The extensive presence of monzogranite at the major “509 Daobanxi Li deposit” is interpreted as closely related to the formation of pegmatite veins and anomalous enrichment in lithium (Li). The recent identification of abundant pegmatite veins hosted by large-scale granodiorite bodies offers a new perspective for exploring the genetic and evolutionary relationships of phases within the Dahongliutan pluton. A systematic comparison of granodiorite, monzogranite, and pegmatite provides a more comprehensive understanding of the petrogenetic evolution between composite granites and pegmatites in the region, as well as the behaviour of Li during various magmatic stages. Representative granodiorite and pegmatite samples were systematically sampled based on detailed geological field investigations. Zircon U-Pb geochronology constrains the age of both the composite granite and pegmatite to ca. 220–207 Ma, indicating temporal continuity between the two. Tracing the Sr-Nd isotopic ratios and Li isotope Rayleigh fractionation modelling indicate that Triassic turbiditic sedimentary rocks in the Bayankalashan Group probably provided a common source for both the composite granite and associated pegmatites. Integrated analysis of whole-rock geochemistry and electron microprobe data from feldspar and mica reveals that the granitic magma originated from the dehydration melting of a muscovite-rich source, whereas the pegmatitic melt was generated through fractional crystallisation of the granitic magma. Trace element variations in feldspars, along with Rayleigh fractionation modelling of Li, Rb, and Sr, suggest that the pegmatitic melt represent represented 70–80% of the fractional crystallisation, primarily driven by the differentiation of mica, plagioclase, and K-feldspar. Overall, the petrogenesis of the Dahongliutan pegmatite is subdivided into the stages of partial melting, ascent of granitic magma, and fractional crystallisation. The Li migration process also discussed in terms of source region characteristics and the evolution of the pegmatitic melt.

Recent exploration has demonstrated significant prospecting potential at the Huayagou Au deposit in Longnan mineral Field, Gansu Province, West Qinling Orogen, Central China. However, the nature and evolution of the auriferous fluids responsible for gold enrichment remain poorly constrained, hindering effective exploration targeting of high-grade ores. In this study, apatite and tourmaline closely associated with gold mineralization are investigated as mineralogical recorders of fluid composition and evolution. Integrated petrographic observations, TIMA phase mapping, cathodoluminescence imaging, electron probe microanalysis, and in situ trace element analyses were used to distinguish magmatic, metamorphic, and syn-ore hydrothermal generations of apatite and tourmaline, together with in situ Nd isotopic analyses of apatite and B isotopic analyses of tourmaline. Syn-ore hydrothermal apatite is characterized by homogeneous blue cathodoluminescence, fluorapatite compositions, strong LREE depletion, and εNd(t) values overlapping those of Triassic magmatic apatite, whereas Early-Devonian magmatic and metamorphic apatites display more distinct signatures. Tourmaline records a systematic evolution from early dravite to late schorl, accompanied by trace element enrichment and a shift toward heavier δ11B values. These mineralogical and isotopic features, together with published sulfur isotope constraints, indicate that gold mineralization at Huayagou was dominantly controlled by structurally focused metamorphic fluids, with localized Triassic magmatic–hydrothermal overprinting enhancing gold enrichment in high-grade ores. The Huayagou Au deposit is, therefore, best interpreted as an atypical orogenic gold system, highlighting enhanced exploration potential in structurally favorable zones at depth, particularly in the western part of the district where Triassic magmatism is inferred.

Porphyry deposits are major sources of molybdenum (Mo) and are closely linked to subduction- and collisionrelated tectonic settings. The transport and deposition of Mo from aqueous fluids are governed by changes in physicochemical conditions, which are recorded in the geochemistry of hydrothermal minerals. The Jinduicheng Mo deposit, located in the East Qinling Orogen of central China, is a giant Mo resource hosted in granitic and andesitic porphyries. Despite previous studies focus on its origin, the detailed mechanisms of hydrothermal mineralization, along with Mo transport and enrichment remain poorly understood. Hydrothermal biotite, which is commonly associated with Mo deposition in porphyry systems, provides valuable insights into ore-forming processes. This study investigates the major and trace element compositions of hydrothermal biotite from the Jinduicheng deposit to constrain the physicochemical conditions and reveal the evolution of the hydrothermal system. The studied biotite is classified as Mg-rich and crystallized at temperatures of approximately 229-331 degrees C, recording the thermal conditions of the main Mo precipitation stage. Its composition reveals consistently high oxygen fugacity, which favored the stability of soluble hexavalent Mo species in the hydrothermal fluids. The calculated intercept values of IV(F), IV(Cl), and IV(F/Cl) range from 1.06 to 1.55, -4.31 to -3.61, and 4.83-5.68, respectively. These yield high log(fH2O/fHCl) values of 3.71-4.37, low log(fH2O/fHF) values of 0.98-1.64, and log(fHF/fHCl) values of 0.49-1.64. Halogen fugacity calculations indicate that the hydrothermal fluids were exceptionally enriched in fluorine relative to chlorine, a characteristic that aligns with significant fluorite alteration observed in the deposit. This F-rich signature likely enhanced Mo extraction from the melt and its transport as molybdate complexes (e.g., KHMoO4 or NaHMoO4). The precipitation of molybdenite was primarily driven by the cooling of the hydrothermal fluids, which destabilized these complexes. Fluid mixing and pressure fluctuations likely played secondary roles in the formation of Mo-bearing veins. This study demonstrates that hydrothermal biotite geochemistry is a powerful tool for directly quantifying the oxidized, F-rich nature of ore-forming fluids, and for clarifying the dominant role of cooling in triggering Mo deposition in porphyry systems.

The Pangjiahe Au deposit is the largest gold deposit in the Fengxian district of the West Qinling Orogen (WQO), Central China. However, the timing of gold mineralisation and its relationship to the regional metallogenic evolution of the WQO remain poorly constrained. In this study, detailed geological investigations, TIMA mineralogical analysis, in situ Rb–Sr dating of hydrothermal sericite, and in situ Fe–S isotope analyses of auriferous pyrite were conducted to constrain the timing of mineralisation, the evolution of ore-forming components, and the regional metallogenic significance of the Pangjiahe Au deposit. Hydrothermal sericite intimately associated with gold mineralisation yields an in situ Rb–Sr isochron age of 207.6 ± 3.1 Ma, providing the first direct age constraint on gold mineralisation at Pangjiahe. This age is consistent with those reported for the nearby Huayagou Au deposit and several other major gold deposits in the West Qinling Orogen, supporting a regionally extensive Late Triassic gold mineralisation event. The Pangjiahe Au deposit shares closer geological, geochronological, and isotopic affinities with the Huayagou Au deposit and the major Au deposits of the Middle Qinling in Gansu than with the traditionally correlated Au deposits of the North Qinling. These results provide new constraints on the regional metallogenic relationship between the Fengtai Basin and the Middle Qinling metallogenic system, contributing to a better understanding of Late Triassic gold mineralisation in the West Qinling Orogen.

Physicochemical conditions play a key role in magmatic differentiation, fluid exsolution and migration, and the enrichment of ore-forming elements in porphyry deposits. Biotite is a critical indicator mineral that has been used to constrain physicochemical conditions and trace the hydrothermal evolution of mineralisation. The Caosiyao deposit, a super-large porphyry Mo deposit located at the northern margin of the North China Block, has been primarily studied in terms of its metallogenic age and genetic evolution. However, the physicochemical conditions during magmatic and hydrothermal evolution remain poorly understood. This study analysed major and trace elements of hydrothermal biotite from the mineralised granite porphyry to better constrain the physicochemical conditions, hydrothermal evolution, and Mo mineralisation at Caosiyao. Hydrothermal biotite geochemical data reveals crystallisation temperatures ranging from 174 to 462 degrees C, high oxygen fugacity, and elevated F fugacity (IV(F) = 0.87-1.33; IV(Cl) =-4.63 to-3.74; IV(F/Cl) = 4.83-5.77). During the formation of deposit, the mixing of late hydrothermal fluids with meteoric water promoted the generation and transport of stable Cl-and Mo6+ complexes under favorable physicochemical conditions, resulting in significant Mo enrichment. The formation of the Caosiyao Mo deposit can be divided into three main stages: (1) The mineralisation process initiated with the generation of high-K, high-fO2granitic magmas derived from lower crustal melting, triggered by an enriched mantle source. Magmatic differentiation concentrated Mo in the residual melt, whereas fluid exsolution facilitated the migration of Mo-rich fluids along fractures, accompanied by widespread K-alteration. (2) Subsequent fluid-rock interaction led to the decomposition of Mo complexes and the precipitation of ore minerals in structurally weak zones. (3) In the late stage, the mixing of hydrothermal fluids with meteoric water and the release of sulfide altered the physicochemical conditions of the hydrothermal system, further enhancing Mo deposition. This study provides new insights into the common mineralisation processes observed in similar Mo deposits worldwide and offers significant implications for prospecting.

The Neoproterozoic Jiangnan orogenic belt (JOB) is an important Au-bearing belt in South China, yet the timing of gold mineralization has long been poorly constrained due to the lack of suitable dating minerals. This study presents integrated geochronological and geochemical data from five representative deposits in the Jinshan goldfield-the large Jinshan and Huaqiao altered-rock type deposits, the newly discovered Shiwu and Zhangjiafan deposits, and the Hamashi quartz-vein type deposit-located in the same district as the world-class Dexing porphyry Cu-Mo-Au system. In situ LA-ICP-MS U-Pb dating of hydrothermal apatite and zircon, coupled with Hf isotopic and trace-element analyses, yields precise age constraints and genetic insights. Apatite from the Hamashi quartz-vein deposit records a mineralization age of ca. 173 Ma, while zircon from the Zhangjiafan granodiorite porphyry gives an emplacement age of 171 +/- 2 Ma. These ages are coeval with the giant Dexing porphyry Cu-Au-Mo and Yinshan Cu-Au-Pb-Zn-Ag deposits, indicating a Middle-Late Jurassic metallogenic episode. Apatite from Zhangjiafan exhibits LREE enrichment, HREE depletion, and negative Eu anomalies, consistent with an igneous origin. Furthermore, hydrothermal apatite closely associated with gold in altered-rock type mineralization yields Early Cretaceous ages of ca. 129 Ma (Jinshan), ca. 128 Ma (Shiwu), and ca. 116 Ma (Huaqiao), with a corresponding quartz-vein age of ca. 125 Ma at Jinshan. This study defines, for the first time, revealing two discrete mineralization episodes in the Jinshan goldfield: Middle-Late Jurassic (ca. 178-166 Ma) and Early Cretaceous (ca. 130-116 Ma). The Rare Earth Element (REE) patterns of apatite closely related to the two periods of mineralization show significant differences. Early Cretaceous apatite shows higher total REE, Mn, Sr/Y, and (Gd/Yb)N values, but lower (La/Yb)N and (La/Sm)N ratios compared to Jurassic apatite, providing a geochemical fingerprint to distinguish the two mineralization events. These findings demonstrate that gold mineralization in the district is genetically linked to igneous intrusions associated with Jurassic and Cretaceous magmatism. The new geochronological framework, together with existing data from other Au-Sb-W deposits in the belt, significantly contribute to the understanding of metallogenic evolution in the JOB and highlights the high exploration potential for multi-episodic gold systems.

The Luanchuan jade deposit in the East Qinling Orogen, central China provides crucial clues to the tectonic evolutionary processes of the southern margin of the North China Block (NCB). The jade is primarily composed of serpentine jade with subordinate associated nephrite/tremolite jade, where the former is distinctly in contact with metamorphosed gabbro. Significant debate remains, however, regarding the jade types' spatial and temporal distribution and genesis. In this study, we integrate petrography, X-ray powder diffraction, geochemistry, S-Sr isotopes, and zircon U-Pb geochronology to elucidate the mineralogy, mineralisation processes, and tectonic setting of major serpentine jade occurrences. Our findings indicate that the ore bodies primarily underwent serpentine alteration, characterised by the mineral assemblage serpentine (antigorite)-dolomite-calcite-diopside-chlorite-pyrite. Pyrite shows a narrow range of delta 34S value from 3.4 to 5.6 parts per thousand, coupled with a Co/Ni ratio varying between 1.83 and 12.6, indicative of a magmatic-hydrothermal origin. Whole-rock geochemistry of the jade samples is characterised by a strongly negative Eu anomaly, a slight Ce anomaly, enrichment in light rare earth elements (LREEs), flat heavy rare earth elements (HREEs) patterns, along with significant U and Th enrichments, but depletion in Rb, Ba, Nb, and other trace elements. These characteristics indicate a close genetic link between the serpentine jade and its host dolomitic marble. Geochemical characteristics (Th/U, delta U, and delta Ce ratios) indicate that the jade was formed in an oxidized environment, while the whole-rock Sr/Ba, Zr/Hf, and Nb/Ta ratios depict its formation in an alkaline formation environment. The 87Sr/86Sr values in the jade samples range from 0.706459 to 0.709109, typical of marine Sr components pointing to inheritance from metasedimentary components. Zircon U-Pb dating of the metagabbro yields a concordant age of 860 +/- 8 Ma (interpreted as the crystallisation age) revealing a significant mid-Neoproterozoic magmatic event. In contrast, U-Pb dating of metamorphic zircon (with Th/U ratios of 0.02-0.24) from the jade (serpentinised marble) yields an upper intercept age of 1924 +/- 14 Ma. The date is interpreted as corresponding to a Paleoproterozoic tectono-thermal event that triggered the regional metamorphism of marine carbonate rocks into dolomitic marble. Integrated geological investigations reveal that the Mg and Ca at the Luanchuan serpentine jade were primarily derived from dolomitic marble. While the sources of SiO2 and H2O were associated with both metamorphic fluids and mafic magmatism, further confirmed by the comparatively close ratios of Eu/Sm and Sm/Nd between the metagabbro and samples of the Luanchuan serpentine jade. Our study emphasizes that the serpentine jade deposit primarily formed through multiple tectonic episodes, during which basic magmatic-hydrothermal fluids interacted with metamorphic processes, and the emplacement age of ca. 860 Ma is considered to interpret the upper age limit for the formation of the Luanchuan serpentine jade.

The Au-Sb assemblage is a common characteristic in low-temperature mineralisation, yet scientific investigations into this association remain limited. The West Qinling Orogen in central China hosts more than 50 Au deposits, with the Ludousou Au deposit in its northwestern part being closely related to reduced intrusive rocks characterised by a low oxidation state. Previous studies have largely focused on the geochronology and evolution of magmatic-hydrothermal fluids involved in the formation of the deposit. However, the relationship between Sb and Au has not been thoroughly examined. The Ludousou Au deposit is notable for its abundant hydrothermal tourmaline, a mineral with stable geochemical properties that make it a valuable tool for tracing the evolution of ore-forming magmatic-hydrothermal fluids and associated changes in physicochemical conditions. This study presents detailed in-situ analyses of major and trace elements in tourmaline to better understand the evolution of hydrothermal fluids and the separation of Au closely associated with pyrite and Sb that occurs as stibnite during regional Au mineralisation in the orogen. Tourmaline geochemical data reveal that Al substitution in tourmaline is governed by the mechanisms of Fe3+Al-1 and [AlO][(Fe, Mg)(OH)]-1. Meanwhile, V contents in tourmaline decrease from 978 ppm in the core to 96 ppm at the rim, and Cr contents drop from 2,177 ppm to 64 ppm, indicating a decline in the oxygen fugacity of the ore-forming fluids. Additionally, the concurrent decrease in Na and Ca contents in tourmaline, along with an increase in X-site vacancies, indicates increasing fluid salinity. These data also indicate that the mineralising fluids evolved from an initial magmatic-hydrothermal stage characterised by moderate temperatures, high salinity, and low oxygen fugacity, to a later stage marked by lower temperatures, reduced salinity, and higher oxygen fugacity. Geochemical analyses of tourmaline associated with pyrite and stibnite indicate that the segregation and precipitation of Au and Sb were driven by changes in physicochemical conditions caused by the influx of meteoric water. Antimony (Sb) shows a stronger temperature-dependent solubility than Au, resulting in its mineralisation occurring at later stages and under lower temperature conditions. This pattern is also observed in nearby giant Au deposits such as Zaozigou, Yangshan, and Zhaishang, contributing to a broader understanding of Au mineralisation in the region. Furthermore, similar Au-Sb relationships have been documented in various types of Au-Sb deposits worldwide, highlighting key processes involved in the differentiation and mineralisation of Au and Sb.

Magmatic anhydrite has long been regarded as diagnostic of oxidised intermediate–felsic magmas in porphyry Cu deposits. Here we report the world’s first occurrence of mantle-derived magmatic anhydrite in ultramafic rocks. The age of the clinopyroxenite and hornblendite hosting the anhydrite in the Langmuri magmatic platinum group elements (PGEs) sulfide deposit is 409 ± 2 Ma, shortly younger than the Paleozoic Oxygenation Event (POE). The anhydrite coexists with igneous carbonate minerals and Ca-O-C-Fe-S isotopes indicate oxidation of the mantle source by recycled oxidised surface-derived carbonates due to the POE. After the POE, the more oxidised supra-subduction mantle is coupled with the emergence of magmatic sulfide deposits in the orogen during the Late Paleozoic (410–270 Ma) and a rapidly increased frequency of porphyry Cu deposits worldwide. Our results further suggest that high-Mg basaltic magma, typically considered to be the parent magma of magmatic sulfide deposits in orogen, can evolve into PGE-enriched porphyry Cu deposit systems. This requires sufficiently high oxygen fugacity in magma after POE to retain sulfur predominantly as sulfate and thereby suppress sulfide saturation after olivine differentiation. Our findings link atmospheric oxygenation to deep Earth redox evolution, recording secular changes in Earth's redox state that fundamentally controlled the evolution of strategic metal sulfide deposits.

Structural and paleogeographic controls on sediment-hosted Au deposits are investigated using the giant Zhaishang Au deposit in the west Qinling orogen as an example. Two distinct types of mineralization are identified. The first is fault-controlled mineralization within Devonian Fe-rich calcareous siltstone, deposited in a platform-edge environment. The second is stratabound-replacement mineralization within Permian carbonaceous mudstone. This mudstone, which contains up to 1.46% organic carbon, was deposited in a low-energy, deep-sea environment. Geophysical sections demonstrate that the two types of Au mineralization are bounded by a WNW-ESE-trending fault called F5, which extends to a depth of at least 1 km with secondary mineralized structures converging into it. New structural mapping reveals that deposit-scale, NW-SE-trending locked-up folds and thrust faults developed under north-northeast-south-southwest compression at ca. 279 to 275 Ma according to the sericite Ar-Ar dating. In situ U-Pb dating of Au-related apatite from mineralized veinlets indicates that the WNW-to E-trending reverse faulting, stratabound replacement, and Au mineralization took place at ca. 220 Ma. The fault-controlled Au in the Devonian beds comprises polymetallic sulfides associated with decarbonation with both native gold and invisible Au within pyrite. In contrast, the stratabound-replacement Au orebodies in the Permian beds comprise pyrite and arsenopyrite hosting invisible Au associated with quartz alteration. The contrasting mineralization styles can be attributed to variations in host rocks and their mechanical competency determined by distinct paleogeographic settings and different pathways for fluid-rock interaction.

Hydrothermal sulfide deposits (e.g., porphyry and skarn) associated with felsic magmatism are major sources of chalcophile metals, including copper (Cu), molybdenum (Mo), gold (Au), lead (Pb), zinc (Zn), silver (Ag), and tin (Sn). However, the source of sulfur and metals remains debated. We report a study of clinopyroxene-hosted sulfide inclusions in mafic enclaves from the Beidashan granitic pluton (Northeast China), associated with a giant Sn-Pb-Zn-Ag-Cu deposit. Evidence shows the following: (i) immiscibility among Cu- and Zn-rich sulfide liquid, a silicate liquid, and an aqueous fluid during mafic magma emplacement in the upper crust; (ii) metal enrichment in FeS [iron(II) sulfide]-dominated melt inclusions (∼2628 parts per million of Cu, ∼233 parts per million of Zn, ∼275 parts per million of Pb, and ∼2.0 parts per million of Sn), reflecting strong partitioning into sulfide melts; and (iii) oxidative dissolution of sulfides by exsolved fluids, enabling metal transfer to the overlying felsic magma. The study demonstrates that metals in felsic-hosted deposits are sourced from subjacent mafic magmas and that mafic-felsic interaction triggered sulfide liquid/aqueous fluid cosaturation, ensuring efficient fluid-mediated chalcophile metal dissolution and transfer.

Physical and chemical (physicochemical) conditions are crucial for the genesis of a mineralised porphyry. For instance, a hydrothermal system with high oxygen fugacity facilitates Mo migration and precipitation. Zircon, the most common mineral enriched in rare earth elements (REEs), is widely used to determine the oxygen fugacity, magma evolution and mineralisation potential of a porphyry body. The Nannihu is a giant Mo-W porphyry deposit in the Qinling Orogen of central China and consists of porphyritic monzogranite. Previous studies have primarily focused on the age and petrogenesis of the deposit, but the physicochemical conditions remain poorly understood. Additionally, the mineralisation potential of the porphyry has not been evaluated, hampering the discovery of concealed Mo-W ores. In this study, we present in situ trace element analysis of zircon from the Nannihu porphyry to decipher the physicochemical conditions, magma evolution and evaluate the mineralisation potential of the area. The REE contents of the zircons range from 357 to 4768 ppm, characterised by depleted light REEs (LREEs) and enriched heavy REEs (HREEs). Using the zircon-Ti-thermometer and Ce/Ce* ratio, the crystallisation temperature of the Nannihu porphyry is estimated to be similar to 651 degrees C-769 degrees C, with an oxygen fugacity ranging from -30 to -1.7. By contrast, the crystallisation temperatures of the Nannihu porphyry are similar to those of nearby Shibaogou, Huangbeiling and Shangfanggou plutons in the Luanchuan region; its oxygen fugacity is moderate compared to these plutons. The porphyry formed in an intraplate setting and is derived from the crust. The crust in the Nannihu region underwent double thickening during similar to 148-138 Ma, reaching a depth of similar to 60 km. The zircons in the porphyry represent early products of a magma rich in H2O with a high oxygen fugacity, potentially influenced by F-rich hydrothermal input, which indicates a high prospectivity for Mo-W mineralisation in the vicinity of the deposit.

Compositional diversity is a common feature of plutons and a frequent topic in earth science publications. The Zhongchuan Batholith, a composite body in the West Qinling Orogen of central China, provides an important example for understanding compositional variations and the genesis of different granitic phases. The batholith consists of three annular rings (medium-coarse grained porphyritic biotite granite, medium grained phenocrystbearing biotite granite, and medium-fine grained biotite granite) from the outer to inner rings. Biotite is the most common ferromagnesian mineral in diverse granitic phases of the batholith and can serve as key indicators for the geochemical characteristics of the granites and their compositional variations. In this study, we present major and trace element geochemistry of biotite to constrain the physico-chemical conditions and petrogenesis of the various granitic phases in the batholith. Microstructural and alteration studies of biotite from the different granitic phases reveal features consistent with magmatic biotite. The major elements of the biotites indicate crystallisation temperatures of approximately 778 degrees C, 755 degrees C, and 726 degrees C for the outer, intermediate, and inner rings, respectively. These temperatures correspond to pressures of similar to 210 MPa (7.5 km), 390 MPa (14 km), and 440 MPa (16 km). The observed changes in crystallisation temperatures and pressures are consistent with the evolution of multi-stage and differentiated magma. The oxygen fugacity of biotite varies from -16 to-12, indicating a high magma oxygen fugacity. Major and trace elements of biotite further attest that the batholith is classified as I-type granite, derived from crust-mantle mixing, with a greater contribution of mantle-derived materials in the outer ring. The compositional diversity of the batholith is attributed to high-degree magma mixing without fractional crystallisation during magma evolution.

The study of metallogeny includes origin, development, modification, and preservation of mineralisation. The understanding of temporal evolution, and post-mineralisation modification and preservation of mineralisation are vital for building metallogenic theory and mineral prospecting, but they remain poorly understood and controversial. The Zaozigou deposit is the largest Au deposit in the West Qinling Orogen of central China with a resource of 142 t Au, and offers an excellent opportunity for deciphering the post-mineralisation exhumation and preservation of Au deposit in orogens. Here, we present integrated results from zircon U-Pb (ZUPb), apatite U-Pb (AUPb), apatite fission-track (AFT) and apatite (U-Th-Sm)/He (AHe) dating, thermal history modelling, biotite thermobarometer, and pyrite thermoelectricity of the deposit. The aims of the study are to decipher the temporal history, and post-mineralisation tectonic evolution and exhumation, and to evaluate the degree of exhumation and preservation potential of the deposit. Integrating the newly determined ZUPb (ca. 242–238 and 218–201 Ma), AUPb (ca. 247–235 Ma), AFT (ca. 237–186 Ma), and AHe (ca. 131–52 Ma) ages with multiple geo-thermochronological dates published from the Zaozigou deposit, major magmatic and hydrothermal events are recognised during ca. 250–233 and 230–203 Ma, with two Au mineralisation being deposited at ca. 230 and 211 Ma. The Zaozigou area underwent rapid post-magma cooling during ca. 250–228 Ma, rapid hydrothermal cooling at ca. 219–211 Ma, and episodic post-Triassic cooling pulses. Thermal history modelling indicates rapid cooling at ca. 210–170 Ma, slow reheating at ca. 170–60 Ma, and enhanced cooling during ca. 60–35 and 20–9 Ma at the Zaozigou deposit. In conjunction with the Triassic to Cenozoic tectonic evolution of the West Qinling Orogen, the ca. 250–233 Ma magmatism, ca. 230 Ma Au mineralisation, and ca. 250–228 Ma rapid postmagma cooling are related to the northward subduction of the Mianlue Ocean (Paleo-Tethys Ocean). The ca. 211 Ma Au mineralisation and rapid hydrothermal cooling during ca. 210–170 Ma are correlated with the collision between the South Qinling Belt and South China Block during ca. 220–210 Ma and the post-collisional gravitational collapse during the Jurassic. Prolonged reheating during ca. 170–60 Ma is associated with the unconformable deposition of coeval sedimentary sequences. The ca. 60–35 and 20–9 Ma enhanced cooling relates to the India-Eurasia collision, the northward growth of Tibetan Plateau, and the intensive East Asian summer monsoon during the Cenozoic. ∼28

Understanding postmineralization exhumation and preservation is crucial to better decipher ore-forming processes and optimize mineral exploration strategies. The Dashui goldfield is an archetypal epithermal goldfield in the world-class West Qingling gold province of central China, with a total resource of >120 tonnes (t) grading 6 g/t. Early studies have focused on genetic type, ore-forming materials and fluids, and age of Au-bearing calcite generations and coeval mineralizing dikes of the goldfield. However, ore-forming age and genetic type remain debated. Additionally, postmineralization exhumation, modification, and preservation of the goldfield has not been investigated, hampering gold exploration. In this study, we conducted same-sample apatite U-Pb (AUPb), apatite fission-track (AFT), and apatite (U-Th)/He (AHe) thermochronology and thermal history modeling to determine the timing of ore formation and postmineralization modification of the Dashui goldfield, allowing us to better focus future exploration for gold in the West Qinling orogen. AUPb and AFT dates (ca. 239-212 Ma) in this study, combined with published multiple geo-thermochronometric data, indicate that the Dashui goldfield formed through multiple episodes of gold mineralization during ca. 211-189 Ma. This corresponds to regional Triassic-Early Jurassic (ca. 249-194 Ma) gold mineralization in the West Qinling orogen. AFT (ca. 239-225 Ma) and AHe (ca. 176-107 Ma) dates, along with thermal history modeling, reveal rapid cooling (>5 degrees C/m.y.) during ca. 237-205 Ma, prolonged reheating (0.05-0.14 degrees C/m.y.) from ca. 205 Ma to 70 Ma, and multiple episodes of accelerated cooling (0.26-0.67 degrees C/m.y.) after 70 Ma at Dashui. Furthermore, published geo-thermochronometric data at Dashui also indicate an Early Jurassic (ca. 189-183 Ma) rapid cooling (>30 degrees C/m.y.) phase. Combining these results with the Mesozoic-Cenozoic tectonic evolution of the Qinling orogen, we interpret that ca. 237-205 Ma rapid cooling corresponds to the subduction of the Mianlue Ocean and the collision between the South Qinling terrane and Yangtze block. Early Jurassic rapid cooling (ca. 189-183 Ma) is attributed to the postcollisional extensional collapse and exhumation of the Qinling orogen during the Early to Middle Jurassic. Protracted reheating at ca. 205-70 Ma reflects coeval sedimentary burial of the Qinling orogen. Multiple episodes of accelerated cooling during ca. 70-50 Ma and 37-24 Ma are associated with coeval rapid exhumation (>0.01 mm/yr) of the Qinling orogen, the India-Eurasia collision, and the northward growth and lateral expansion of the Tibetan Plateau. Prolonged sedimentary burial between ca. 205 Ma and 70 Ma and episodic peneplanation events of the orogen during ca. 100-50 Ma, 47-38 Ma, and 33-13 Ma contributed to the preservation of gold mineralization at Dashui. Consequently, the West Qinling orogen is highly prospective for gold resources. We also propose that post mineralization sedimentary burial enhances the preservation of primary gold deposits, whereas rapid exhumation transfers gold to secondary reservoirs through erosional redistribution.

The Huayagou gold deposit, situated at Longnan-Fengtai mineral field (LMF) within the Western Qinling Orogen (WQO) of central China, is a newly identified deposit, representative of major deposits within Gansu section that hold significant geological and economic value. Its geological similarities to major deposits in Fengtai district underscore its importance for advancing regional mining exploration and metallogenic studies. However, the lack of robust geochronological data and detailed geological characterization hampers our comprehensive understanding of the deposit's genesis and regional metallogenic significance. To address this, research was carried out, involving detailed geological and mineralogical examination of ore samples from the Huayagou and subsequently robust chronology. Two distinct stages of mineralisation have been identified based on mineral association. The U-Pb dating of hydrothermal apatite that is closely associated with mineralisation yielded a 207Pbcorrected age of 205 +/- 23 Ma (MSWD = 0.4) on Tera-Wasserburg concordia diagram, interpreted as the timing for primary mineralisation event. Microscopic and geochemical analyses confirmed the hydrothermal origin of apatite, which intergrows with arsenopyrite and gold, providing a reliable chronological framework for the deposit's formation. These findings align with the 230-210 Ma mineralisation period established for major deposits in the LMF, such as Pangjiahe, Baguamiao, and Shuangwang. The ca. 248 Ma and ca. 163 Ma ages obtained from in situ Rb-Sr of sericite correspond to two rapid regional cooling events, possibly caused by uplifting and related metamorphism. Integrating these results into the regional geological context, we classify the Huayagou deposit as an orogenic gold deposit. This deposit, like others in the LMF, supports the spatial zoning model correlating uplift rates and erosion intensities with the distribution of epizonal, mesozonal, and hypozonal orogenic deposits across the western, central, and eastern regions of the field, respectively. The Late Triassic period in the WQO, characterized by the transition from subduction to collision to post-collision extension of the Paleo-Tethys Ocean, was a key phase for tectonic-magmatic activity and large-scale, multi-stage ore formation. Our findings reinforce this metallogenic framework and suggest significant potential for further gold exploration in the region.

Porphyry deposits are critical global sources of Cu, Mo, and Au. However, the mechanisms of post-mineralisation modification, exhumation, and preservation across different tectonic regimes remain poorly understood. The Mujicun deposit, a rare intracontinental porphyry Cu-Mo deposit in the North China Block, formed during the Early Cretaceous lithospheric thinning induced by the Paleo-Pacific slab rollback. Early studies focused predominantly on its genesis, the lack of research on post-mineralisation evolution has hindered regional prospecting. This study employs multiple geo-thermochronology, including zircon-apatite U-Pb and (U-Th)/He dating, as well as apatite fission-track analysis, combined with associated thermal history modelling, to elucidate the deposit's temporal evolution, exhumation history, and preservation potential. Geochronological data indicate that dioritic magma emplacement and related Cu-Mo mineralisation at Mujicun occurred at ca. 146-141 Ma and ca. 145-138 Ma, respectively, coinciding with regional extension driven by Paleo-Pacific subduction. Integrated geo-thermochronological data and thermal history modelling reveal four tectono-thermal phases: (1) Late Cretaceous rapid cooling (ca. 110-95 Ma) and slow cooling during ca. 95-66 Ma, linked to lithospheric thinning of the eastern North China Block and the early uplift of the Taihang Mountains, triggered by Paleo-Pacific subduction and Okhotomorsk-Eurasia collision; (2) Late Cretaceous to Paleogene weak reheating (ca. 85-35 Ma), attributed to coeval sedimentary burial in the North Taihang Mountain and the nearby Bohai Basin; (3) Paleogene slow cooling (ca. 66-35 Ma), correlated with Pacific slab rollback and far-field effects from the India-Eurasia collision, inducing extensional uplift and exhumation of the Taihang Mountains; and (4) Neogene enhanced cooling (ca. 35-15 Ma), driven by Pacific subduction, India-Eurasia convergence, Tibetan Plateau extrusion, and the intensified East Asian monsoon, resulting in differential exhumation and planation of the Taihang Mountains. The Mujicun deposit shows exceptional preservation, as its total exhumation depth since similar to 110 Ma (similar to 3.56 km) closely aligns with its original ore-forming depth (similar to 3.2-3.9 km). This indicates minimal post-mineralisation exhumation and limited erosional modification. Whereas current exploration targets shallow mineralisation (<1.5 km), significantly deeper regional ore-forming depths (e.g., Dawan Mo deposit: 0.76-9.76 km) highlight the important potential for undiscovered Cu-Mo resources at depth within the North Taihang Mountain. (c) 2025 China University of Geosciences (Beijing) and Peking University. Published by Elsevier B.V. on behalf of China University of Geosciences (Beijing). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Significant breakthroughs have recently been made in the Huayagou-Jinchanggou area of the Western Qinling Orogen (WQO), with estimated Au reserves of 20 t. However, the genetic relationship between magmatism and mineralization, as well as the mechanisms responsible for ore enrichment, remain unresolved. The Jinchanggou Au deposit, characterized by super-rich ores and multiphase magmatism, provides a valuable opportunity to clarify these issues. In this study, we investigated mineralization-related diorite dykes through zircon LA-ICP-MS U-Pb dating, mineralogical geochemistry, EPMA analyses, and elemental mapping of bismuth minerals in auriferous quartz veins. The results show that the diorite dyke was emplaced at ca. 211.8 Ma and is characterized by moderately high oxygen fugacity and water content, consistent with magma mixing as indicated by the abundance of acicular apatite. Multiple episodes of such intrusions released magmatic-hydrothermal fluids that contributed to gold enrichment. The quartz-vein-type ores at Jinchanggou, particularly late-stage gently dipping veins, differ from the regionally common disseminated-type ores and display features of orogenic gold systems with a magmatic-hydrothermal overprint, comparable to deposits such as Val-d'Or (Canada) and Shuangqishan (China). Combined with geophysical and metallogenic data, these features suggest that mineralization is linked to Yanshanian metallogeny, a rare event in the WQO. This study provides new evidence for multi-pulsed magmatic contributions to mineralization and highlights the potential for deeper mafic dyke-related gold mineralization along the Baguamiao-Jiutiaogou anomaly belt.

The genesis of mafic magmatic enclaves (MMEs) remains a topic of scientific discussion, particularly regarding their relationship to the mineralising potential of granites. This research presents geochemical, isotopic, and geochronological analyses of MMEs from the Shibaogou pluton in the Luanchuan Mo cluster within the East Qinling Mo metallogenic belt of central China. Our findings indicate that the MMEs, primarily quartz diorite, formed at ca. 144 Ma. These MMEs represent mafic magma derived from the mantle, which was injected into the molten felsic magma and subsequently underwent hybridisation with the host granites. The Shibaogou pluton is characterised by high-K calc-alkaline I-type granites, which originated from the partial melting of basaltic lower crustal rocks followed by fractional crystallisation. In the Luanchuan ore cluster, the Late Mesozoic granitic plutons with a higher abundance of MMEs are associated with increased erosion and reduced input of Mo-bearing ore-forming materials. This observation indicates a decreased exploration potential for granitic intrusions in the region. The logfO2 values of the MMEs from the Shibaogou pluton range from-25.6 to-6.5, consistent with those of their host granites. However, these values are lower than those observed in the Mo mineralised granitic plutons of the northern Nannihu ore filed, indicating a lower mineralising potential for the Shibaogou pluton in the Luanchuan area. The formation of the Shibaogou MMEs is attributed to asthenospheric upwelling and the underplating of lithospheric mantle-derived magma, while the host granites formed through the partial melting of basaltic lower crust. Additionally, the formation of both the MMEs and their host granites reveals a Late Mesozoic tectonic transition from a syn-collisional compressional to a within-plate extensional setting. The limited exposure of mafic-dioritic rocks, including MMEs, in the Luanchuan area reflects the restricted nature of asthenospheric upwelling. This study underscores the importance of MMEs in evaluating the exploration and mineralising potential of granitic intrusions.