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Here we present our workflow, numerical models and results of the spatial distribution of chalcopyrite mineralization under the different porosity and permeability conditions of the host rocks of the Shaxi deposit. During the numerical modeling research, we tried to coupling heat transfer, fluid flow, material migration, mineralization reaction, and their coupling with porosity and permeability of rock. The results show that the porosity and permeability of the host rocks play a significant role in the mineralization of porphyry-type systems. The chemical properties of the strata restrict significantly on mineralization intensity and spatial extent rather than affecting the depth of mineralization. This paper also indicates that the numerical modeling method employed in this study can be used to predict the mineralization depth and spatial location of deep concealed porphyry-type deposits, aiding research in deep-seated mineral exploration. [Display omitted] • The porosity and permeability of the host rocks play a significant role in the mineralization of Shaxi porphyry-type deposit. • The chemical properties of the strata restrict significantly on mineralization intensity and spatial extent rather than affecting the depth of mineralization. • The numerical modeling may be used to predict the mineralization depth and spatial location of deep concealed porphyry-type deposits. The Shaxi porphyry-type Cu-Au deposit is located in the northwestern outer margin of the Luzong volcanic basin, which is situated in the Middle-Lower Yangtze River Metallogenic Belt (MLYRMB), Eastern China. It is a large porphyry-type Cu-Au deposit with confirmed copper resources exceeding 1 Mt and gold resources exceeding 40 tons. Previous studies have extensively investigated the genesis, controlling structures, geochemical characteristics, fluid evolution, alteration zone, and ages of mineralization and host rocks in this deposit. However, research on the influence of the physical and chemical properties of the host rocks on the mineralizing processes has not been explored in detail. This study employs the finite element method to apply numerical modeling of multiple physical and chemical fields, interlinking heat transfer, fluid flow, material migration, mineralization reaction, and their coupling with porosity and permeability of rock, to investigation of the influence of different porosities, permeabilities, and chemical properties of the host rocks on the mineralizing processes in the Shaxi deposit. The results show that the porosity and permeability of the host rocks play a significant role in the mineralization of porphyry-type systems. The different porosity and permeability of the intrusions and strata control the depth, the mineralization intensity, the morphology of the ore bodies, and the spatial location of the mineralization center. The chemical properties of the strata significantly restrict the mineralization intensity and horizontal spatial rather than affecting the depth of mineralization. Furthermore, the formation of skarn-type deposits may require a longer period of time than that of porphyry-type deposits under the same mineralization conditions and ore grade. This paper also indicates that the numerical modeling method employed in this study can be used to predict the mineralization depth and spatial location of deep concealed porphyry-type deposits, aiding research in deep-seated mineral exploration. [ABSTRACT FROM AUTHOR]

Based on the study of typical sandstone-type uranium deposits in China, the paper summarizes the characteristics of sandstone-type uranium deposits. The metallogenic elements of sandstone-type uranium deposit can be summarized into 5 aspects, which are "Source", "Reservoir", "Barrier", "Migration" and "Accumulation". Based on the research of metallogenic elements, three types of sandstone uranium metallogenic models are established in this paper, including the surficial infiltration fluid metallogenic model (Fig. 1), deep hydrothermal metallogenic model (Fig. 2) and superimposed metallogenic model (Fig. 3). This paper provide a better under-standing of the sandstone-type uranium. Once applied to underground examples, these models may allow the prediction of uranium ore body distribution. [Display omitted] • Distribution of sandstone-type uranium deposits in the world and China. • The elements of sandstone-type uranium metallogenesis are recognized as: source, reservoir, barrier, migration, and accumulation. • The sandstone-type uranium deposits are categorized into three metallogenic models: surficial infiltration fluid metallogenic model, deep hydrothermal metallogenic model, and superimposed metallogenic model. With the rapid development of nuclear power, the world demand for uranium is increasing year by year. Sandstone-type uranium deposits, as the primary target for uranium exploration and mining, have attracted more and more experts and scholars to conduct in-depth research with respect to ore morphology, metallogenic mechanism, metallogenic characteristics, and metallogenic models. In China, a lot of large and ultra-large sandstone-type uranium deposits were initially discovered by learning from international researches. However, these researches could not support operations on the sandstone-type uranium deposits with complex metallogenesis, resulting in no significant uranium breakthroughs in China over the past ten years. It is urgent to understand the metallogenic characteristics and models of sandstone-type uranium deposits. As the most popular deposits in China, sandstone-type uranium deposits are poor in southern China and rich in northern China − 88 % of sandstone-type uranium resources are found in sedimentary basins in northern China, mainly in Jurassic and Cretaceous strata. Five elements of sandstone-type uranium metallogenesis are recognized, i.e., source, reservoir, barrier, migration, and accumulation. Analysis results show that the sandstone-type uranium deposits discovered in China are obviously source-controlled, and mostly distributed 50 km away from their sources. Uranium reservoirs are generally large braided river or large braided river delta deposits, and locally large meandering river and fan delta deposits. They appear evidently in zones, an oxidation zone, a transition zone, and a reduction zone, which are different in color, mineral composition, and element content. Usually, stable barriers are developed at the roofs and floors of uranium reservoirs, and they provide strong supports for the sustainable and steady progress of uranium metallogenesis. Fluids as the carrier for uranium migration can be divided into two types: surficial infiltration fluid and deep upwelling fluid. Uranium metallogenesis is mainly controlled by reductants and adsorbents. Moreover, changes in fluid pH and temperature can lead to changes in uranium solubility in the fluid, allowing uranium to precipitate and accumulate into ore. Uranium generally occurs in three states: uranium mineral, adsorbed uranium, and uraniferous mineral. Based on the style of fluid migration, the metallogenic models of uranium deposits are divided into three types: surficial infiltration fluid, deep hydrothermal metallogenic fluid, and superimposed metallogenic models. The surficial infiltration fluid metallogenic model have two types: phreatic infiltration-type and interlayer oxidation-type. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrothermal apatite U–Pb age (208.1 ± 6.5 Ma) is coeval with peripheral intrusions. • C–O–S–Pb isotopes indicate a magmatic source for the ore fluid and material. • The Qukuleke is classified as a sediment-hosted intrusion-related deposit. • Intrusion-related Au ore system is a valuable target for regional exploration. Genetic classification of sediment-hosted Au deposits is often disputed in many orogenic belts around the world. The marine sediment-hosted Qukuleke Au deposit (>5 t Au) is an example of this, which has been attributed to orogenic or intrusion-related type. This paper addresses its metallogeny through detailed geologic and petrographic studies, together with apatite U–Pb dating and C–O–S–Pb isotopes. The hydrothermal paragenesis at Qukuleke is divided into three stages (I to III): Stage I (pre-ore) sheeted quartz veins; Stage II (main ore) pervasive sericite ± carbonate ± apatite ± pyrite ± arsenopyrite alteration associated with quartz–calcite ± stibnite veins; Stage III (post-ore) barren calcite veins. LA-ICP–MS hydrothermal apatite U–Pb dating on Stage II disseminated Au ore yielded 208.1 ± 6.5 Ma, coeval with the Late Triassic post-collisional intrusions from the periphery of Qukuleke deposit. Carbon–oxygen isotopes of Au–Sb ore-related hydrothermal calcite show that the hydrothermal fluids were derived from the marine carbonate ore host with considerable magmatic input. Lead–sulfur isotopes of the Au–Sb ore-related are consistent with those of coeval intrusions around the deposit, but different from those of the local sedimentary strata. Our age and geochemical data suggest the presence of a magma source that supplied the hydrothermal fluids, sulfur and metals for the mineralization. Combining the low sulfide content and the Au–As–W–Sb–Mo assemblage characteristics, the Qukuleke is best classified as a sediment-hosted intrusion-related Au deposit. Considering also the discovery of the large coeval Qukukekedong Au deposit nearby, we propose that Late Triassic intrusion-related Au system is a high-potential exploration target in the western EKOB. [ABSTRACT FROM AUTHOR]

This paper studies the mineralization process and the ore-forming setting of the Kantian fluorite deposit in South China through the zircon U-Pb chronology, quartz Rb-Sr dating, whole rock geochemistry, H-O isotope and fluid inclusions. A mineralization model for the Kantian fluorite deposit is proposed as follows: The subduction of the Pacific plate during the late mid-Jurassic and late Jurassic led to the formation of several fault zones. As the subduction gradually decelerated and eventually ceased, continental extension and lithosphere thinning occurred, accompanied by upwelling of the asthenosphere. This asthenosphere upwelling facilitated melting of the lithospheric mantle, resulting in the ascent of magma into the lower crust. Consequently, the intrusion of magma into the lower crust caused substantial heat, triggering partial melting of the lower crust. The molten material then ascended along faults, generating a significant quantity of granites. During the Early Cretaceous period, the Yanshan cycle witnessed another notable phase of magmatic activity. The residual magmatic hydrothermal fluid from this period served as a source of heating, while the pre-existing fault structures provided favorable pathways and storage space. Atmospheric precipitation infiltrated into the depth along these faults, and the deep-seated residual magmatic hydrothermal fluid heated the infiltrated atmospheric water, inducing cyclic upwelling. The upward migration of hydrothermal fluid continuously extracted Ca and F elements from the granites. Ongoing interaction between the fluid and the surrounding rocks led to changes in pH, coupled with alterations in temperature and pressure, ultimately resulting in the precipitation of fluorite with associated alteration zones in the surrounding rocks. [Display omitted] • Ca and F element in the fluorite were derived through the surrounding rocks. • The ore-forming fluids belong to the NaCl-H 2 O system and exhibit characteristics of medium–low temperature, low salinity, and low density, and were derived from meteoric water. • The intrusion age of surrounding rock in Kantian fluorite deposit was 159.4 ± 2.2 Ma, and the ore-forming of fluorite was 135.6 ± 0.7 Ma. • The tectonic setting responsible for the diagenesis and mineralization processes is believed to be an intracontinental stretching environment associated with the subduction of the Pacific plate. The Yanshanian events have led to the development of South China as a unique granite province globally. Within South Jiangxi, numerous metallic and non-metallic deposits have a close association with Mesozoic granite formations. The Kantian fluorite deposit, a newly discovered non-metallic deposit in southern Jiangxi Province, is one such deposit that is linked to Mesozoic granites. The orebody at the Kantian fluorite deposit is identified as occurring in veined structures within the silicification fracture zone of Mesozoic granites, with strict control exerted by fault systems. Fluorite ore can be classified into two categories based on the amount of quartz and fluorite. The first category is the fluorite quartz type, which has a higher amount of quartz than fluorite. The second category is quartz fluorite type, which has more fluorite than quartz. Among these two categories, the quartz fluorite type is precipitated during the primary mineralization stage. Through the analysis of fluid inclusions within the fluorite, it was determined that the homogenization temperature is relatively low, ranging from 133 to 236℃. The fluid inclusions also display low salinity (0.18–3.39 wt% NaCl eqv.) and low density (0.75–0.96 g/cm3). Laser Raman spectroscopy revealed that the primary components of the fluid inclusions are H 2 O, with minor C 3 H 6. Isotope analysis indicated δD VSMOW values of fluorite ranging from −61.9 ‰ to −54.8 ‰ (average −59.8 ‰), while δ18O VSMOW values varied from 1.3 ‰ to 3.1 ‰ (average 2.0 ‰). This study presents chronological, petrological and geochemical data that suggest several processes. The metallogenic age is 135.6 ± 0.7 Ma. The mineralizing fluids were identified to the NaCl-H 2 O system, with heated meteoric water identified as the primary source; The ore-forming materials originated from the granite, and water–rock interactions are proposed as the primary mechanism for fluorite precipitation. Based on a tectonic setting characterized by stretching, which is closely linked to the subduction of the Pacific plate, we proposed a model for the Kantian fluorite deposit. [ABSTRACT FROM AUTHOR]

[Display omitted] • The hydrothermal titanite associated with Au mineralization was formed at 130.8 ± 0.63 Ma. • The early Cretaceous Au mineralization overprinted the Triassic and late Jurassic Mo-Pb mineralization in Huangshui'an. • The gold precipitation mechanisms are sulfidation, collection-redissolution by LMCE melt, and changes in f Te 2 and f S 2. Huangshui'an deposit, situated in the Xiong'ershan area of Qinling orogenic belt (QOB) in China, is a globally rare carbonatite-type molybdenum polymetallic deposit that contains economic Mo, Au, Pb, and REE mineralization. The molybdenite Re-Os ages (Ca. 213.5–209.2 Ma) indicates that Huangshui'an Mo mineralization formed at Late Triassic. However, it is still unclear whether the Au mineralization is related to carbonatite dykes, and the formation age and genesis mechanism of Au mineralization remain poorly understood at Huangshui'an. This paper presents a comprehensive investigation of the Au mineralization events at the Huangshui'an deposit, including geology, mineralogy, and geochronology. The aim is to provide insights into its formation and mineralization processes and offer a broader understanding of regional Au metallogeny. Based on petrographic investigations, four stages are identified in the Au mineralization as follows: (I) quartz-K-feldspar stage; (II) quartz-pyrite-gold stage, including (IIA) pyrite-native gold sub-stage and (IIB) gold-tellurite-bismuthide sub-stage; (III) quartz-pyrite-polymetallic sulphide-oxide stage; and (IV) calcite-quartz-chlorite stage. The LA-ICP-MS titanite U-Pb dating yields a weighted mean age of 130.8 ± 0.63 Ma which determined that the Au mineralization at Huangshui'an was in the Early Cretaceous and was an independent mineralization event, which may be related to the lithosphere's destructive effect on the North China Craton (NCC). Combined with mineralography by automatic quantitative mineral analysis and testing system (TIMA), we consider that tellurium-bismuth minerals are closely associated with Au mineralization. The sulfur and tellurium fugacity of the ore-forming fluids in each stage were calculated using metal sulfide-oxides and tellurium-bismuth minerals. It was concluded that the precipitation of Au in the Huangshui'an deposit was mainly due to the combined effects of sulfidation, gold collection-redissolution by the low-melting point chalcophile elements (LMCE) melts, and the variation of sulfur fugacity and tellurium fugacity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fluid overpressure plays a key important role in the formation of skarn iron deposit. Skarn iron deposits are important resources for iron-rich ores and their genesis has been a topic of debate. The Nanminghe iron deposit is a typical skarn iron deposit in Wu'an, Hebei Province, China which provides a good example to investigate the metallogenic mechanism. In this paper, we present a detailed study of the geology, petrography, and geochemical characteristics of magnetite in the Nanminghe iron deposit. Two types of magnetite can be identified in the massive ores: Mag1 is euhedral with radial cracks developed in the margin. It is a low-Si magnetite, with SiO 2 content ranging from 0.07% to 0.92%, with an average value of 0.49%. The SiO 2 content of Mag2 is from 0.90% to 3.29%, and an average value of 2.03%. The Mag2 is associated with quartz, goethite, and apatite. Geochemical characteristics of Mag1, together with the ore textures suggest its crystallization from an iron magma. There are significant differences in the geochemical characteristics between Mag1 and Mag2. Mag2 is rich in Nb, Ta, high field strength elements, large ion lithophile elements and has higher silica content. The Nb/Ta of Mag2 is higher than that of the original mantle. These characteristics as well as La/Ta vs Th/La, Th/U vs Sm/Nd and Nb/Ta vs Nb features show that Mag2 is formed in the environment of supercritical fluids. The δ56Fe of Mag1 is 0.157‰-0.172‰, with an average value of 0.166‰, and the δ56Fe of Mag2 is 0.119‰-0.160‰, with an average value of 0.139‰. The Fe isotope of Mag2 is lighter than Mag1. There is a negative correlation between δ56Fe and SiO 2 of Mag1 and Mag2, suggesting that the lighter δ56Fe of Mag2 was caused by injection of Si-rich fluids. We propose a genetic model where we envisage that the iron-rich melt formed in the deep magma chamber by reaction of dioritic rocks and carbonates. Mag1 formed by cooling of the iron-rich magma, following which Si-rich supercritical fluid were injected into the deep chamber resulting in fluid overpressure. The iron-bearing melt-fluid migrated upward along the magmatic conduit, when Mag2 formed. Our study provides insights into the formation mechanism of skarn iron deposits. [ABSTRACT FROM AUTHOR]

[Display omitted] • The paleoclimatic conditions during deposition control the development of gray sandstone in the red beds. • The uranium mineralization in the red beds exhibits a certain correlation with the inorganic redox reactions involving iron. • Some dark mudstones in the red beds undergo a significant uranium pre-enrichment during deposition. • The climatic alternations lead to a weak reducing capacity in the red beds, with uranium mineralization occurring in the interior of the basin. The search for uranium deposits in the red beds is currently a hotspot in China's sandstone-type uranium exploration efforts. The typical occurrence of uranium deposits is within gray sandstone layers amidst the red beds, where the distribution of these gray sand bodies dictates the presence of uranium deposits. Hence, delving into the genesis of gray sandstone within the red beds proves beneficial for both uranium exploration and unraveling the ore-forming mechanisms. However, there is currently significant controversy surrounding the genesis of gray sandstone in the red beds. This paper focuses on the typical uranium deposit in the red beds—the HLJ-DL uranium deposit in the southwestern part of the Songliao Basin. It investigates the genesis of gray sandstone within uranium-bearing rock series and its relationship with uranium mineralization. The lithology of representative drill cores, including the red sandstone for comparative study, is methodically examined, along with their elemental geochemistry as well as carbon and oxygen isotope characteristics. The petrological characteristics suggest that both the gray and red sandstone share similar compositions of clastic particles, indicating minimal influence of the source rock on the sandstone color. The gray sandstone displays comparable TOC content (averaging around 0.05 %) and δ18O PDB values (averaging around −16 ‰) to the red sandstone. However, it exhibits relatively higher δ13C PDB values (averaging −0.26 ‰), whereas the average δ13C PDB value for the red beds is −1.61 ‰. The data indicate that the gray sandstone is less affected by hydrothermal or hydrocarbon fluids. Compared to the red sandstone, which has relatively higher Cu/Al values (averaging 1.09) and Fe3+/Fe2+ ratios (averaging 3.37), the gray sandstone exhibits low Cu/Al values (averaging 0.44) and a low Fe3+/Fe2+ ratio (averaging 0.36), suggesting its formation in a relatively reducing environment. The reducing conditions necessary for the formation of gray sandstone may stem from the climate becoming relatively warm and humid, irrespective of whether it originates from the original sedimentary environment or is induced by the reducing pore water discharged from dark mudstones. The chemical weathering index of fine-grained sediments indicates that, the gray sandstones were commonly configured in relatively humid-warm climate with fairly low dissolved oxygen content in the bottom water. Additionally, the deposition of the uranium-bearing rock series experienced alternating climatic changes, rather than consistently being in a humid-warm climate. This resulted in the sand bodies with low TOC content, insufficient reducing potential, and uranium mineralization primarily occurring in the interior of the basin. Organic matter has a relatively weak control over uranium mineralization, whereas uranium mineralization shows a certain correlation with iron reduction. The ore-forming fluid was uranium-rich oxygenated atmospheric water. Dark-colored mudstones, formed under humid-warm climatic condition, contain relatively high TOC contents (avg. 0.43 %) and exhibit a strong reducing capacity. The reducing pore water in dark-colored mudstones excreted into the adjacent sandstones under compaction during the early diagenesis, is able to serve as a vital reducing agent in later-stage uranium mineralization. Additionally, certain dark-colored mudstones with high uranium content (up to 944 ppm) undergo significant uranium pre-enrichment, providing a partial uranium source for uranium mineralization. [ABSTRACT FROM AUTHOR]

[Display omitted] • The study investigates cobalt concentrations in catchment sediments/soils across China, and reveal geochemical baselines of cobalt for the first time. • Correlations are established between cobalt concentrations and different rock types, notably basic and ultrabasic rocks, as well as cobalt concentrations and hydrothermal and laterite cobalt deposits. • The research assesses the effectiveness of low-density geochemical mapping in indicating cobalt mineralization, offering insights into its representativity on a continental scale. • Findings serve as foundational information for further geological studies, mineral exploration, and establishing baselines for cobalt resource exploration and pollution assessment on a continental scale. Cobalt is an essential component of Li-ion batteries. Due to the rapid growth of the electric automobile market in recent years, the global demand for cobalt has surged to an unprecedented level. It is crucial to understand the concentration and distribution of cobalt on a continental scale. The China Geochemical Baselines project, conducted from 2008 to 2012, provides valuable insights into this issue. Catchment sediments/soils were sampled at a density of 1 site per 3000 km2 across most of mainland China, and cobalt concentrations were determined using inductively coupled plasma mass spectrometry. Cobalt concentrations in top sediments/soils (0–25 cm) range from 0.02 μg/g to 77.56 μg/g, with a median value of 10.99 μg/g. In deep sediments/soils (100–150 cm) cobalt concentrations range from 0.91 μg/g to 80.79 μg/g, with a median value of 10.62 μg/g. Cobalt concentrations in top and deep sediments/soils exhibit remarkable similarity, consistently reflecting variations in lithology types of exposed crust. This suggests that the cobalt in catchment sediments/soils is primarily inherited from the rocks. Cobalt distribution patterns in China are consistent with rock types. The conterminous distribution patterns of high background concentrations falling in the Q75-Q85 range are mainly controlled by basic and ultra-basic rocks such as basalts and ophiolites. Sporadic anomalies beyond Q85 strongly correlate with hydrothermal and laterite cobalt deposits, but show weak correlation with magmatic cobalt deposits. This paper provides fundamental continental-scale information for further geological study and mineral exploration. [ABSTRACT FROM AUTHOR]

[Display omitted] • Phlogopite 40Ar–39Ar dating constrains the age of the Baijian deposit at ca. 128 Ma. • Magnetite and its equilibrated fluid acquire high δ18O values through fluid-wall rock interaction. • Interaction of magmatic fluids with evaporate-bearing carbonates may play a vital role in the district-wide Fe skarn mineralization. The Handan-Xingtai district, situated in the central part of the North China craton, is one of the most important concentrations of Fe skarns in China. Baijian is the largest Fe skarn deposit in this district with significant Fe reserves being newly identified. This deposit is spatially related with a monzodiorite stock intruding the Middle Ordovician evaporate-bearing marine carbonates, with Fe mineralization occurring in the contact zone or within carbonate wall rocks. This paper conducts a comprehensive investigation encompassing geological, mineralogical, geochronological, and stable isotope analyses of the Baijian deposit. The goal is to provide insights into its formation and mineralization processes and offer a broader understanding of regional Fe metallogeny. The skarn mineralogy in the Baijian deposit is predominantly characterized by Mg-rich minerals such as diopside, tremolite, serpentine, and phlogopite. Magnetite is the dominant metallic mineral, featuring low Ti contents (<0.11 wt%) and high Fe concentrations (>66.59 wt%), indicative of a hydrothermal origin. The majority of the magnetite trace element data are plotted in the skarn field on the Al + Mn versus Ti + V diagram. Pyrite, a notable component in ores, exhibits considerable variations in Co and Ni concentrations, with Co/Ni ratio generally higher than unity. Phlogopite 40Ar–39Ar dating constrains the formation of the Baijian Fe skarn deposit at ca. 128 Ma, aligning with zircon U-Pb ages (128.8 ± 0.9 Ma) of the associated monzodiorite. This temporal congruence suggests a genetic relationship between the magmatism and skarn mineralization. Combined with previous published geochronological data, this study identifies an increasing trend in Fe mineralization intensity within the Handan-Xingtai district, spanning from ca. 137 to 128 Ma. Geological and oxygen isotopic evidence advocates for a magmatic origin of the ore-forming fluids at the Baijian deposit. The δ18O values of these fluids experience elevation through interaction with carbonate wall rocks. The pronouncedly high δ34S values of pyrite (>16.1 ‰) in the Baijian magnetite ores underscore a substantial sulfur contribution from sulfate in evaporate beds. Drawing on geological, mineralogical, and isotopic evidence, the study suggests that the interaction between magmatic fluids and evaporate-bearing carbonate rocks plays an important role in magnetite precipitation at the Baijian deposit. This interaction serves to reduce fluid acidity and facilitate the oxidation of ferrous iron (Fe2+). The Fe skarn deposits in Handan-Xingtai district are mostly hosted in middle Ordovician evaporite-bearing carbonate strata with ore-related sulfides exhibiting strong 34S enrichment (δ34S > 10 ‰). The interaction of magmatic fluids with evaporate-bearing carbonates is likely a common process responsible for magnetite deposition in the Fe skarn deposits. [ABSTRACT FROM AUTHOR]

[Display omitted] • The bitumen in wall rocks and the Danzhai paleo-oil reservoir both originate from the Lower Cambrian source rock. • The paleo-oil reservoir and the ore sulfur both derive from seawater sulfate in the strata. The metallogenic metals are mainly sourced from the underlying strata and basement. • Bitumen Re-Os and sphalerite Rb-Sr isotopes yield isochron ages of 424±160 Ma and 398±4.7 Ma, respectively. • Hydrocarbons supply a large amount of reduced sulfur for mineralization through TSR reaction. The Niujiaotang MVT Pb-Zn ore field is located at the southwestern end of the West Hunan-East Guizhou (WHEG) metallogenic belt, which overlaps spatially with the Majiang paleo-oil reservoir. The Pb-Zn mineralization is closely associated with oil-gas accumulation processes. However, the genetic link between the paleo-oil reservoir and the Pb-Zn deposits remains unclear. In this paper, we present new findings of bitumen (paleo-oil reservoir) and its features in the deposits, and apply various isotopic geochemical methods and 2D seismic data to elucidate the source rock and coupling relationship of the paleo-oil reservoir and the Pb-Zn deposits. This study reveals that the ore has a simple mineral composition, mainly comprising sphalerite, pyrite, and dolomite. Solid bitumen occurs widely in the ore and the host dolostone, and coexists with minerals from the mineralization stage. Laser Raman spectroscopy shows that the bitumen in the wall rocks of the Chengong deposit and the Danzhai paleo-oil reservoir are both overmature, and their carbon isotope compositions (δ13C PDB = –29.17 ‰ – –31.20 ‰, average –30.10 ‰, n = 6) and initial 187Os/188Os ratio (1.08±0.19) suggest that they have the Lower Cambrian source rock similar to the Majiang paleo-oil reservoir. The δ34S value of pyrite in the bitumen from the wall rocks in the Chengong deposit ranges from +28.15 ‰ to +44.12 ‰ (average +33.28 ‰, n = 18), which is consistent with the sulfur isotope composition of the ore sulfide reported previously, indicating that they both derived from sulfate in the Middle-Upper Cambrian strata. Bitumen Re-Os and sphalerite Rb-Sr isotopic dating indicate that oil reservoir accumulation in the ore-hosting strata preceded Pb-Zn mineralization, occurring at 424±160 Ma (MSWD = 1.3) and 398±4.7 Ma (MSWD = 0.66), respectively. The initial 87Sr/86Sr ratio of sphalerite is 0.709983±0.000027, which, after comparison and in combination with previous studies, suggests that the metallogenic metals mainly originated from the underlying strata and basement. 2D seismic data show that the Zaolou fault (F 2) that controls the mineralization is a deep fault that extends to the basin basement, and acts as a migration pathway for hydrocarbon fluids and ore-forming materials. We propose that liquid hydrocarbons played a significant role in Pb-Zn mineralization, acting as reductants to reduce sulfate through the thermochemical sulfate reduction (TSR) reaction and provide abundant reduced sulfur (H2S/HS−) for Pb-Zn mineralization. Finally, we present a comprehensive model of hydrocarbon accumulation and mineralization in the Niujiaotang ore field. [ABSTRACT FROM AUTHOR]

[Display omitted] • The volcano-plutonic complex was mainly generated by the partial melting of lower crust. • Mantle delamination generated heterogeneous magma and thus a variety of deposits. • Intracontinental tectonic transformation controlled the porphyry emplacement. The Yao'an Pb–Ag–Au deposit is located far from the present-day margin of the Yangtze Craton, providing an excellent example for studying the genesis of porphyries and associated polymetallic mineralization in intracontinental transpression settings. In situ zircon U–Pb ages and Sr–Nd–Hf–O isotopic data of the Yao'an porphyries in the intracontinental zone, combined with research data published for the Machangqing and Beiya ore-bearing porphyries in the cratonic margin, were used in this paper. Four-phase felsic rocks (∼33 Ma) and later mafic rock (∼31 Ma) were recognized in the Yao'an district. Of these, the third-phase syenite porphyry had a genetic link with Pb–Ag–Au mineralization, which occurred within the second-phase volcanic rocks and Mesozoic strata. In addition, the Yao'an porphyry showed high initial 87Sr/86Sr ratios (0.7087–0.7094) and enriched Nd (ε Nd (t) = −10.53 to −12.60) isotopic composition, with a wide range of zircon Hf (ε Hf (t) = −8.39 to −13.2) and δ 18O values (6.28 ‰–9.20 ‰). These features suggest that the Yao'an porphyries were produced by partial melting of an ancient lower crust mixed with continental lithospheric-mantle-derived melt, which are differed from the magma source of the Beiya and Machangqing porphyries. Given the nature sources of the porphyries, we conclude that the spatial variation of metal associations changing from the Cu ± Au ± Mo system at the cratonic margin to the Pb–Ag–Au deposits in the intracontinental zone in the western Yangtze Craton was likely controlled by different magma sources. The delamination of an overthickened continental lithospheric mantle in an intracontinental transpression setting was a geodynamic trigger for porphyry magma generation, ascent, and emplacement. [ABSTRACT FROM AUTHOR]

[Display omitted] • Early Late Cretaceous Au mineralization in NE China. • Mantle contribution for Early Late Cretaceous Au mineralization. • Driven by the westward subduction of the Paleo-Pacific oceanic slab. The age and petrogenesis of volcanic–subvolcanic rocks associated with Au mineralization of the recently discovered Yidonglinchang Au deposit in the Lesser Xing'an Range provide insights into late Mesozoic Au metallogenesis in NE China. In this paper, we report zircon U–Pb chronological and Hf isotopic, whole–rock geochemical, and Sr–Nd isotopic data of the andesite porphyry and quartz diorite porphyry from the Yidonglinchang Au deposit. Zircon U–Pb dating shows that the andesite porphyry and quartz diorite porphyry associated with Au mineralization were formed at 101 and 99–97 Ma, respectively, suggestive of an early Late Cretaceous Au mineralization event in the Lesser Xing'an Range. Whole–rock geochemical data reveal that they have low SiO 2 contents (59.87–61.48 % and 55.91–63.22 %, respectively) and high Mg# values (41.5–55.4 and 43.2–61.3, respectively). In addition, these rocks are enriched in large–ion lithophile elements (e.g., K, Rb, and Ba) and depleted in high–field–strength elements (e.g., Nb, Ta, P, Ti, Zr, and Hf). The rocks have slightly negative to positive zircon ε Hf (t) values (−2.3 to 5.7) and negative whole–rock ε Nd (t) values (−3.3 to −2.9), indicating a metasomatized mantle source with some contamination by crustal materials. Combined with regional magmatic and metallogenic characteristics, we conclude that the Au mineralization at Yidonglinchang formed as a result of early Late Cretaceous magmatic–hydrothermal activities. Previously obtained data show that the orogenic Au deposits in the northern NE China formed mainly during the Early Cretaceous, earlier than the late Early Cretaceous to Late Cretaceous epithermal Au deposits in the eastern NE China. The formation of the late Mesozoic Au mineralization in the northern and eastern NE China was likely controlled by distinct tectonic settings. During the late Early to early Late Cretaceous, the rollback of Paleo–Pacific oceanic slab beneath eastern NE China generated an extensional setting that led to large–scale magmatism and associated Au mineralization. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Pianyanzi area in western Sichuan hosts a rare sellaite-bearing orogenic gold deposit. • Gold is mostly present as visible native gold formed in two stages. • Gold precipitation was forced by interaction between auriferous fluids and wall rocks. • Metasomatized mantle lithosphere served a potential source of ore fluids. The Pianyanzi gold deposit is situated at the western margin of the Yangtze Craton, and represents a rare sellaite-bearing orogenic gold deposit. This deposit belongs to the Dauduhe gold belt of southwestern China and remains poorly documented. In this paper we present first petrographic and in-situ geochemistrical and sulfur isotope data from pyrite as well as results of multielement mapping. The deposit is dominated by native gold (average gold fineness = 980.8) filling fractures in minerals (e.g., pyrite, quartz, sellaite and hematite) or also emplaced along the contact interface between mineral grains. Pyrite is the most abundant sulfide mineral of this deposit. We identified five generations of pyrite: Py1, Py2a, Py2b, Py3, and Py4. Gold occurs in sellaite- and hematite-bearing mineral assemblages formed simultaneous with the formation of Py2a&b and Py4, respectively. Py1 formed in the Au-poor ore stage, while Py3 formed during the late galena-dominated sulfide stage. All generations of pyrite exhibit low concentrations of gold with an average value of less than 2 ppm. Py2a&b possess distinctive textures and chemical zonation, with trace elements displaying greater variations compared to Py1, Py3 and Py4. The δ34S values vary from −0.52 ‰ to 7.08 ‰, which is consistent with those of orogenic deposits of the Daduhe gold belt. The deep metasomatized mantle lithosphere acted as a potential source of ore fluids. We conclude that the co-precipitation of native gold and sellaite was triggered by the interaction between auriferous fluids and dolomite. [ABSTRACT FROM AUTHOR]

[Display omitted] • The granodiorite porphyry in the Xiayi Sn deposit formed at 138 Ma, determined by zircon U-Pb dating. • Cassiterite U-Pb dating indicates a Sn mineralization age of 136 Ma in the Xiayi Sn deposit, which is contemporaneous with the granodiorite porphyry. • Hf isotope analysis of zircon suggests the involvement of mantle materials during the formation of the granodiorite porphyry. • Trace element compositions of cassiterite reveal distinct roles of Ti, W, Fe, V, and Sc in the cathodoluminescence (CL) response. • Our research provides valuable insights into the extension of the southeastern coastal metallogenic Sn belt into western Fujian Province. The Xiayi Sn deposit, located in the Sanming city, southeast China, is the largest Sn deposit in Fujian province. The mineralization mainly consists of cassiterite-bearing veinlets and stockworks, and it is spatially associated with the granodiorite porphyry. Despite its economic significance, few studies have been carried out, and the mineralization age remains unknown. In this paper, we present the first geochronological data on the cassiterite and the associated granodiorite porphyry, Hf isotope of the zircon, and trace element compositions of cassiterite from the Xiayi Sn deposit. These data give precise age of the Sn mineralization and constrain its relationship with the granitic intrusion. Zircon U-Pb dating of the ore-related granodiorite porphyry yielded the age of 138.3 ± 1.8 Ma, which agreed well with the cassiterite U-Pb age of 136.5 ± 1.4 Ma, documenting the genetic link between the Sn mineralization and granitic magmatism. Zircon εHf(t) ranged from −4.5 to −1.8 with a weighted mean of −3.4 and the Hf model ages (TDM2) vary from 1.31 to 1.47 Ga with a mean value of 1.40 Ga. These data indicate that the granodiorite porphyry originates from the partial melting of the crustal materials of Mesoproterozoic basement and show the addition of mantle-derived materials, similar to typical Sn mineralized granite in the southeastern coastal tin belt and Nanling tungsten-tin belt. Besides, cassiterite from Xiayi deposit show clear CL-bright and CL-dark sector zonation in the cathodoluminescence images. LA-ICP-MS trace element analyses of cassiterites indicate a high Ti and Fe but low Nb and Ta contents in both CL-bright and CL-dark sector zones, while the W content is significantly high in the CL-dark zone and low in the CL-bright zone. Cassiterite trace element compositions together with the mineralization pattern and alteration assemblages indicate that Xiayi is a porphyry tin deposit. These results provide proof of the extension of the southeastern coastal Sn metallogenic belt and offer potential breakthroughs in tin deposit exploration in southwestern Fujian Province. [ABSTRACT FROM AUTHOR]