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This paper presents an integrated study from fracture propagation modeling to gas flow modeling and a correlation analysis to explore the key controlling factors of intensive volume fracturing. The fracture propagation model takes into account the interaction between hydraulic fracture and natural fracture by means of the displacement discontinuity method (DDM) and the Picard iterative method. The shale gas flow considers multiple transport mechanisms, and the flow in the fracture network is handled by the embedded discrete fracture model (EDFM). A series of numerical simulations are conducted to analyze the effects of the cluster number, stage spacing, stress difference coefficient, and natural fracture distribution on the stimulated fracture area, fractal dimension, and cumulative gas production, and their correlation coefficients are obtained. The results show that the most influential factors to the stimulated fracture area are the stress difference ratio, stage spacing, and natural fracture density, while those to the cumulative gas production are the stress difference ratio, natural fracture density, and cluster number. This indicates that the stress condition dominates the gas production, and employing intensive volume fracturing (by properly increasing the cluster number) is beneficial for improving the final cumulative gas production. [ABSTRACT FROM AUTHOR]

The Wulonggou Gold Field is one of the giant gold fields in the East Kunlun Orogenic Belt, northwestern China. Previous studies mainly focused on elementary mineral isotopic studies, fluid inclusions, and geological features in the Wulonggou Gold Field. In this study, we report some research on the precise age and the specific ore-forming process of the WGF: the hydrothermal monazite U–Pb ages; the way of gold precipitation; the composition, evolution, and source of ore-forming fluids of the Wulonggou Gold Field. Finally, we demonstrate a link between two-stage hydrothermal events and sequential episodes of crust-derived magmas, with implications for gold metallogeny in the East Kunlun Orogenic Belt. There are four hydrothermal stages that are recognized: a quartz–pyrite stage (stage 1), a quartz–pyrite–arsenopyrite–chalcopyrite stage (stage 2), a quartz–galena–sphalerite–pyrite stage (stage 3) and a quartz–stibnite–carbonate stage (stage 4). The monazite U–Pb ages of the Huanglonggou and Hongqigou deposits in the Wulonggou Gold Field were 422.2 ± 2.4 Ma and 236.7 ± 3.7 Ma, respectively, which support the opinion of two epochs of mineralization. Stages 1 and 2 are the main gold mineralization stages, wherein Au and As have a close genetic relationship. The Hongqigou and Huanglonggou deposits seem to have been formed in different metallogenic events due to the contrast on the trace element compositions in pyrite. The sources of the ore-forming materials and fluids of the Hongqigou and Huanglonggou deposits show apparent characteristics of orogenic gold deposit, and the magmatic events during Paleozoic and Mesozoic have an important contribution to the formation of the gold deposits. The gold deposits in the Wulonggou Gold Field can be interpreted as an orogenic gold system related to two-epoch tectonic–magmatic events. [ABSTRACT FROM AUTHOR]

The Xiling gold deposit (>592 t @ 4.02 g/t) in the eastern Zhaoyuan-Laizhou gold belt of the Jiaodong Peninsula, is currently the largest gold deposit and deepest gold mine in China. This study presents microthermometric fluid inclusions data on quartz gangue, as well as trace element and S isotope data on pyrite from different mineralization stages and depths in the Xiling gold deposit to provide new insights into the spatio-temporal evolution of the ore-forming fluid that led to a giant Early Cretaceous gold deposit in the Jiaodong Peninsula. The δ34S values of pyrite range from 7.5 to 15.2 ‰, but vary temporally and spatially, reflecting a changes in physicochemical conditions as the ore-forming fluid migrated to different crustal levels over time, also suggesting Precambrian basement as the principal sulfur source. Trace element analyses of pyrite revealed that ore-forming metals were scavenged from the wall rock and then incorporated into the pyrite. Fluid inclusions data reveal that the ore-forming H 2 O-CO 2 -NaCl ± CH 4 fluid had a medium to high temperature (283–401 °C), medium-low salinity (1.91–8.00 wt% NaCl equivalent), analogous to most gold deposits in the Jiaodong Peninsula. Intensive interaction between the ore-forming fluid and wall rock changed the physicochemical conditions of fluid, leading to gold precipitation. The study supports the notion of the ore fluid of Jiaodong-type gold deposit having originated from a metasomatized lithospheric mantle. • Spatio-temporal fluid evolution is recorded by sulfur isotopes and trace element contents of pyrite. • The ore-forming fluids formed in a H 2 O-CO 2 -NaCl ± CH 4 hydrothermal system • The intensive fluid-rock interaction is the key for Xiling gold mineralization. • The Xiling deposit can be classified as the Jiaodong-type gold deposits. [ABSTRACT FROM AUTHOR]

Stress shadowing affects the simultaneous propagation of fractures from multiple perforation clusters. Employing uniform perforation parameters for all clusters cause the unbalanced growth of fractures, which arouses the demand of optimizing non-uniform perforation parameters. An optimization workflow combining a fracture propagation model and the particle swarm optimization method (PSO) is proposed for multi-cluster fracturing in this study. The fracture model considers the coupling of rock deformation and fluid flow along the wellbore and fractures, and it is solved by using the Newton iteration method. The optimization is performed by taking the variance of multiple fracture lengths as fitness value function in the frame of the PSO method. Numerical results show that using the same spacings and perforation parameters for all clusters is detrimental to the balanced growth of multiple fractures. The variance of fracture lengths drops greatly through optimization of cluster spacings and perforation number/diameter. Properly increasing the spacing and perforation number/diameter for the middle clusters promotes the balanced growth of multiple fractures. This study provides an efficient optimization workflow for multi-cluster fracturing treatment in horizontal wells. [ABSTRACT FROM AUTHOR]

Compositional changes in successively erupted felsic rocks can be used to infer physical changes in lower crustal conditions and to enhance the understanding of the tectonic regime. This study presents geochronological, geochemical and isotopic data for two I-type granitic plutons in the Sonid Left Banner of the Central Asian Orogenic Belt. Our new data, together with compiled I-type granitoid data, reveal the presence of magma compositional transition at ∼305 Ma in the Baolidao arc-accretion belt. The early stage granitoids (330–305 Ma) are medium-K calc-alkaline with higher Sr/Y ratios. The late stage granitoids (305–270 Ma) are high-K calc-alkaline with lower Sr/Y ratios. The two-stage granitoids have roughly similar predominately positive Sr−Nd−Hf isotope values, but with a decreasing trend from the early to late stages. Geochemical data indicate that the early stage granitoids were generated by dehydration melting of juvenile mafic crust at amphibole-dominated depths. In contrast, the late stage granitoids were produced by dehydration melting of a mixed lithology containing juvenile K-rich mafic lower crust and supracrustal materials at the plagioclase-stable crustal level. We propose that the compositional transition of these granitoids can be linked with different slab behaviors of the northward subducting Paleo-Asian oceanic plate, and also with the back-arc tectonic settings. [ABSTRACT FROM AUTHOR]

The Baishitouwa deposit is a medium-scale quartz–wolframite vein-type deposit in the southern Great Xing'an Range tungsten (W) belt. The W mineralization occurs mainly as veins and dissemination within the mica schist of the Mesoproterozoic Baiyunebo Group. The formation of the deposit can be divided into four stages. The wolframite yielded a lower intercept 206Pb/238U age of 221.0 ± 3.4 Ma (1σ, MSWD = 2.0), which records a late Triassic W mineralization event in the Baishitouwa deposit. In combination with previous geochronological data, we suggest that NE China may have an enormous potential for Triassic W mineralization and more attention should be given to the Triassic ore prospecting in the region. This work highlights that the chemical composition of wolframite is controlled by both the crystallochemical parameters and the composition of the primary ore-forming fluid. Trace-element compositions suggest that wolframite (I) was controlled by the substitution mechanism of 4A(Fe, Mn)2+ + 8BW6+ + B□ ↔ 3AM3+ + AN4+ + 7B(Nb, Ta)5+ + 2BN4+, whereas wolframite (II) was controlled by the substitution mechanism of A(Fe, Mn)2+ + A□ + 2BW6+ ↔ 2AM3+ + 2BN4+. Wolframite (I) contains higher concentrations of Nb, Ta, Sc, and heavy rare earth elements (HREEs), and lower Mn/(Mn + Fe) ratios than wolframite (II). Both wolframite (I) and (II) have similar trace elements and left-dipped REEN patterns, and analogical Nb/Ta ratios. They have similar Y/Ho ratios to Mesozoic highly fractionated W-mineralized granitoids in NE China. These data indicate that the W mineralization at Baishitouwa is genetically related to an underlying highly fractionated granite, and the compositional variation of fluids is likely driven by crystallization of wolframite during the processes of fluid evolution. A change of the ore-forming fluids from an oxidized to a relatively reduced state during the evolution occurred from stage 1 to 2. [ABSTRACT FROM AUTHOR]

The Aobaotu Pb–Zn deposit (470,700 t; 1.51% Pb, 2.30% Zn) in the southern Great Xing'an Range, northeastern China, is hosted by the Late Jurassic volcanic tuff and structurally controlled by a near‐east–west‐trending fault. Three stages of mineralization were identified, namely, stage I of quartz ± pyrite veins, stage II of quartz–polymetallic sulphide veins, and stage III of late quartz–calcite veins. The quartz and calcite that formed in the three stages were selected for fluid inclusion and C–H–O isotope analyses. The results show that the ore‐forming fluid of the deposit belongs to the H2O–CO2–NaCl system at a medium temperature (concentrated at 220–300°C) and in low salinity (0.7–12.1 wt% NaCl equiv). The δ13C values of the calcite and ankerite are in the range of −8.4 to −4.8‰, indicating that as a source of deep magma. The δDV‐SMOW and δ18OH2O values of quartz range from −108 to −88‰ and 4.55 to 5.85‰, respectively, indicating that the initial fluid of the Aobaotu deposit was a mixture of residual magmatic and meteoric water. Sulphur isotope analysis of the sulphide minerals, that is, sphalerite, galena, pyrite, and chalcopyrite, yield δ34S value in a range of 1.44–4.94‰, indicating that sulphur is mainly derived from magma. In addition, the Pb isotopic composition of the sulphides indicates that the ore‐forming material has a mixed crust–mantle source. Zircon U–Pb dating suggests that the formation of the Aobaotu deposit is genetically related to the granodiorite porphyry (130.3 ± 0.9 Ma). The combined geochronology and isotopic evidence suggest that the Aobaotu deposit is a magmatic‐hydrothermal vein‐type Pb–Zn deposit, opposite to a volcanic Pb–Zn deposit as suggested before. The Aobaotu deposit formed in an extensional tectonic setting caused by the rollback of the Palaeo‐Pacific Plate. [ABSTRACT FROM AUTHOR]

The Xindian deposit is a medium tonnage (>5 tonnes of Au) quartz vein‐type gold deposit located on the south‐central part of the Liaodong Peninsula, China. A total of 37 auriferous quartz veins are hosted within the Paleoproterozoic metamorphic rocks of the Gaixian Formation and Late Triassic porphyritic biotite granite. Mineral paragenesis indicates that gold mineralization took place in three stages: early milky quartz‐pyrite stage, main gray quartz‐polymetallic sulfide and gold stage, and late quartz‐calcite‐pyrite stage. Silicification and pyritization are spatially and temporally associated with the main mineralization stage. Zircon U–Pb dating from dikes that predate and postdate the mineralization constrain the timing of mineralization to the Early Cretaceous, between 127.2 and 120.9 Ma. High‐precision in‐situ S isotope analyses yielded δ34S values for pyrite, sphalerite and galena of 10.1–11.0‰, 10.3–10.5‰, and 8.6–8.8‰, respectively, indicating that S was derived from the multiple sources. In‐situ Pb isotope analyses resulted in 208Pb/204Pb, 207Pb/204Pb, and 206Pb/204Pb ratios of 38.207–38.634, 15.598–15.668, and 18.027–18.143, respectively, for pyrite and galena, suggesting Pb derivation from a mixture of Gaixian Formation metamorphic rocks and other potential sources. In‐situ LA‐ICP‐MS trace element mapping and spot analyses show that the inner core of the pyrite (Py‐ic) formed early and is generally enriched in Au, As, Co, Ni, Bi, and Te, the outer core of the pyrite (Py‐oc) contains less Co, Ni, As, and Au, but more Cu, Pb, and Zn, whereas the rim of the pyrite (Py‐r) is enriched in Ag, Sn, Sb, Cu, Pb, and Zn. Trace element signatures of pyrite reveal that the mineralizing fluid was initially of magmatic‐hydrothermal origin, and subsequently modified by intensive interaction with the wall rock (Gaixian Formation). Our results consistently demonstrate that the Xindian gold deposit is resulted from fluid–rock interaction between the Early Cretaceous magmatic‐hydrothermal fluids and Gaixian Formation metamorphic wall rocks that enriched the metal budget of the mineralizing fluid. Then the addition of meteoric water significantly changed the physical and chemical conditions of the mineralizing fluid, triggering gold precipitation in the Xindian deposit. The results of our study expand the Early Cretaceous gold metallogenic models in the Liaodong Peninsula, highlighting the importance of the Gaixian Formation for regional gold mineralization. [ABSTRACT FROM AUTHOR]

Аbstract: The formation of the West Kunlun Orogenic Belt, which is located at the northwest margin of the Greater Tibetan Plateau, is associated with the evolution of Proto- and Paleo-Tethys Oceans from the early-Paleozoic to the Triassic and characterized by intensive magmatism and extensive metallogenesis. This paper presents a detailed study of the LA-ICP-MS zircon U-Pb chronology, zircon Hf isotope geochemistry, and major and trace element composition of the Buziwannan granodiorite and monzogranite in the South Kunlun Terrane. The LA-ICP-MS zircon U-Pb dating shows that the two granites were emplaced in the late Triassic (231.8–226.8 Ma), and are high-K calc-alkaline I-type granodiorite and monzogranite in composition. Zircons from the Buziwannan granites have εHf(T) values ranging from –3.83 to 2.96, with corresponding two-stage Hf model ages (T(DM2)) of 1075–1505 Ma, suggesting the importance of juvenile material in the magma source. The Buziwannan granites show enrichments in LREEs, Rb, Th, U and Hf, and depletions in Sr, Nb, Ta and Eu. The contradiction between continental signature and mantle-like isotopes indicates the granites were generated by the partial melting of residual subducting slab with input of sediments. The ratios of Rb/Sr and (La/Yb)N increase from the granodiorite to monzogranite, while the Sr, Dy and Er values decrease. These data are attributed to fractional crystallization processes. Fractionation of plagioclase, hornblende and biotite produced the variations in major elements and Rb, Sr and Ba, and the distribution of REEs are mainly controlled by fractionation of hornblende and subordinately of zircon. Together with the regional geology, the data infer that the Buziwannan granites and corresponding mineralization formed in a transitional setting from syn-collision to post-collision during the Late Triassic. [ABSTRACT FROM AUTHOR]

The North China Craton contains voluminous gold deposits, which occur within the Northern Margin Gold Belt, the Southern Margin Gold Belt, and the Jiaodong Gold Province. However, relatively little is known of the gold deposits in the E–W-trending Northern Margin Gold Belt, which hosts 66 deposits with total reserves of >1000 tonnes. Based on a systematic summary of the geological features and ages of ore formation, three periods of gold mineralization can be distinguished: Permian–Triassic, Jurassic, and Early Cretaceous. Permian–Triassic gold mineralization occurs mainly as E–W-trending orogenic gold deposits with minor intrusion-related mineralization, formed in a syn- to post-collisional setting associated with closure of the Paleo-Asian Ocean. The Jurassic gold deposits occur in central and eastern parts of the Northern Margin Gold Belt as intrusion-related gold deposits that formed in a compressional setting associated with subduction of the Paleo-Pacific Plate. Early Cretaceous gold deposits in the eastern part of the Northern Margin Gold Belt are also intrusion-related, and formed in an extensional setting associated with rollback of the Paleo-Pacific Plate. [ABSTRACT FROM AUTHOR]

The Xinfang deposit is a large gold deposit (>20 t of Au) on the southern edge of the Liaodong Peninsula, China. A total of 37 gold‐bearing orebodies are identified along NS‐ and NW‐striking faults and are mainly hosted by the Archean and Neoproterozoic metamorphic rocks. Three stages of hydrothermal mineralization are distinguished, including Stage I of dominant quartz ± pyrite (Py1), Stage II of quartz‐polymetallic sulfide (Py2), and Stage III of quartz‐calcite ± pyrite (Py3). Gold primarily occurs at the Stage II in association with intensive silicification, pyritization, and sericitization. Here, we report on high‐precision in‐situ LA‐MC‐ICP‐MS analyses of S and Pb isotopic compositions of the sulfide minerals and LA‐ICP‐MS analyses of trace element signature of the pyrite from the Xinfang gold deposit. The δ34S values of the sulfides range from 1.3 to 5.3‰, which is consistent with a magmatic origin of S. The sulfides yield 208Pb/204Pb, 207Pb/204Pb, and 206Pb/204Pb ratios of 37.497–37.773, 15.323–15.410, and 17.004–17.229, respectively, which deviate from the values of the wall rocks, suggesting an external Pb source. The in‐situ LA‐ICP‐MS spot analyses of the pyrite reveals that gold occurs in two generations of pyrite (Py2 and Py3) but at low concentrations (≤0.06 ppm for Py2, ≤0.24 ppm for Py3). Visible gold, however, only occurs in the Stage II assemblage as inclusions in pyrite and quartz, and is distributed along the margins or within the fractures of the sulfides. The Py2 shows high Co, Ni, and As concentrations and is depleted in other trace elements typical of a magmatic‐hydrothermal derivation. In contrast, Py3 exhibits low concentrations in most trace elements. Trace element mapping of Py2 revealed correlations between Fe and Co, as well as Ni and As, indicating their couped substitution in the pyrite structure. The available geological, petrographic and geochemical data consistently suggest that the Xinfang gold deposit formed during the Early Cretaceous by hydrothermal fluids of magmatic contribution. [ABSTRACT FROM AUTHOR]

The newly discovered vein-type Shirengou gold deposit on the northern edge of the North China Craton contains at least 8.69 tons of Au at an average grade of 9.80 g/t. Six auriferous quartz veins have been identified within Upper Jurassic rhyolitic breccia-bearing crystal-lithic tuff, and they follow NW-trending secondary faults. Gold mineralization was closely related to silicification, with pyrite as the predominant ore mineral. Four mineralization stages can be discerned, involving Stage I milky quartz, Stage II quartz-pyrite, Stage III gray quartz-polymetallic sulfide, and Stage IV quartz-calcite ± pyrite. Zircon U Pb dating of a pre-ore porphyryritic rhyolite dike sets an upper age limit on the gold mineralization of ~131.1 Ma. Two-phase and single-phase aqueous inclusions were observed in quartz related to all four mineralization stages. From Stage I to Stage IV, the fluid inclusion homogenization temperatures decrease from respectively 257–340 °C to 230–277 °C, 201–250 °C and 161–200 °C, with corresponding salinities of 3.39–9.21, 2.24–8.00, 1.22–7.59, and 0.18–3.55 wt% NaCl equivalent, respectively. Thus, the ore-forming fluid can be described as moderate-high temperature, moderate-low salinity H 2 O-NaCl fluids. The δ34S values of sulfides vary from 0.0 to 5.3 ‰, indicating that the S was derived primarily from magmatic source(s), with some contribution from the metamorphic rocks of the surrounding Jianping Group. In-situ LA-ICP-MS trace element analysis of sulfides, together with our new age data, suggest that the ore-forming fluid was initially of Early Cretaceous magmatic-hydrothermal origin, and subsequently modified by interaction with the wall rocks of the Jianping Group, extracting the ore-forming metals from these rocks into the fluids. • Zircon U Pb geochronology confine the timing of gold mineralization after 131.1 Ma. • The ore-forming fluid formed in a H 2 O-NaCl hydrothermal system. • S isotope imply that S was derived from magmatic source with some from wall rock. • The ore-forming fluid was of magmatic-hydrothermal origin and modified by wall rock. • The Shirengou gold deposit was related to the Early Cretaceous magmatism. [ABSTRACT FROM AUTHOR]

The Zhilingtou polymetallic deposit, South China, provides an excellent opportunity to investigate the magmatic-hydrothermal evolution of the porphyry Mo to epithermal Au–Ag–Pb–Zn ore spectrum. New zircon U–Pb, sphalerite 40Ar/39Ar, and pyrite Rb–Sr ages, together with previous molybdenite Re–Os ages, indicate that the granitic magmatism and Mo–Au–Ag–Pb–Zn mineralization were coeval and cogenetic in the Early Cretaceous (~ 113 Ma). Fluid inclusions and H–O isotope results have established the evolution from an early high-temperature H2O–NaCl magmatic fluid system (Mo mineralization), to a medium-temperature mixed fluid system of magmatic and meteoric water (Au–Ag mineralization), to a peripheral late-stage low-temperature H2O–NaCl meteoric water fluid system (epithermal Au–Ag–Pb–Zn mineralization). Moreover, the sulfur isotopic compositions (δ34S = 2.1–7.8‰) of the sulfide minerals confirm a genetic link to the granitic magma. Lead isotope data from pyrite and the granite–rhyolite porphyries are similar, indicating that they share a common Pb source. The geochronological, geochemical, and isotopic lines of evidences consistently suggest that the porphyry Mo and epithermal Au–Ag–Pb–Zn mineralization formed in one magmatic–hydrothermal system. The porphyry-epithermal mineralization model for Zhilingtou has significant importance for prospecting work in South China, where Mo and associated Pb–Zn–Ag resources are abundant. [ABSTRACT FROM AUTHOR]

The Qingchengzi Pb–Zn–Au–Ag–Mo polymetallic ore field located in the Liaodong Peninsula, Liaoning Province, China, is spatially associated with multiple magmatism, which provide a classic example for studying the multiple tectonic and metallogenetic events. In this paper, we report some new geochemical and geochronological data of igneous rocks in the Qingchengzi ore field, including diabase, lamprophyre, microdiorite, granite porphyry, and quartz porphyry. Zircon U–Pb dating yielded the formation ages of these rocks as Triassic, Jurassic, and Early Cretaceous. Low‐Mg adakitic granite porphyries formed at 233 Ma have zircon εHf(t) values of −17.7 to −14.5, suggesting that they were mainly derived from partial melting of thickened lower crust. Mafic dykes formed during 226–203 Ma have zircon εHf(t) values of −28.6 to −12.8, suggesting that they were mainly derived from partial melting of ancient lithospheric mantle. Zircons from the 168Ma Jurassic diabase have high Nb/Ta and low Nb/Th ratios, with zircon εHf(t) values of −25.2 to −18.5. This suggests that ancient lithospheric mantle was influenced by melts/fluids from the subducted Palaeo‐Pacific Plate. The Early Cretaceous microdiorites (126 Ma) are high‐Mg adakite rocks, with zircon εHf(t) values of −27.3 to −19.6. Melting of delaminated eclogitic lower crust might produce these high‐Mg adakitic microdiorites. The upwelling asthenosphere could heat the residual lower crust to form the quartz porphyries. The Early Cretaceous diabase (100 Ma) shows low Nb/Ta and high Nb/Th ratios, with zircon εHf(t) values of −0.7 to 5.8, implying a depleted mantle source. The characteristics of Triassic–Cretaceous intermediate‐mafic intrusions show that the lithospheric mantle evolved from enriched ancient mantle to depleted juvenile mantle. This transformation of the lithospheric mantle might have resulted from the delamination of the lower crust that was caused by subduction of the Palaeo‐Pacific Plate. Based on the field observation and geochemical data, Au, Pb–Zn–Ag, Mo mineralization in the Qingchengzi ore field show closely spatial and genetic relationship with intrusive rocks, indicating that the Mo, Pb–Zn–Ag mineralization might be related to the Jurassic magmatic activity, whereas Au mineralization related to the Early Cretaceous magma. [ABSTRACT FROM AUTHOR]

The propagation of hydraulic fracture in elastic rocks has widely been investigated. In the paper, we shall focus on numerical modeling of hydraulic fracturing in a class of porous rocks exhibiting plastic deformation. The plastic strain of porous rocks is described by a non-associated plastic model based on Drucker–Prager criterion. The plastic deformation is coupled with fluid pressure evolution described by the lubrication theory. An extended finite element method is used for modeling the propagation of fracture. The fracture propagation criterion is based on the J-integral. The proposed numerical model is validated by comparisons with numerical and analytical results. The influence of plastic deformation on fracture propagation process is investigated. [ABSTRACT FROM AUTHOR]

Compared to other Mo provinces, few studies focused on the South China Mo Province (SCMP), especially for Early Cretaceous Mo mineralization. The Lufeng porphyry Mo deposit in the SCMP is characterized by disseminated and veinlet‐type mineralization in granite porphyry, gneiss, and rhyolite. In this study, six molybdenite samples yield a Re–Os isochron age of 108.0±1.8 Ma, which is consistent with the zircon U–Pb age of the granite porphyry (108.4±0.8 Ma). The coincidence of magmatic and hydrothermal activities indicates that Mo mineralization was associated with the intrusion of granite porphyry during the late Early Cretaceous. A compilation of U–Pb and Re–Os chronological data suggests that an extensive and intensive Mo mineralization event occurred in the SCMP during the late Early Cretaceous. The marked difference in molybdenite Re contents between Cu‐bearing (85–536 ppm) and Cu‐barren (1.3–59 ppm) Mo deposits of the late Early Cretaceous indicates that the ore‐forming materials were derived from strong crust–mantle interactions. Together with regional petrological and geochemical data, this study suggests that late Early Cretaceous Mo mineralization in the SCMP occurred in an extensional setting associated with the roll‐back of the Paleo‐Pacific slab. [ABSTRACT FROM AUTHOR]

• A 3D hydro-mechanical coupled model is presented to study hydraulic fracturing interaction with bedding planes. • Cohesive zone method is employed to represent the bedding planes explicitly. • Fracture propagation behaviors are analyzed under different patterns. Bedding planes are abundant in the continental shale oil reservoirs, but their impact on hydraulic fracturing is still not fully understood. To investigate the effects of stress condition, bedding plane's properties and layer lithology on hydraulic fracture propagation in layered formation, a 3D hydro-mechanical coupled model is presented. The bedding planes are explicitly represented by cohesive elements with degraded properties compared to the rock. The results show that increasing the stress difference ratio of the vertical principal stress to horizontal principal stress promotes the hydraulic fracture propagating across bedding planes, and the critical value of vertical principal stress required for hydraulic fracture crossing rises with the decrease of bedding plane's critical traction. Furthermore, when the critical traction ratio of bedding plane to rock drops below 0.7, the fracture propagation pattern changes from crossing to deflecting. Additionally, the extension pressure increases slightly, the fracture length decreases and the area of opening bedding planes rises. As the permeability of bedding plane increases, the fracture cannot cross the bedding planes and even stops extension. The layer lithology contrast also affects fracture propagation patterns. This study examines the fracture propagation behaviors under different patterns, including the opening morphology of bedding plane and the evolution of injection pressure and strain energy. The simulation results may provide useful insights for hydraulic fracturing design in layered formations. [ABSTRACT FROM AUTHOR]

The Liaodong Peninsula in northeast China hosts visible and invisible Au-dominated mineralization. Compared with visible Au, age and mechanisms of invisible Au-dominated mineralization are still unclear. The Linjiasandaogou deposit in the Liaodong Peninsula comprises disseminated and veinlet ores hosted in Paleoproterozoic schist and Triassic granite porphyry and lamprophyres. Three mineralization stages were identified in this deposit: the early pyrite (Py1), arsenian pyrite (Py2)–arsenopyrite–sphalerite (Sp1)–quartz–apatite, and freibergite–sphalerite (Sp2)–galena–quartz stages. Gold mineralization is mainly in invisible forms and was deposited during the second stage, whereas Ag was deposited during the third stage. Uranium-Pb dating of hydrothermal apatite from the second stage indicates that Au mineralization occurred at ca. 184 Ma, when the Yaojiagou granite was emplaced. In situ S isotope analysis shows that sulfides which formed during the mineralization stages have a narrow range of δ34S V-CDT values (4.80 ‰–8.53 ‰) that are typical of a magmatic–hydrothermal system. Py2 has higher As, Au, and Ag contents of 15,100–95,576, 15.4–183, and 20.8–129 ppm, as compared with Py1 (As <0.9–11,050 ppm, Au <0.03–11.1 ppm, and Ag <0.05–48.5 ppm). The negative correlations between As–S and Au–Fe in pyrite are indicative of As substitution for S and Au substitute for Fe in the pyrite. The pyrite and sphalerite trace element compositions indicate that the formation temperatures of the three stages were >250 °C, 154–252 °C, and 167–197 °C, respectively. The evolution of the hydrothermal system indicates that the deposition of Au is due to cooling and fluid-rock interaction, whereas the precipitation of Ag results from an increase in the sulfidation state. Results suggest the invisible Au-dominated mineralization in the Linjiasandaogou deposit was associated with the Early Jurassic intrusion. This study supplements the ore-forming epoch framework of the Qingchengzi ore field and improves the understanding of the Au–Ag mineralization in this area. • Apatite in situ dating yields an invisible Au-dominant mineralization age of ca. 184 Ma. • Au, Ag, and Cu substitute Fe in pyrite. • Fluid-rock interaction and fluid cooling result in the precipitation of Au-bearing pyrite. [ABSTRACT FROM AUTHOR]

The Caosiyao giant porphyry Mo deposit (1.76 Mt), which is the third largest such deposit in China, is located on the northern margin of the North China Craton and associated with the Caosiyao intrusive complex that was emplaced in Archaean metamorphic rocks. The intrusive complex consists of monzogranite and coarse‐, medium‐, and fine‐grained granite porphyries that yield U―Pb ages of 148.5 ± 1.2, 146.4 ± 1.0, 144.6 ± 1.0, and 142.8 ± 3.2 Ma, respectively. Four molybdenite Re―Os model ages range from 143.1 ± 2.4 to 145.3 ± 2.1 Ma, which are consistent with the U―Pb ages for the igneous complex. The geochronological data indicate that the multistage magmatic‐hydrothermal processes were important in the formation of the Caosiyao giant deposit. The rocks of the Caosiyao granitic complex have high contents of silica (SiO2 = 71.7–75.6 wt.%) and total alkalis (mostly K2O + Na2O > 8 wt.%), low contents of CaO and MgO, and exhibit peraluminous high‐K calc‐alkaline to shoshonitic affinities. They are enriched in large‐ion lithophile elements (e.g., K, Rb, U, and Th) and light REEs and depleted in Eu, Ba, Sr, Nb, P, and Ti. The geochemical characteristics indicate advanced fractional crystallization and that the rocks are strongly fractionated I‐type granites. The negative Hf isotopic compositions of the granitic rocks, combined with old two‐stage Hf model ages, indicate the magmas were derived from partial melting of the ancient lower crust of the North China Craton. All the intrusive rocks in the complex have relatively high Ce4+/Ce3+ ratios and oxygen fugacity, which would have facilitated Mo extraction into the melts owing to the much higher solubility of S as sulphate (SO42−) than sulphide (S2−). The magma crystallization temperatures decreased from 882°C to 770°C as the magma evolved. The multistage magmatic‐hydrothermal processes, and the prolonged fractional crystallization, combined with high magma oxygen fugacity are the key factors to form the Caosiyao giant Mo deposit. The tectonic setting of deposit formation was one of extension related to rollback of the subducting Palaeo‐Pacific Plate during the Late Jurassic to Early Cretaceous. [ABSTRACT FROM AUTHOR]

Brain injury associated with deep hypothermic circulatory arrest (DHCA) has been recognized in patients with congenital heart diseases and those undergoing aortic arch surgeries. However, the preclinical investigation of long‐term cerebral injury and recovery mechanisms related to DHCA has been restricted to a satisfactory recovery animal model with a determined recovery time. This study aimed to evaluate the feasibility of a long‐term surviving DHCA model without blood priming in rats, in order to investigate the pathophysiology of long‐term complications in further studies. Twelve Sprague‐Dawley rats were divided into 2 groups: sham group (n = 3) and DHCA group (n = 9). The DHCA group was further assigned to the surviving time of postoperative day 2, 14, and 30 (n = 3, respectively). The entire cardiopulmonary bypass (CPB) circuit consisted of a modified reservoir, a custom‐designed small‐volume membrane oxygenator, a roller pump and a heater/cooler. A 24‐G catheter was cannulated in the branch of the left femoral artery for arterial blood pressure monitoring. Cardiopulmonary bypass was established via the right external jugular vein–right atrium and tail artery. Rats were cooled to a rectal temperature of 18°C, followed by 30 minutes of DHCA with global ischemia. After re‐warming for approximately 40 minutes, the animals were weaned from the CPB at 35.5°C. Blood gas and hemodynamic parameters were recorded preoperatively and intraoperatively, and at 2, 14, and 30 days postoperatively. Thereafter, the brains were perfusion fixed and histologically analyzed. All DHCA processes were successfully achieved, and none of the rats died. Blood gas analysis and hemodynamic parameters at each time point were normal, and vital signs of all rats were stable. Histopathologic deficits in the hippocampus (pathological score, surviving hippocampal neurons, and Ki67‐positive neurons) manifested after 30 minutes of DHCA, which persisted for at least 14 days and recovered after 30 days. A novel and simple long‐term recovery model of DHCA in rats was established in the present study, and histopathologic deficits were observed after clinically relevant 30‐minute DHCA durations, in order to determine the 30‐day recovery time frame. [ABSTRACT FROM AUTHOR]

Key message: Co-localization of a major QTL for wheat stripe rust resistance to a 3.9-cM interval on chromosome 6BL across both populations and another QTL on chromosome 2B with epistatic interaction. Cultivars with diverse resistance are the optimal strategy to minimize yield losses caused by wheat stripe rust (Puccinia striiformis f. sp. tritici). Two wheat populations involving resistant wheat lines P10078 and Snb"S" from CIMMYT were evaluated for stripe rust response in multiple environments. Pool analysis by Wheat660K SNP array showed that the overlapping interval on chromosome 6B likely harbored a major QTL between two populations. Then, linkage maps were constructed using KASP markers, and a co-localized locus with large effect on chromosome 6BL was detected using QTL analysis in both populations. The coincident QTL, named QYr.nwafu-6BL.2, explained 59.7% of the phenotypic maximum variation in the Mingxian 169 × P10078 and 52.5% in the Zhengmai 9023 × Snb"S" populations, respectively. This co-localization interval spanning 3.9 cM corresponds to ~ 30.5-Mb genomic region of the newest common wheat reference genome (IWGSC RefSeq v.1.0). In addition, another QTL was also detected on chromosome 2B in Zhengmai 9023 × Snb"S" population and it can accelerate expression of QYr.nwafu-6BL.2 to enhance resistance with epistatic interaction. Allowing for Pst response, marker genotypes, pedigree analysis and relative genetic distance, QYr.nwafu-6BL.2 is likely to be a distinct adult plant resistance QTL. Haplotype analysis of QYr.nwafu-6BL.2 revealed specific SNPs or alleles in the target region from a diversity panel of 176 unrelated wheat accessions. This QTL region provides opportunity for further map-based cloning, and haplotypes analysis enables pyramiding favorable alleles into commercial cultivars by marker-assisted selection. [ABSTRACT FROM AUTHOR]

Abstract The Early–Middle Jurassic tectonic setting of NE China is poorly defined. Mineralization of this period, especially skarn–porphyry mineralization and the ore-related magmatism, can provide well constraints on the geodynamic setting. An analysis of the spatio-temporal distribution of skarn–porphyry deposits in NE China, with the Sankuanggou skarn Fe–Cu–(Mo) deposit chosen as a typical example, was conducted in an attempt to elucidate the tectonic setting of the region. The Sankuanggou deposit is located in the Great Xing'an Range, in the eastern segment of the Central Asian Orogenic Belt. Re-Os isochron dating of molybdenites indicates the ages of the skarn- and veinlets–disseminated-type mineralization are 172.9 ± 3.3 and 173.4 ± 6.3 Ma, respectively. This suggests that the mineralization was contemporaneous with emplacement of granodiorite (175.9 ± 1.6 Ma), and related to Early Jurassic magmatism. Zircons from the Sankuanggou granodiorite have ε Hf (t) values of +8.7 to +11.2. Sulfur isotopic compositions (δ34S) of the sulfides range from −3.59‰ to +0.92‰, indicating that the ore-forming materials were mainly derived from magma. The Re content of molybdenite (11.3–63.3 ppm) suggests that the ore-forming materials mainly originated from a mixed crust–mantle source. Geochemical characteristics and Sr–Nd–Pb–Hf isotopic compositions suggest that the ore-forming granodiorite was formed in a continental arc setting, melts of which largely originated from partial melting of a mantle wedge induced by the subducted slab. Based on the spatio-temporal distribution of the skarn–porphyry deposits in NE China, we propose that the Early–Middle Jurassic period (200–160 Ma) is likely to have been one of the most important metallogenic epochs in NE China. These deposits formed in a continental arc setting, which was closely related to the westward subduction of the paleo-Pacific Plate during this period. Graphical abstract Unlabelled Image Highlights • The Sankuanggou Fe–Cu–(Mo) mineralization formed during the Early–Middle Jurassic. • Ore-related granodiorite was generated by partial melting of the mantle wedge induced by paleo-Pacific Plate subduction. • The ore-forming materials were mainly derived from a magmatic source, with both mantle and crustal materials involved. • The Early–Middle Jurassic skarn–porphyry mineralization in NE China occurred under a continental arc setting. • The Early–Middle Jurassic mineralization in NE China is related the westward subduction of the paleo-Pacific Plate. [ABSTRACT FROM AUTHOR]

The Xing-Meng Orogenic Belt (XMOB) hosts significant Au-dominant polymetallic mineral deposits. Although these deposits mostly formed in the Mesozoic, Permian Au deposits are also present but less well studied. In the Bilihe and Hadamiao gold mining areas, granitic intrusions that are associated with gold mineralization were dated by LA-ICP-MS at 272.7-259.7 Ma. These intrusions consist of granodioritic porphyry and quartz diorite that both represent calc-alkaline metaluminous I-type granites. These granitoids exhibit enrichment in LREEs and LILEs, depletion in HREEs and HFSEs, and low Sr/Y ratios, suggesting that these rocks have an island-arc affinity. The εHf(t) values of the Bilihe granodioritic porphyry and Hadamiao quartz diorite range from −0.3 to +8.9, with TDM2 values ranging from 0.7 to 1.3 Ga, and from +2.5 to +13.5, with TDM2 values ranging from 0.4 to 1.1 Ga, respectively. The zircon δ18O values of the granitic porphyry and quartz diorite range from 6.9 to 7.6‰ and from 5.0 to 6.4‰, respectively. A simple binary Hf-O isotope mixing model shows that the assimilation of 10-15% sediments by MORB could have generated the Bilihe granodioritic porphyry, and that the assimilation of less than 5% sediments by MORB could have generated the Hadamiao quartz diorite. Combined with previous studies of the Late Carboniferous to Permian igneous rocks in the southern region of the XMOB, these new data suggest that the Bilihe and Hadamiao ore-related intrusive rocks formed in a continental-arc setting associated with the subduction of the Paleo-Asian oceanic slab. This setting indicates the potential existence of subduction-related gold deposits that are related to contemporaneous igneous activity. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The fluids were derived from magma and characterized by high temperatures, high salinities, and abundant CO 2. • The Mo mineralization occurs within the phyllic zone. Sericitization has a significant effect on fluid compositions. • Fluid immiscibility was the dominant mechanism for the deposition of ore-forming materials. Abstract The newly discovered Dasuji Mo deposit is located on the northern margin of the North China Craton, and the Mo mineralization is related to Triassic granite porphyry and quartz porphyry. Alteration associated with the deposit includes silicification, sericitization, chloritization, K-feldspathization, kaolinitization, carbonatization, and fluoritization. The silicification and sericitization (phyllic alteration) are closely related to the Mo mineralization. Based on mineral assemblages and cross-cutting relationships, the hydrothermal ore-forming process can be divided into four stages: stage 1 is characterized by K-feldspathization with minor molybdenum mineralization; stage 2 is the main stage of molybdenum mineralization; stage 3 is involved in lead-zinc mineralization; and stage 4 is characterized by no mineralization. Four types of fluid inclusions are recognized: liquid-rich, gas-rich, CO 2 -H 2 O, and daughter-mineral-bearing. Microthermometric data show a decrease in homogenization temperatures and salinities from the early to late stages, so that stages 1–4 show homogenization temperatures of 468–375, 435–271, 318–206, and 222–142 °C, respectively, and the fluids of stages 1, 3, and 4 had salinities of 2.57–16.50 (along with a few high-salinity inclusions: 32.04–48.05), 0.88–11.19, and 0.88–7.45 wt% NaCl equiv., respectively. The salinities of stage 2 fluid inclusions have a bimodal distribution: 1.40–17.48 and 29.20–53.25 wt% NaCl equiv. Laser ablation inductive coupled plasma mass spectrometer (LA-ICP-MS) analyses show that the fluid compositions are dominated by Na, K, Fe, and Mn. In stage 2 fluid inclusions, the Mo concentrations vary over a range of more than one order of magnitude (more than for any other element) as a result of fluid-rock interactions and molybdenite precipitation. Cu concentrations remain always relatively high in the fluids during their evolution (26–7092 ppm) because there was little chalcopyrite precipitation. The stage 3 fluid inclusions are rich in Mn, Pb, and Zn, while Ag concentrations increased in stage 3 and 4 fluid due to the addition of meteoric water from the surrounding rock. Reactions between the wallrock and hydrothermal fluids affected the composition of the hydrothermal fluids; sericitic alteration in particular had a great effect on fluid compositions, manifesting the variety of the content of Sr, Ba, Ca, Pb. The ore-forming fluids were mainly magmatic-hydrothermal fluids that were mixed with meteoric water during stages 3 and 4. Fluid immiscibility, a rapid decrease in pressure, fluid-rock reactions and fluid cooling were collectively responsible for the sulfide precipitation in the Dasuji deposit. [ABSTRACT FROM AUTHOR]

Abstract The Dasuji porphyry Mo deposit is located at the northern margin of North China Craton. Mo mineralization occurs mainly within the intrusions of alkali feldspar granite, granite porphyry, and quartz porphyry, which yield weighted mean 206Pb/238U ages (2σ) of 227.6 ± 1.5, 225.7 ± 1.5, and 224.3 ± 1.8 Ma, respectively. These ages are indistinguishable to the molybdenite Re Os isochron age of 223.9 ± 1.5 Ma (2σ). The Dasuji granites show the petrological, mineralogical, geochemical, and geotectonic characteristics of A-type granites. They exhibit low negative εNd(t) values (−16.7 to −12.6) with corresponding T DM2 (Nd) ages of 1705–2000 Ma, variable but mainly negative εHf(t) values (mostly −21.0 to −7.9) with corresponding T DM2 (Hf) ages of 1715–2728 Ma, and Pb isotopic compositions indicating that the primary magmas were dominantly derived from partial melting of ancient lower crust. In chondrite- and mantle-normalized trace element diagrams, all the granitic rocks show negative anomalies in Ba, Sr, and Eu, and a positive anomaly in Pb. The ratios of LREE/HREE, and (La/Yb) N and δEu values decrease from the alkali feldspar granite to the granite porphyry and quartz porphyry. These data are attributed to fractional crystallization processes. Fractionation of feldspar, biotite, and possibly K-feldspar produced the variations in major elements and Rb, Sr and Ba, and the distribution of REE are controlled mainly by fractionation of zircon, allanite, minor apatite, and possibly a small quantity of monazite. Together with the regional geology, the data infer that the Dasuji porphyry Mo deposit formed in a post-collision extensional setting during the Late Triassic. Graphical abstract Unlabelled Image Highlights • Ore-related Dasuji granites are formed between 227.6 and 224.3 Ma. • The primary magmas were derived from partial melting of ancient lower crust, with a minor mantle contribution. • The magma experienced at least two stages of fractional crystallization. • The Dasuji granites are A-type granites. [ABSTRACT FROM AUTHOR]

Abstract With the increasing demand of oil and gas resource, the development of deep reservoir has become an inevitable trend. To investigate the coupled effects of rock elasto-plastic deformation, fluid flow and heat transfer in the process of hydraulic fracturing of deep reservoir, the mathematical model of elasto-plastic hydraulic fracture propagation is established based on cohesive zone model (CZM) and embedded discrete fracture model (EDFM). The constitutive equation incorporating thermal stress is derived by using Drucker-Prager yield condition and the associated flow law. Fluid flow in the fracture is modeled with lubrication theory. The thermal non-equilibrium theory is employed to describe the heat exchange between rock matrix and fluid in the fracture based on EDFM. The CZM is used as fracture propagation criterion. The rock deformation equation is solved by finite element method. The temperature field and fluid flow in the fracture are discretized by finite volume method. Due to the non-linearity of flow equation, the iterative method is used to solve the coupled problem of stress, pressure and temperature fields. A Triangular-PEBI (Perpendicular Bisector) dual mesh system is presented for numerical implementation. The numerical model is validated against with analytical solution and other methods in the literature. The results show the significance of accounting for elasto-plastic deformation and heat transfer when simulating hydraulic fracture propagation in deep reservoir. Highlights • Developed model involves plastic deformation, fluid flow and temperature field. • Heat exchange between matrix and fracturing fluid is modeled based on EDFM. • A Triangle-PEBI dual mesh system is presented for numerical implementation. • An efficient algorithm for thermal-elasto-plastic fracture propagating is proposed. • Result shows that plastic zone moves forward and expands during propagating. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The ore-forming fluids formed in a H 2 O-CO 2 -NaCl ± CH 4 ± N 2 hydrothermal system. • H-O isotopes indicate that the ore-forming fluid was derived from magmatic water. • S-Pb isotopes suggest that the ore-forming material was derived from a magmatic source. • LA-ICP-MS data show that abundant Au mineralization occurred during the middle hydrothermal stage. • High Co/Ni ratios of pyrite are consistent with a hydrothermal origin. • The Wulong gold deposit may be classified as an intrusion-related gold deposit. Abstract The Wulong vein-type gold deposit, located along the northeastern margin of the North China Craton (NCC), contains > 80 tonnes of gold at an average grade of 5.35 g/t. A total of 380 auriferous quartz veins are hosted in Late Jurassic gneissic two-mica granite and Early Cretaceous granodiorite. A paragenetic sequence, representing three hydrothermal stages, has been identified: (1) quartz ± pyrite; (2) quartz-polymetallic sulfide; and (3) quartz-calcite ± pyrite. Petrography, fluid inclusion microthermometry, and laser Raman spectroscopy revealed three types of fluid inclusions: CO 2 ± CH 4 (type I), H 2 O-CO 2 ± CH 4 (type II), and H 2 O-NaCl (type III). Fluid inclusion data indicate that during mineralization, fluid temperatures evolved from 283 to 395 °C to 219–328 °C to 144–255 °C, and salinities varied from 0.70 to 8.95 wt% to 0.18–7.86 wt% to 0.18–4.96 wt% NaCl equivalent. Quartz yielded δ18O H2O-SMOW and δD SMOW values of 0.9–7.3‰ and −65‰ to −48‰, respectively, indicating that the ore-forming fluids were derived from magmatic water and mixed with meteoric water during the later stages of mineralization. Sulfides have δ34S CDT sulfur isotopic compositions ranging from 0.9‰ to 3.9‰, suggesting that the S was derived from a magmatic source. Pb isotopic compositions of sulfides (206Pb/204Pb = 17.488–17.718, 207Pb/204Pb = 15.565–15.631, and 208Pb/204Pb = 38.190–38.766) indicate that the Pb was derived primarily from the upper crust, with minor input from the mantle. In situ laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) trace element analyses of three generations of pyrite (Py1, Py2, and Py3) reveal that gold concentrations in Py2 are higher than those in Py1 and Py3, which indicates that gold mineralization occurred primarily during the middle stage. High Co/Ni ratios of pyrite are consistent with a hydrothermal origin. We suggest that the Wulong gold deposit formed during lithospheric thinning associated with destruction of the NCC, this process was triggered by subduction of the Paleo-Pacific plate during the Early Cretaceous. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The Ce4+/Ce3+ ratios of zircon from ore-related intrusions show a positive correlation with the size of deposits. • The Ce4+/Ce3+ ratios of 300, 200 and 100 separate the intrusions into superlarge, large, medium and small-sized deposits. • ΔFMQ + 2 discriminates the intrusions associated with medium to superlarge-sized deposits from small-sized deposits. Abstract The East Xing'an–Mongolian Orogenic Belt (EXOB) in China hosts numerous porphyry Mo deposits that are associated with calc-alkaline granitic intrusions. Here we report the trace-element compositions of zircon grains from 11 intrusions collected from 8 porphyry Mo deposits in the EXOB: the superlarge-sized Daheishan and Luming deposits; the large-sized Aolunhua deposit; the medium-sized Kulitu and Yangchang deposits; and the small-sized Erbadi, Hashitu, and Longtoushan deposits. The results show a positive correlation between the Mo tonnage of each deposit and the zircon Ce4+/Ce3+ ratio of the ore-related intrusions. In addition, the Ce4+/Ce3+ ratio of zircon in ore-related intrusions is much higher than that of the associated barren rocks. The Ce4+/Ce3+ ratios of 300, 200 and 100 of zircon seem to separate the intrusions into superlarge-sized, large-sized, medium-sized and small-sized porphyry Mo deposits, respectively. Oxygen fugacity values of ΔFMQ +2 of ore-related intrusions discriminate the medium-sized to superlarge-sized Mo deposits from the small-sized deposits. The relationship between the scale of mineralization and oxygen fugacity suggests that the oxidation condition of the source magma played a critical role in the development of large-sized and superlarge-sized Mo porphyry systems in the EXOB. The zircon Ce4+/Ce3+ ratios of ore-related intrusions of the EXOB are similar to those of porphyry Cu deposits in the Central Asian Orogenic Belt and the Yulong copper belt, but much lower than those of the Chuquicamata porphyry Cu deposit in Chile. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The Lesser Xing'an–Zhangguangcai Range is the most important Mo ore belt in the CAMD. • The giant Mo deposits developed multiple Mo-bearing hydrothermal fluid activities. • The ore-forming fluids of the giant porphyry Mo deposits were mainly crustal fluids. Abstract The Lesser Xing'an Range–Zhangguangcai Range metallogenic belt, located at the eastern segment of the Central Asian metallogenic domain, hosts two giant Mo porphyry deposits, the Early Jurassic Luming deposit and the Middle Jurassic Daheishan deposit. In this study, the He–Ar and S isotopic compositions of sulfides from different hydrothermal stages of the Daheishan and Luming deposits were determined. Fluid inclusions hosted in pyrites shown that 3He/4He ratios of the Luming and Daheishan deposit range from 0.02 to 0.32 Ra, and 0.7 to 2.5 Ra, respectively. 40Ar/36Ar ratios of the Luming and Daheishan deposit range from 313.3 to 535.1, and 309.9 to 360.6, respectively. He and Ar isotopic compositions suggest that the ore-forming fluids of the Luming deposit are mainly crustal-derived fluids, with near atmospheric Ar and crustal He values. Mantle-derived fluids are a minor component. In contrast, the ore-forming fluids of the Daheishan deposit are a mixture between a crust-derived fluid and a mantle-derived fluid. The δ34S values of the sulfide samples from the Luming deposit (4.98–7.14‰) and the Daheishan deposit (1.83–2.88‰) indicate that the sulfur in the ore-forming fluids was primarily derived from granitic magma. The isotopic compositions across the stages within one deposit have no variability. The similar He–Ar and S isotopic compositions of the sulfides from the different Mo-bearing hydrothermal stages of these two giant Mo deposits indicate that the overprinting of the multiple stages of Mo-bearing hydrothermal fluids may be a key factor in the formation of giant porphyry Mo deposits. Meanwhile, the westward subduction of the Paleo-Pacific plate might have played an important role for the formation of the giant Mo deposits in the Lesser Xing'an Range–Zhangguangcai Range metallogenic belt. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • There are Early and Middle Jurassic intrusions in the Daheishan ore district. • The Early Jurassic rocks were formed in a subduction zone setting. • The Middle Jurassic rocks were associated with over-thickened continental crust. • The long-lasting magmatism and dehydration contribute to the Mo mineralization. Abstract Two types of Jurassic intrusive rocks have been recognized in the Daheishan ore district, northeastern China, according to new SIMS zircon U–Pb ages, whole-rock major and trace element abundances, and Sr–Nd–Pb isotopic compositions. The first type is represented by biotite granite and monzogranite, with zircon U–Pb dating yielding ages from 182 to 175 Ma. These rocks are high-K calc-alkaline series, and span from metaluminous to weakly peraluminous. They exhibit enrichment in large ion lithophile elements (LILEs) and depletion in high field strength elements (HFSEs), with significant negative Eu anomalies, low (La/Yb) N and Sr/Y ratios. They have low (87Sr/86Sr) i ratios of 0.70202–0.70474, positive ε Nd (t) values of 1.7–2.3, and Nd model ages (T DM2) of 826–771 Ma as well as (206Pb/204Pb) i values of 18.400–18.494. These arc-like geochemical characteristics suggest that the Early Jurassic intrusions were formed by the partial melting of a mixture of dominated juvenile component and pre-existing crust in a subduction zone setting. The second type is represented by diorite and granodiorite, with zircon U–Pb ages of 172–170 Ma. These Middle Jurassic intrusive rocks are high-K calc-alkaline and mainly metaluminous, with high Mg# (>29) and elevated (La/Yb) N and Sr/Y ratios. They display similar whole-rock Sr–Nd–Pb isotopic compositions ((87Sr/86Sr) i = 0.70432–0.70480, ε Nd (t) = 1.7–2.3, (206Pb/204Pb) i = 18.3016–18.4531) to the Early Jurassic granites. Their adakitic geochemical compositions suggest that they formed at pressures greater than 15 kbar by the partial melting of thickened lower crust with a juvenile component. We further propose that the tectonic setting of the Zhangguangcai Range in the Early Jurassic might be a back-arc related to the subduction of the Paleo-Pacific Plate, and that subduction stopped temporarily in the Middle Jurassic due to the presence of over-thickened continental crust. The prolonged Jurassic adakitic magmatism and concomitant fluid activities may have played important roles in the formation of the porphyry Mo deposits in the Daheishan ore district. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The Beishan monzogranitic pluton was emplaced at 194.75 ± 0.81 Ma. • Molybdenite Re-Os dating defines an isochron age of 194.0 ± 2.0 Ma. • The Beishan monzogranite was derived from partial melting of juvenile lower crust. • Dongfengbeishan porphyry Mo deposit was related to westward subduction of the paleo-Pacific plate. Abstract The Dongfengbeishan porphyry Mo deposit is located to the southeast of the Lesser Xing'an Range–Zhangguangcai Range metallogenic belt in NE China. LA–ICP–MS zircon U–Pb dating of the Beishan monzogranite yields an age of 194.75 ± 0.81 Ma. Five molybdenite samples define a Re–Os isochron age of 194.0 ± 2.0 Ma, suggesting that mineralization was associated with emplacement of the Beishan monzogranitic pluton. Monzogranite samples are classified as high-K calc-alkaline and are relatively enriched in light rare earth elements, depleted in heavy rare earth elements, Nb, Ba, P, Sr, Ti, and Zr, and yield negative Eu anomalies. These characteristics are interpreted to record fractional crystallization of the parental magmas. Zircon ε Hf (t) values for Beishan monzogranite samples range from +8.2 to +15.9, and two-stage model ages (T DM2) range from 217 to 711 Ma, indicating that the parental magma was produced during partial melting of juvenile lower crust. Combined with previous studies, our data suggest that the Dongfengbeishan porphyry Mo deposit was associated with westward subduction of the paleo-Pacific plate in the Early Jurassic. [ABSTRACT FROM AUTHOR]

The Daheishan porphyry Mo deposit in Jilin Province, NE China, is classified as a giant porphyry deposit with a total reserve of 1.87 Mt. @0.07% Mo. It is located within the Lesser Xing'an-Zhangguangcai Ranges at the eastern part of Central Asian Orogenic Belt, which was tectonically shaped by both the Paleo-Asian Ocean and the Paleo-Pacific Ocean regimes. The Mo mineralization (167 Ma) is related to the Daheishan intrusive complex which comprises of the barren Changgangling biotite granodiorite (177.9 Ma), the fertile Qiancuoluo biotite granodiorite (169.9 Ma) and the Qiancuoluo granodioritic porphyry (166.6 Ma). The Daheishan intrusive complex is high-silica, alkali-rich, metaluminous to slightly peraluminous in composition, belonging to high-K calc-alkaline series. In addition, they are characterized by enrichment in large ion lithophile elements (LILEs, e.g. K, Rb, Ba, Sr, U and Th) and light rare earth elements (LREEs), and relative depletion in high-field strength elements (HFSEs, e.g. Nb, Ta, P and Ti), suggesting the formation in oceanic arcs above subduction zones and an involvement of the oceanic component. The Sr-Nd-Pb isotopic compositions ( 87 Sr/ 86 Sr = 0.705413–0.707889, ε Nd (t) = −1.28 to +0.92, and 206 Pb/ 204 Pb = 18.44–18.73) of the Daheishan intrusive complex are consistently comparable to values of the regional mantle derived rocks, suggesting a source of depleted mantle wedge for the magmas. The trace element signatures, i.e. Th/Ce, Th/Sm, Th/Yb and Ba/La ratios, identify a minor (~4%) contribution of slab melts that metasomatized the mantle magma source. Geochemical particularity, i.e. high water content and oxygen fugacity, has been recorded at both bulk rock and mineral scales to account for the fertility of magmas of the Qiancuoluo granodioritic porphyry and Qiancuoluo biotite granodiorite relative to the barren Changgangling biotite granodiorite. The mineralization of the Daheishan supergiant porphyry Mo deposit, in association with the intrusion of contemporaneous granitoids in the region, was formed in an active continental margin environment due to the subduction of Mudanjiang Ocean between the Jiamusi and Songliao blocks in the early Jurassic, which, in a larger framework, was driven by the westward subduction of the Palaeo-Pacific Ocean. Under the subduction environment, an input of slab melts, which secured abundant molybdenum from the shales overlying the oceanic plate, is proven to have improved the fertility of primary magmas by comparing the geochemical compositions of the fertile and barren granitoids (porphyry Mo mineralization related-) in the Lesser Xing'an-Zhangguangcai Ranges. To conclude, factors such as contribution of slab melts, high water content and high oxygen fugacity, are regarded to be crucial for generating fertile magmas for porphyry Mo mineralization in the Lesser Xing'an-Zhangguangcai Ranges. [ABSTRACT FROM AUTHOR]

The Xinxing Pb–Zn–(Ag) deposit is located in the southeastern segment of the Lesser Xing’an–Zhangguangcai metallogenic belt, NE China. It is a small-scale deposit (Pb + Zn < 50,000 tonnes) that occurs in a crypto-explosive breccia pipe. Ore bodies are hosted in Permian granodiorite, structurally controlled by three sets of faults. This paper reports results of Rb–Sr isotopic dating of sphalerite, which yields an isochron age of 182.8 ± 3.1 Ma (MSWD = 1.02). The concentrations of Rb and Sr in sphalerite range from 0.0839 × 10 −6 to 0.7124 × 10 −6 and 0.4775 × 10 −6 to 7.4810 × 10 −6 , respectively. The initial 87 Sr/ 86 Sr ratio of sphalerite is 0.710954 ± 0.000061, indicating that the ore-forming components were derived from a mixed crust–mantle source. Sulfur isotopic values of the sulfides vary in a narrow range from −4.4% to −2.0% (av. of −3.28%), indicating a magmatic source for the sulfur. Lead isotopic compositions of the sulfide minerals ( 206 Pb/ 204 Pb = 18.277–18.323, 207 Pb/ 204 Pb = 15.514–15.571, 208 Pb/ 204 Pb = 38.016–38.199) are relatively consistent and cluster together between the mantle and orogenic belt lines, but are closer to the latter, reflecting the mixing of mantle-derived and minor crust-derived materials. These results, combined with the region geology, indicate that the Xinxing Pb–Zn–(Ag) deposit resulted from regional tectono-magmatic metallogenic processes that were related to the westward subduction of the Pacific plate underneath Eurasia in the Early Jurassic. [ABSTRACT FROM AUTHOR]

In this study, an efficient hydro-mechanical model of hydraulic fracture propagation is proposed using the embedded discrete fracture model in conjunction with the extended finite element method. Fracture is embedded into a common computational grid for both stress and pressure fields. A hybrid scheme of fixed stress split and Picard iterative method is presented to deal with the hydro-mechanical coupling and fracture propagation. The model is verified against other numerical solution of hydro-mechanical coupling problem and analytical solution of fracture propagation available from literature. Numerical results show that as matrix permeability increases, more fracturing fluid is required to get a desired length of fracture. The effect of Biot's coefficient is similar to that of matrix permeability. Finally, the model is extended to simulate simultaneous propagation of multiple hydraulic fractures. It's interesting to find that the effect of stress shadowing could be weakened by the poroelastic stress when accounting for hydro-mechanical coupling. The study indicates that the hydro-mechanical coupling could have significant influence on hydraulic fracturing, especially for multi-cluster fracturing of horizontal wells. [ABSTRACT FROM AUTHOR]

Key message: NGS-assisted super pooling emerging as powerful tool to accelerate gene mapping and haplotype association analysis within target region uncovering specific linkage SNPs or alleles for marker-assisted gene pyramiding.Abstract: Conventional gene mapping methods to identify genes associated with important agronomic traits require significant amounts of financial support and time. Here, a single nucleotide polymorphism (SNP)-based mapping approach, RNA-Seq and SNP array assisted super pooling analysis, was used for rapid mining of a candidate genomic region for stripe rust resistance gene Yr26 that has been widely used in wheat breeding programs in China. Large DNA and RNA super-pools were genotyped by Wheat SNP Array and sequenced by Illumina HiSeq, respectively. Hundreds of thousands of SNPs were identified and then filtered by multiple filtering criteria. Among selected SNPs, over 900 were found within an overlapping interval of less than 30 Mb as the Yr26 candidate genomic region in the centromeric region of chromosome arm 1BL. The 235 chromosome-specific SNPs were converted into KASP assays to validate the Yr26 interval in different genetic populations. Using a high-resolution mapping population (> 30,000 gametes), we confined Yr26 to a 0.003-cM interval. The Yr26 target region was anchored to the common wheat IWGSC RefSeq v1.0 and wild emmer WEWSeq v.1.0 sequences, from which 488 and 454 kb fragments were obtained. Several candidate genes were identified in the target genomic region, but there was no typical resistance gene in either genome region. Haplotype analysis identified specific SNPs linked to Yr26 and developed robust and breeder-friendly KASP markers. This integration strategy can be applied to accelerate generating many markers closely linked to target genes/QTL for a trait of interest in wheat and other polyploid species. [ABSTRACT FROM AUTHOR]

In situ zircon U–Pb ages and Hf isotopic data, whole‐rock major and trace element contents, and Sr–Nd isotopic compositions are reported for Permian intrusive rocks at Shaolanghe in Eastern Inner Mongolia in order to explore the magmatic origin and tectonic significance of these rocks for the evolution of the northern margin of the North China Craton. Three intrusive rocks, quartz diorite, Xishuiquan granite, and Xinglong granite, yield zircon U–Pb ages of 285.9 ± 3.1, 274.2 ± 2.9, and 260.0 ± 8.4 Ma, respectively. The quartz diorite and Xishuiquan granite belong to the high‐K calc‐alkaline series, enriched in large ion lithophile elements (e.g., Rb) and depleted in high field strength elements (e.g., Nb and Ti). They are defined as I‐type granites. The quartz diorite has initial 87Sr/86Sr ratios of 0.7049–0.7051, εNd(t) values of −10.0 to −11.4, and εHf(t) values of −15.2 to −9.9. The εHf(t) values of the Xishuiquan granite (−4.8 to 4.0) vary in discrete segments, whereas the εNd(t) values (−12.9 to −13.3) are consistent with those of the quartz diorites (−10.0 to −11.4). A magma mixing model is proposed for the formation of the quartz diorites of the Shaolanghe region, and the Xishuiquan granite was likely derived from partial melting of the Paleoproterozoic crust with involvement of mantle components. Geochemical analyses show that the tectonic setting of the northern margin of the North China Craton during the late Palaeozoic was an Andes‐type active continental margin associated with subduction of the Paleo‐Asian Ocean plate. [ABSTRACT FROM AUTHOR]

The newly discovered Xingwen porphyry Mo deposit is located in the most southern segment of the Xiaoxing'an Range–Zhangguangcai Range metallogenic belt (XZMB), NE China. The Mo deposit occurs with a granitic complex consisting of monzogranite, porphyritic granite and felsite porphyry. The Zircon U–Pb ages of monzogranite, porphyritic granite and felsite porphyry are 170.3 ± 2.1, 168.5 ± 2.5, and 166.7 ± 1.6 Ma, respectively. The inherited zircons from the monzogranite and porphyritic granite yield U–Pb ages of 239.8 ± 5.8 and 249.4 ± 6.2 Ma, respectively. These ages reveal that the Mo mineralization in the most southern segment of the XZMB took place in the Middle Jurassic, and is consistent with the epoch of the largest Daheishan Mo district in the XZMB. In contrast, Triassic ages of the inherited zircons are consistent with the ages of the Triassic magmatic activities along the E–W trending tectono‐magmatic belt in the northern margin of the North China Craton. The εHf(t) of the monzogranite, porphyritic granite and felsite porphyry change from −17.1 to +6.7 , −16.9 to +2.9, −5.94 to −0.90, respectively. The Hf isotopic compositions indicate that old crustal source, juvenile crustal source or depleted mantle contributed to their origin. When compared with the granite in Daheishan Mo district in XZMB, the εHf(t) probably indicates that the granitic complex in the margin of the Central Asia Orogenic Belt may have more old crustal materials than the granitic complex in the inner region of the Central Asia Orogenic Belt. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Static cold storage is accompanied with a partial safe ischemic interval for donor hearts. In this current study, a machine perfusion system was built to provide a better preservation for the donor heart and assessment for myocardial function. Chinese mini-swine (weight 30-35 kg, n = 16) were randomly divided into HTK, Celsior, and Heartbeat groups. All donor hearts were respectively preserved for 8 hours under static cold storage or machine perfusion. The perfusion solution is aimed to maintain its homeostasis based on monitoring the Heartbeat group. The ultrastructure of myocardium suggests better myocardial protection in the Heartbeat group compared with HTK or Celsior-preserved hearts. The myocardial and coronary artery structural and functional integrity was evaluated by immunofluorescence and Western blots in the Heartbeat. In the Heartbeat group, donor hearts maintained a high adenosine triphosphate level. Bcl-2 and Beclin-1 protein demonstrates high expression in the Celsior group. The Heartbeat system can be used to preserve donor hearts, and it could guarantee the myocardial and endothelial function of hearts during machine perfusion. Translating Heartbeat into clinical practice, it is such as to impact on donor heart preservation for cardiac transplantation. [ABSTRACT FROM AUTHOR]

The Songbei porphyry–skarn Mo deposit is situated in the eastern part of the Yanshan–Liaoning Mo metallogenic belt on the northern margin of the North China Craton. The deposit is temporally and spatially associated with alkali-feldspar granitic porphyry. We present LA-ICP-MS zircon U–Pb and molybdenite Re–Os dating, whole-rock geochemistry, and in situ zircon Lu–Hf isotopic data for the ore-bearing porphyry, in an attempt to constrain its petrogenesis and geodynamic setting. The LA-ICP-MS zircon U–Pb dating shows that the Songbei alkali-feldspar granitic porphyry was emplaced in the Early Jurassic (184 ± 2.0 Ma). Molybdenite Re–Os dating indicates that the associated Mo mineralization was contemporaneous (183.2 ± 3.0 Ma) with the igneous intrusion. The alkali-feldspar granitic porphyry belongs to the high-K calc-alkaline to shoshonitic series. The porphyry shows affinities with highly fractionated I-type granites: i.e., it is silica rich, with high contents of alkalis, pronounced enrichment of light REE relative to heavy REE, and has significant negative Ba, Sr, P, Ti, and Eu anomalies. Zircon extracted from the alkali-feldspar granitic porphyry has εHf(t) values of − 10.0 to − 6.9 and crustal model ages (T DM2 ) ranging from 1657 to 1860 Ma. It is suggest that the alkali-feldspar granitic porphyry formed by partial melting of the ancient lower crust of North China Craton followed by extensive fractionally crystallization. Both the geochemical signatures and the spatial − temporal distribution of mineralization during the Early − Middle Jurassic in eastern China suggest that the Songbei porphyry–skarn Mo deposit was formed in a continental margin setting associated with westward subduction of the paleo-Pacific plate in the Early Jurassic. [ABSTRACT FROM AUTHOR]

The Haigou lode deposit contains 40 t of gold at an average grade of 3.5 g/t, and is one of the largest deposits in the Jiapigou gold belt located along the eastern segment of the northern margin of the North China Craton. The deposit comprises 15 gold-bearing quartz veins hosted in a Carboniferous monzonite–monzogranite stock. Cretaceous dikes consisting of diorite, diabase, and granodiorite porphyries are well developed in the deposit. The diorite porphyry dikes (130.4 ± 6.3 Ma) occur together with gold-bearing quartz veins in NNE- and NE-striking faults. Gold-bearing quartz veins crosscut the diorite porphyry dikes, and the veins are in turn crosscut by E–W-striking 124.6 ± 2.2 Ma granodiorite porphyry dikes. The mineralization mainly occurs as auriferous quartz veins with minor amounts of sulfide minerals, including pyrite, galena, chalcopyrite, and molybdenite. Gold occurs as either native gold or calaverite. Common gangue minerals in the deposit include quartz, sericite, and calcite. The deposit is characterized by various types of hydrothermal alteration, including silicification, sericitization, chloritization, potassic alteration, and carbonatization. Three stages of hydrothermal activity have been recognized in the deposit: (1) a barren quartz stage; (2) a polymetallic sulfide (gold) stage; (3) a calcite stage. Fluid inclusions in hydrothermal pyrites have 3 He/ 4 He ratios of 0.3 to 3.3 Ra and 40 Ar/ 36 Ar ratios of 351 to 1353, indicating mixing of fluids of mantle and crustal origin. Hydrothermal quartz yielded δ 18 O values of −1.3‰ to +7.2‰ and δD values of fluid inclusions in the quartz vary between −80‰ and −104‰. These stable isotope data also suggest mixing of magmatic and meteoric fluids. Noble gas and stable isotopic data suggest that the ore fluids have a predominant mantle source with a significant crustal component. Based on the spatial association of gold-bearing quartz veins with early Cretaceous intrusions, and the H–O–He–Ar isotopic data from the deposit and intrusions, we propose that gold mineralization in the Haigou deposit was formed in an extensional setting and was related to the early Cretaceous, mantle-derived intrusions. [ABSTRACT FROM AUTHOR]

Fracture penetration or deflection may occur when the hydraulic fracture approaches weak interface in multi-layered formation. However, the intrinsic mechanism of fracture propagation pattern remains unclear. A model was presented to investigate hydraulic fracture propagation in multi-layered formation via the phase field method. The interface is explicitly represented by a weak thin layer. Fluid flow in the fractured media was modeled by using the indicator function of phase field. The iterative algorithm was described and validated against the benchmark cases. Simulation results show that the evolution of injection pressure is more complex when the fracture deflects than that when the fracture penetrates the interface. The fracture is prone to penetrate the softer layer the perforated layer while deflects to the interface if the adjacent layer is stiffer. Decreasing the modulus ratio of interface to layers promotes the fracture deflecting to the interface, while increasing the stress ratio contributes to the fracture penetrating the interface. The stacking mode of layers greatly affects the fracture propagation morphology in three or more layered formations. Rock heterogeneity doesn't alter the fracture propagation pattern as a whole, but it affects the local fracture morphology. The results provide a cloud chart of the relationship between fracture propagation pattern and controlling factors for the potential of field application. [ABSTRACT FROM AUTHOR]

The Jinchang gold deposit (more than 40 tons of gold) is located in the easternmost portion of the Central Asian Orogenic Belt. The gold mineralization types include mainly breccia, quartz vein and alteration rock types. Geological and geochemical characteristics suggest that the Jinchang gold deposit formed by the superposition of epithermal gold deposits and porphyry gold deposits. In this study, the helium and argon isotopic compositions of fluid inclusions in pyrites from the different ores are analyzed. The results show that 3He/4He ratios of fluid inclusions in pyrites range from 0.13 to 2.42 Ra, 40Ar/36Ar ratios are within 308.9-336.7, indicating that the ore-forming fluids of the Jinchang gold deposit were a mixture of crustal-derived fluids and partial mantle-derived fluids, and were contaminated by circum-flow meteoric water. From the early to the late mineralization stages, Jinchang gold deposit had a fluid evolution trend from more mantle fluid in the central area to crustal fluid in the outer area. Jinchang gold deposit is the result of superimposition of mineralization of magmatic fluids at different phases and nature. [ABSTRACT FROM AUTHOR]

Compared with the Mesozoic W–Sn–Cu–Au (Pb–Zn–Ag) mineralization in the South China Mo Province (SCMP), detailed studies on Mo deposits, especially Cretaceous Mo deposits are rare due to limited exposures. The Sanzhishu porphyry Mo deposit, located in the SCMP, is characterized by disseminated and veinlet-type molybdenite–quartz veins within monzogranite. Zircon SIMS U–Pb analysis of the monzogranite yields a concordia age of 112.3 Ma, indicating that the emplacement of the Sanzhishu monzogranite was in the Early Cretaceous. Six molybdenite samples yield Re–Os ages between 111 and 112 Ma, with an isochron age of 111 ± 6.4 Ma, which is consistent with the zircon age of the ore-bearing monzogranite. A new compilation of reliable Re–Os isotope age data indicate that Cretaceous Mo mineralization in the SCMP, occurred during two major episodes at 130–145 Ma and 90–120 Ma, with most deposits forming in the later episode. During the Cretaceous, a back-arc extensional setting in SE China is evidenced by the occurrence of numerous high-F Mo deposits, widespread A-type granites and the development of pull-apart basins. The increasing trend in Re contents of molybdenite from the early Mo mineralization period to the late Mo mineralization period in the SCMP indicates that the area experienced stronger crust–mantle interaction in the later mineralization episode. Based on geological evidence, we propose that the early episode of Mo mineralization formed in a tectonic setting associated with a metamorphosed subducted slab that experienced an increase in density and an increase in the gravitational pull on the slab itself, which induced rollback of the subducting Paleo-Pacific slab. The late episode of Mo mineralization developed in an extensional tectonic setting caused by the continued rollback and the eventual slab break-off. [ABSTRACT FROM AUTHOR]

The Buziwannan gold-polymetallic deposit is located in Northwest China's West Kunlun Orogen Belt (WKOB). There are two metallogenic stages that have been identified: skarn and hydrothermal. In this research study, in situ mineral geochemistry and sulfur–lead isotopes are used to precisely constrain the genesis and ore-forming process. Pyrite is the most dominant sulfide, and four types have been identified. Py0 is a sedimentary euhedral crystal; Py1 is a subhedral grain occurring in skarn ores, and coexists with Po1, Apy1, Ccp1 and Gn1; Py2, which coexists with Apy2, Po2 and Ccp2, is a subhedral to irregular crystal; and Py3 is a colloform crystal. Gn2 is the most recent sulfide. Magnetite and Ccp1 LA–ICMPS analyses indicate a skarn origin. Py0 and Py1 have the highest Co/Ni ratios and Ni contents, respectively, and Au has positive correlations with Pb, Ag and As, according to the trace element compositions of pyrite (LA–ICPMS). With the exception of four spots, most pyrites have Au (0.01–30.23 ppm) and As (1.47–15,709 ppm) concentrations below the Au saturation line, indicating that the majority of gold is present as lattice bound Au+. Py3 has clearly higher Sb contents indicating that Sb-rich fluids were added. The δ34S values of sulfides show that the sedimentary Py0 and skarn sulfides have the highest and lowest δ34S values of +13.30 to +14.67 ‰ and +4.48 to +7.77 ‰, respectively, and other sulfides possess δ34S values that fall between the two members, indicating a mixed source of magmatic and sedimentary. The lead isotope values also indicate that the sulfides from the hydrothermal stage have a mixed Pb source of magmatic and sedimentary. The skarn ores are spatially and genetically related to the Triassic granodiorite, indicating a Triassic age for ore formation. The Triassic magmatic intrusions hold the potential for future gold deposit exploration in the WKOB. • The Buziwannan is a skarn hydrothermal Au–polymetallic ore deposit formed in the Triassic. • Most of the gold is incorporated into the pyrite lattice as Au+. • Both magmatic and sedimentary (especially Sb-rich) fluid contributes the formation of Buziwannan. • The WKOB has the prospecting potential of intrusion related gold deposit. [ABSTRACT FROM AUTHOR]

The Wulaga gold deposit, located in Heilongjiang province, NE China, is a subvolcanic rock-hosted, low-sulfidation epithermal gold deposit, and has an Au reserve of about 84 tons. The gold mineralization occurs in a crypto-explosive breccia, and is spatially and temporally associated with an Early Cretaceous granodioritic porphyry. Three individual stages of mineralization have been identified in the Wulaga gold deposit: an early white quartz-euhedral vein stage, a fine-grained pyrite–marcasite–stibnite–chalcedony stage, and a late calcite–pyrite stage. The sulfur isotopic values of sulfide minerals vary in a wide range from − 4 to 4.9‰, but are concentrated in the range of − 3 to 0‰, implying that sulfur in the hydrothermal fluids was derived from magmatic volatiles. Lead isotopic results of the granodioritic porphyry ( 206 Pb/ 204 Pb = 18.341–18.395, 207 Pb/ 204 Pb = 15.507–15.523, 208 Pb/ 204 Pb = 38.174–38.251) and sulfide minerals ( 206 Pb/ 204 Pb = 18.172–18.378, 207 Pb/ 204 Pb = 15.536–15.600, 208 Pb/ 204 Pb = 38.172–38.339) are comparatively consistent and clustered together between the orogenic and upper mantle lines, indicating the lead in the ores is closely related to the parent magma of the granodioritic porphyry. The REE patterns of fluid inclusions trapped in sulfides are similar to those of the granodioritic porphyry, which confirms the magmatic origin of the REE in the hydrothermal fluids. The characteristics of S and Pb isotopes and REE suggest that the ore-forming materials of the Wulaga gold deposit are partly magmatic in origin, and related to a high-level hydrous granodioritic magma. [ABSTRACT FROM AUTHOR]

The Xilamulun Mo belt of Northeastern China, located in the southeastern segment of the Central Asia Orogenic Belt (CAOB), is composed of large deposits of porphyry Mo and quartz-vein-type Mo, which are related to Mesozoic granitoids. Previous studies led to the conclusion that all granitoids in the region formed during the Cretaceous and Triassic, but our new laser ablation inductively coupled plasma mass spectrometry U–Pb zircon dating of magmatic zircons from five samples of four mineralized plutons (Nailingou, Longtoushan, and Hashitu granites and Erbadi and Hashitu granite porphyries) reveals that these range in age from 143.8 ± 1.2 to 149.5 ± 1.0 Ma. These granites show post-collisional (A-type) geochemical characteristics (e.g. enrichment in total alkali, LILE, and LREE and depletion in Eu, Ba, P, and Nb). The Erbadi, Longtoushan, Hashitu, and Longtoushan granitoids exhibit moderately positive Hf isotopic compositions (εHf(t) = −0.3 to 10.2), indicating that granitic magmas may reflect mixtures of mantle melts and continental crust. These mineralized granites were all emplaced along a major fault over a time span of ~6 million years during the Late Jurassic. We conclude that igneous activity and mineralization resulted from the rollback of the subducted Palaeo-Pacific plate beneath Eurasia. Confirming that the Late Jurassic granitic intrusives are related to the Mo mineralization is useful for understanding the Mesozoic tectonic evolution of the Xilamulun Mo belt and also has significant implications for the regional exploration of ores. [ABSTRACT FROM PUBLISHER]

A portable laser-induced breakdown spectroscopy (LIBS) system based on a fiber laser was developed and employed to quantitatively analyze manganese (Mn), vanadium (V), and silicon (Si) elements in steels. After background removal, the coefficients of determination (R2 factors) of the calibration curves for Mn, V, and Si elements reached 0.997, 0.991 and 0.992, respectively, obvious improvements compared to those of the original spectra. The leave-one-out cross-validation (LOOCV) method was used to test the system. The root-mean-square error of cross-validation (RMSECV) for Mn (0.072–2.06 wt%), V (0.009–0.821 wt%), and Si (0.099–1.85 wt%) elements were 0.037, 0.041 and 0.079 wt%, respectively. The average relative errors (AREs) for Mn elements reached 7.6%. These results are comparable with those of the conventional LIBS which refers to utilizing the traditional flash-lamp-pumped laser as a laser source. However, compared to conventional LIBS, a fiber laser LIBS (FL-LIBS) is more compact, robust, and cost effective. The FL-LIBS, coupling a compact fiber laser and spectrometer, is a convenient approach to providing a portable solution for real-time and in situ detection in industry, especially in harsh environments. [ABSTRACT FROM AUTHOR]

The Xiaoxinancha Au-Cu deposit is located at the eastern segment of the Tianshan-Xingmeng orogenic belt in northeast China. The deposit includes porphyry Au-Cu orebodies, veined Au-Cu orebodies and veined Mo mineralizations. All of them occur within the diorite intrusion. The Late Permian diorite, Late Triassic granodiorite, Early Cretaceous granite and granite porphyry are developed in the ore area. The studies on geological features show that the porphyry Au-Cu mineralization is related to the Late Permian diorite intrusion. New geochronologic data for the Xiaoxinancha porphyry Au-Cu deposit yield Permian crystallization zircon U-Pb age of 257 ± 3 Ma for the diorite that hosts the Au-Cu mineralization. Six molybdenite samples from quartz + molybdenite veins imposed on the porphyry Au-Cu orebodies yield an isochron age of 110.3 ± 1.5 Ma. The ages of the molybdenites coeval to zircon ages of the granite within the errors suggest that the Mo mineralization was genetically related to the Early Cretaceous granite intrusion. The formation of the diorite and the related Au-Cu mineralization were caused by the partial melting of the subduction slab during the Late Palaeozoic palaeo-Asia Ocean tectonic stage. The Re contents and Re-Os isotopic data indicate that the crustal resource is dominated for the Mo mineralization during the Cretaceous extensional setting caused by the roll-back of the palaeo-Pacific plate. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

F, Mg and Ga co-doped ZnO (FMGZO) films are deposited on glass substrates at room temperature by magnetron sputtering using MgF 2 and ZnO:Ga targets. The effects of RF sputtering power applied to the MgF 2 target on structure, morphology, composition, electrical and optical properties of the films are investigated in detail. The experimental results show that all samples are polycrystalline films with hexagonal wurtzite structure and low surface roughness. The FMGZO film deposited at RF sputtering power of 15 W exhibits the highest figure of merit of 5.66 × 10−2 Ω−1 with the resistivity of 6.5 × 10−4 Ω cm, the carrier concentration of 4.12 × 1020 cm−3 and the Hall mobility of 23.38 cm2/V s, while the average optical transmittance is as high as 95.23% in the visible range. The photoelectric performance of the FMGZO film is significantly higher than that of previously reported co-doped ZnO films, which makes it suitable for various high-efficiency optoelectronic devices. [Display omitted] • F, Mg and Ga co-doped ZnO (FMGZO) films are deposited by magnetron sputtering. • Effects of sputtering power on properties of FMGZO films are investigated. • The FMGZO films have a typical hexagonal wurtzite structure and low roughness. • The optimal FMGZO film exhibits a low resistivity of 6.5 × 10−4 Ω cm. • The average visible transmittance of the best film exceeds 95%. [ABSTRACT FROM AUTHOR]