过金属配合物在断裂石英表面上的吸附还原形成的，其中表面硅烷醇基团和氢充当还原剂。随后，熔滴通过催化金属络合物的还原并从渗入破裂石英网络的流体中吸收金属而生长。流动性和反应性的多金属熔体液滴可以在长时间的石英压裂过程中与流体反复反应，并有效地持续从金不饱和矿石流体的多次脉冲中清除金。热液矿床中金的沉淀通常归因于金在矿床中的过饱和度。水性或水性碳酸液体。 然而，矿液是否能够达到金的体积饱和似乎值得怀疑，因为与金的溶解度相比，溶解的金物质的浓度相对较低（例如，Simmons 和 Brown，2006 年；Pokrovski 等人，2014 年；Guo 等人） .，2018）。这表明可能存在不受大量金溶解度控制的沉淀机制，特别是对于超高品位金矿脉的形成。这是因为沸腾和流体混合等过程引发的金过饱和会伴随着石英、方解石和其他常见脉矿物的沉淀，从而强烈稀释金的品位。这与金矿物（例如天然金或金（银）碲化物）的观察结果形成鲜明对比，这些金矿物通常是超高品位金石英脉微裂缝中的主要或主要成分，每吨可能含有公斤或更多的金或者，远低于体积饱和度的金可以通过吸附还原反应固定在矿物表面（例如，Bancroft 和 Hyland，1990；Widler 和 Seward，2002）。通过多金属熔体液滴的形成和生长，可以实现金络合物在流体-矿物界面上的高效吸附还原，这可以催化金属络合物的分解，随后将溶液中的金属吸收到多金属熔体液滴中（例如，Trentler）等人，1995；Daeneke 等人，2018）。多金属熔滴，主要由低熔点亲铜元素（即 Zn、Ga、As、Se、Ag、Cd、In、Sn、Sb、Te、Hg、Tl、Pb 和 Bi；Frost 等人， 2002年）和金，已在不同类型的热液金矿中得到报道（例如，Ciobanu等人，2006年；Cook等人，2009年；Cockerton和Tomkins，2012年；Hastie等人，2012年）。, 2020;简等人，2021，2022）。此外，通过磁黄铁矿上的吸附还原机制从热液中沉淀多金属熔体液滴已被实验证明（Tooth等人，2011）。然而，这些先前的研究都没有解决石英在多金属液滴形成和形成中的作用。金富集，尽管石英通常是金矿石中的主要矿物。此外，由于缺乏适合表征和分析的共存流体包裹体，形成多金属熔滴的矿石流体从未被系统地研究过。因此，关于多金属液滴形成的确切温度和其他物理化学条件的经验证据在很大程度上缺乏。结合使用扫描电子显微镜 (SEM) 成像和能量色散 X 射线光谱 (EDS)、加热-冷冻实验和水热法通过金刚石砧池实验，我们提供了石英中多金属熔体液滴截留的证据，限制了熔体形成的条件，并提出了一种通过石英破裂诱导的多金属液滴生长以及氢和硅烷醇基团的产生来富集超高品位金的模型。所调查的超高品位金矿石样品（> 1000 g/t Au）采自中国中部小秦岭金矿区 S16 含金石英脉（34°24′N，110°35′E）（简等人，2015，2021）。研究的多金属熔体液滴在石英中表现为多晶夹杂物。它们与低盐度 H2O-CO2 流体包裹体共存 (5.3–9.7 wt% 氯化钠当量，Th（总均化温度）293–400 °C；补充材料1)中的表S1-S2沿着石英的愈合裂缝，在某些情况下被困在流体包裹体中（图1）。多金属包裹体总是由多种矿物相组成，包括钾铁矿（AuAg3Te2）、钙镁铁矿（AuTe2）、自然金、碲铋矿（Bi2Te3）、卢克利金矿（PbBi2Te4）、钠钛矿（PbTe）和黄铜矿，以及少量方铅矿、斑铜矿、铁锰矿（ Ag2Te)、鹿角石 (AuPb2BiTe2S3) 和伏伦石 (AgBiTe2)（图 2）。通过 SEM-EDS 对 10 个组合中的 275 个单独的多金属包裹体进行了研究，表明它们的成分主要是 Au、Ag、Te 和 Bi，还有少量的 Pb、Cu、Fe 和 S。这 10 个包裹体组合给出了平均整体化学成分如下： 31.0 ± 3.1 wt% Au、18.3 ± 2.8 wt% Ag、40.2 ± 2.7 wt% Te、6.2 ± 2.1 wt% Bi、3.6 ± 2.6 wt% Pb、0.5 ± 0.3 wt% Cu、0.1 ± 0.2 wt% Fe，和 0.2 ± 0.2 wt% S（表 S3）。 10 个组合中 275 种多金属夹杂物的背散射电子图像、显微照片、示意图和计算成分见图 S1 和表 S4（参见脚注 1）。通过 Linkam THMSG600 加热冷冻显微镜载物台加热，多金属夹杂物主要由 Au、Ag、Te 和 Bi 组成的夹杂物在低至 180 °C 的温度下在相界或三相点结处开始熔化（图 3；图 S2），远低于 Au-Ag-Te共晶温度（304 °C；Cabri，1965）和 Bi-Te-Au 共晶温度（235 °C；Prince 等人，1990）。包裹体内矿物的低初始熔化温度是由于多种元素的共存（即、Au、Ag、Te、Bi、Pb、Cu、Fe 和 S）以及晶界处不同矿物之间的化学通讯，因为向熔体系统中添加多种组分通常会降低该系统的共晶（例如，Frost 等） al., 2002)。在 Linkam 加热冷冻室中，在高达 450 °C 的温度下，没有观察到多金属夹杂物在空气或惰性气氛中完全熔化。尽管如此，在 360 至 396 °C 之间的热液金刚石砧室中观察到了包裹体的完全熔化（图 4；图 S3），如熔融包裹体转变为球形液滴所示。这些温度与 293 至 400 °C 之间的共存流体包裹体的总均质化温度重叠（表 S2），表明现在结晶的多金属包裹体被捕获为熔滴。多金属包裹体的内部结构也表明它们是被困为液滴。多金属包裹体总是包含多种矿物相，这些矿物相延伸至纳米尺度，并显示出一致的结晶序列（图 1 和图 2；图 S1），从早期到晚期：黄铜矿、碲铋矿 - 鲁克利金矿 - 天然金、钙铜矿、阿尔泰石和钾钛矿。黄铜矿是最早结晶的相，从夹杂物壁生长，晶间空间被后来的相填充。天然金、碲铋矿和卢克利金矿在黄铜矿之后和其他碲化物之前结晶。与其他碲化物相比，这三种矿物显示出未受破坏的晶面。 钙钛矿总是以反角晶粒的形式出现，并且与相邻相显示出较低的晶界角，这表明它是最后结晶的相，因此填充了包裹体中的任何剩余空间。石英通常被认为是化学惰性矿物。然而，石英上的表面缺陷位点非常活跃，并且这些表面缺陷具有很高的吸附和还原金属的能力（Heinhorst 和 Lehmann，1994；Mukherjee 等，2002；Mercadal 等，2021）。当硅酸盐矿物被机械化学活化时，SiO2 的原子键被破坏。产生包括 ≡Si• 和 ≡SiO• 自由基以及 ≡Si+ 和 ≡SiO− 离子在内的反应位点。这些物质可以彼此重新结合形成硅氧烷键（Si─O─Si）或与H2O分子反应形成硅烷醇基团（≡Si─OH）和氢自由基（Kita等人，1982）：然后氢自由基重新结合形成H2分子。这一过程已通过在水饱和条件下破碎石英得到实验证明（Kita 等人，1982）。对各种岩石类型进行的模拟地震的高速摩擦实验，将氢气的产生再现为摩擦功的线性函数，即氢气的产生量随着地震震级的增加而增加，遵循幂律关系（Hirose 等，2011，2012） ）。高温至 >~400 °C 时的摩擦功会导致纳米级非常细粒的反应材料的形成；细粒颗粒新鲜表面上的自由基与 H2O 发生反应，导致生成 H2 (Hirose et al., 2011)。据报道，在断层面断裂形成的假速岩中存在大量的 H2 富集（McMahon 等，2017）。，2016）以及圣安德烈亚斯断层等地震活跃区（美国加利福尼亚州；Wiersberg 和 Erzinger，2008）。因此，我们提出，Au 以及 Ag、Bi 和 Te 金属络合物可以通过以下反应被硅烷醇基团还原（Mukherjee 等人，2002 年；Hofmeister 等人，2002 年），或者通过 H2 分子还原（Merga 等人，2010；Mohammadnejad 等人，2013）通过以下反应：一旦金属原子固定在石英表面上，分散的原子往往会通过奥斯特瓦尔德熟化聚集成更大的簇。重要的是，在 300-400 °C 的富含 Au-Ag-Te-Bi 组合的情况下，组装的原子簇不会形成随后生长成固体的关键原子核。相反，这些团簇以液滴形式生长，因为它们的熔化温度低于流体温度。多金属熔体液滴一旦形成，可以在液态金属-溶液界面催化金属络合物的分解，随后从溶液中吸收金属（例如，Trentler）等人，1995；Daeneke 等人，2018；Jian 等人，2021）。鉴于多金属熔体的形成和生长本质上是吸附还原反应，不需要相对于组成金属的流体饱和（例如，Widler 和 Seward，2002），这种多阶段过程提供了一种机制，通过该机制溶液组分远低于体积饱和度可以被有效地清除。例如，对于造山金矿的典型条件（300 °C，pH 5；Tooth 等，2008），水性流体和铋熔体之间的金分配系数约为 107。对于石英，高密度表面缺陷的消除对于金的吸附还原至关重要。例如，具有高密度表面缺陷的二氧化硅（即、介孔二氧化硅、激光照射的石英表面）通常用于通过二氧化硅表面溶液中金络合物的吸附还原来合成金纳米粒子（Kan 等人，2003 年；Mercadal 等人，2021 年）。石英还因其在黄金加工中的预浸行为而闻名（Mohammadnejad 等，2014）。细粒石英（0.1–2.5 μm）可以通过吸附还原溶液中的金，在数小时内吸附溶液中 98% 的溶解金，并且由于表面积增加和物理缺陷，石英研磨可以显着提高其吸附潜力（Mohammadnejad等，2013，2014）。因此，石英的剧烈破裂，例如在大剪切带中，现在部分由密集分布的次生流体包裹体平面（即愈合的微裂缝）记录，产生了渗透性和高密度的表面缺陷，从而为石英的形成提供了有利的条件。金以及 Ag、Te 和 Bi 的吸附还原。黄金在所有金属中具有最高的电负性（2.54；Pauling，1960）；因此，金离子通常比其他金属更容易被还原。然而，需要进一步的研究来充分了解Au-Ag-Te-Bi在多金属熔体液滴中选择性富集的机制，例如金属配合物种类及其氧化还原电位的研究、多金属金属液滴性质的研究以及实验复制了在成矿条件下通过石英破裂形成多金属熔体液滴的过程。最后，富 Au-Ag-Te-Bi 熔体的低熔点表明多金属熔体可以长时间保持熔融或部分熔融状态。 。 因此，在有利的条件下，相对少量的多金属熔体可以继续从通常参与大型金矿床形成的多次矿液脉冲中清除金（Jian et al., 2022, 2024）。例如，先前被困在石英中的多金属熔体液滴可能会因石英破裂而释放出来，并再次暴露于含水流体中。综上所述，我们提出了一种通过石英破裂、金属在活性矿物上的吸附还原来富集超高品位金的模型。表面，以及多金属熔体液滴的形成和生长，在长时间的剪切和流体迁移过程中催化金属络合物的分解并清除金。众所周知，金颗粒本身在金离子还原过程中可充当催化剂（Polte，2015）。石英的反复破裂也可能在没有多金属熔滴介导的情况下引发金属金的自催化生长。该研究由国家自然科学基金（419720932）和中央高校基本科研业务费专项资金（419720932）联合资助。中国；2652020026）。感谢 Bin Shi 对 SEM 分析的帮助。感谢刘强对水热金刚石砧细胞实验的帮助。感谢姜丽、苏永琪、李金峰和施金玉绘制插图。安迪·汤姆金斯 (Andy Tomkins) 和克里斯特·桑德布拉德 (Krister Sundblad) 的建设性评论极大地改进了本文，并得到了高度认可。