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Duobaoshan is the largest porphyry-related Cu-Mo-Au orefield in northeastern (NE) Asia, and hosts a number of large-medium porphyry Cu (PCDs), epithermal Au and Fe-Cu skarn deposits. Formation ages of these deposits, from the oldest (Ordovician) to youngest (Jurassic), have spanned across over 300 Ma. No similar orefields of such size and geological complexity are found in NE Asia, which reflects its metallogenic uniqueness in forming and preserving porphyry-related deposits. In this study, we explore the actual number and timing of magmatic/mineralization phases, their respective magma genesis, fertility, and regional tectonic connection, together with the preservation of PCDs. We present new data on the magmatic/mineralization ages (LA–ICP–MS zircon U-Pb, pyrite and molybdenite Re–Os dating), whole-rock geochemistry, and zircon trace element compositions on four representative deposits in the Duobaoshan orefield, i.e., Duobaoshan PCD, Tongshan PCD, Sankuanggou Fe-Cu skarn, and Zhengguang epithermal Au deposits, and compiled published ones from these and other mineral occurrences in the orefield. In terms of geochronology, we have newly summarized seven magmatic phases in the orefield: (1) Middle-Late Cambrian (506–491 Ma), (2) Early and Middle Ordovician (485–471 Ma and ∼462 Ma), (3) Late Ordovician (450–447 Ma), (4) Early Carboniferous and Late-Carboniferous to Early Permian (351–345 and 323–291 Ma), (5) Middle-Late Triassic (244–223 Ma), (6) Early-Middle and Late Jurassic (178–168 Ma and ∼150 Ma), and (7) Early Cretaceous (∼112 Ma). Three of these seven major magmatic phases were coeval with ore formation, including (1) Early Ordovician (485–473 Ma) porphyry-type Cu-Mo-(Au), (2) Early–Middle Triassic (246–229 Ma) porphyry-related epithermal Au-(Cu-Mo), and (3) Early Jurassic (177–173 Ma) Fe-Cu skarn mineralization. Some deposits in the orefield, notably Tongshan and Zhengguang, were likely formed by more than one mineralization events. In terms of geochemistry, ore-causative granitoids in the orefield exhibit adakite-like or adakite-normal arc transitional signatures, but those forming the porphyry-/epithermal-type Cu-Mo-Au mineralization are largely confined to the former. The varying but high Sr/Y, Sm/Yb and La/Yb ratios suggest that the ore-forming magmas were mainly crustal sourced and formed at different depths (clinopyroxene-/amphibole-/garnet-stability fields). The adakite-like suites may have formed by partial melting of the thickened lower crust at 35–40 km (for the Early Ordovician arc) and >40 km (for the Middle-Late Triassic arc) depths. The Early Jurassic Fe-Cu skarn ore-causative granitoids show an adakitic-normal arc transitional geochemical affinity. These granitoids were likely formed by partial melting of the juvenile lower crust (35‒40 km depth), and subsequently modified by assimilation and fractional crystallization (AFC) processes. In light of the geological, geochronological and geochemical information, we proposed the following tectonometallogenic model for the Duobaoshan orefield. The Ordovician Duobaoshan may have been in a continental arc setting during the subduction of the Paleo-Asian Ocean, and formed the porphyry-related deposits at Duobaoshan, Tongshan and Zhengguang. Subduction may have ceased in the latest Ordovician, and the regional tectonics passed into long subsidence and extension till the latest Carboniferous. This extensional tectonic regime and the Silurian terrestrial-shallow marine sedimentation had likely buried and preserved the Ordovician Duobaoshan magmatic-hydrothermal system. The south-dipping Mongol-Okhotsk Ocean subduction from north of the orefield had generated the Middle-Late Triassic continental arc magmatism and the associated Tongshan PCD and Zhengguang epithermal Au mineralization (which superimposed on the Ordovician PCD system). The Middle Jurassic closure of Mongol-Okhotsk Ocean in the northwestern Amuria block (Erguna terrane), and the accompanying Siberia-Amuria collision, may have placed the Paleo-Pacific subduction system in NE China (including the orefield) under compression, and formed the granodiorite-tonalite and Fe-Cu skarn deposits at Sankuanggou and Xiaoduobaoshan. From the Middle Jurassic, the consecutive accretion of Paleo-Pacific arc terranes (e.g., Sikhote-Alin and Nadanhada) onto the NE Asian continental margin may have gradually distant the Duobaoshan orefield from the subduction front, and consequently arc-type magmatism and the related mineralization faded. The minor Late Jurassic and Cretaceous unmineralized magmatism in the orefield may have triggered mainly by the far-field extension led by the post-collisional (Siberia-Amuria) gravitational collapse and/or Paleo-Pacific backarc-basin opening.

Most skarns are found near the pluton or in lithologies containing at least some limestone. However, recent research has shown that neither a pluton nor limestone is necessarily required to form a skarn deposit. The newly discovered Bagenheigeqier Pb–Zn skarn deposit is located in NE China. The skarn and Pb–Zn orebodies occur in volcanic lithologies of the Baiyin’gaolao Formation and are controlled by NE–SW-trending faults. The nearest pluton is a granite porphyry, at a distance of 20–250 m from the orebodies. Five paragenetic stages at Bagenheigeqier are recognized: (I) skarn; (II) oxide; (III) early sulphide; (IV) late sulphide; and (V) late quartz–calcite. The fluid inclusions from stages II to V homogenized at temperatures of 402–452, 360–408, 274–319 and 167–212°C, respectively. The hydrogen and oxygen isotope compositions (δ18OH2O, –12.4‰ to +9.3‰; δDH2O, –156.5‰ to –99.1‰) indicate that the ore-fluids were primarily of magmatic origin, with the proportion of meteoric water increasing during the progression of ore formation. Sulphur isotope values (δ34SVCDT, 1.4–5.5‰), lead isotope values (206Pb/204Pb, 18.184–18.717; 207Pb/204Pb, 15.520–15.875; 208Pb/204Pb, 37.991–38.379) and the initial 187Os/188Os ratios of the pyrite (0.307 ± 0.06) suggest that the ore metals were derived from the granite porphyry and Baiyin’gaolao Formation. Re–Os dating of pyrite intergrown with galena and sphalerite yielded a well-constrained isochron age of 151.2 ± 4.7 Ma, which is coeval with the laser ablation – inductively coupled plasma – mass spectrometry zircon U–Pb age of 154 ± 1 Ma for the granite porphyry. The deposit was therefore formed during Late Jurassic time.

We studied the fluid inclusions of the Jiguanshan Mo deposit in China, which is a large porphyry deposit located in the southern Xilamulun Metallogenic Belt. The irregular Mo ore body with various types of hydrothermal veinlets is hosted by Late Jurassic granite porphyry. Intense hydrothermal alterations in the deposit from the core to margin are silicification–potassium feldspar alteration, pyrite–quartz–sericite–fluorite alteration, and propylitic alteration. Based on the mineral assemblages and crosscutting relationships of ore veins, the ore-forming process were divided into three stages and two substages: quartz–pyrite veins (stage I) associated with potassic alteration; quartz–molybdenite–chalcopyrite–pyrite veins (substage II-1) and quartz–molybdenite–fluorite veins (substage II-2) associated with phyllic alteration; and fluorite–quartz–carbonate veins (stage III) with carbonation. Five major fluid inclusions (FIs) types were distinguished in the quartz associated with oxide and sulfide minerals, i.e. polyphase brine (Pb-type), opaque-bearing brine (Ob-type), solid halite (S-type), two-phase aqueous (A-type), and vapor (V-type) inclusions. The FIs of stage I were composed of liquid-rich S-, A-, and V-type FIs with homogenization temperatures and salinities of 490 to 511 °C and 8.9 to 56.0 wt% NaCl equiv., respectively. The FIs of substage II-1 are composed of Pb-, Ob-, S-, A-, and V-type FIs with homogenization temperatures and salinities of 352 to 460 °C and 3.7 to 46.1 wt% NaCl equiv, respectively. The FIs of substage II-2 are Ob-, S-, A-, and V-type FIs with homogenization temperatures and salinities of 234 to 309 °C and 3.7 to 39.2 wt% NaCl equiv, respectively. The FIs of stage III are A-type FIs with homogenization temperatures and salinities of 136 to 172 °C and 1.1 to 8.9 wt% NaCl equiv, respectively. Fluid boiling, which resulted in the precipitation of sulfides, occurred in stages I and II. The initial ore-forming fluids of the Jiguanshan deposit had high temperature, high salinity, and belonged to an F-rich NaCl ± KCl–H2O system. The fluids gradually evolved to low temperature, low salinity, and belonged to a NaCl–H2O system. Studies of the hydrogen and oxygen isotope compositions of quartz (δ18OH2O = − 7.3 to 6.3‰, δDH2O = − 104.3 to − 83.3‰) show that the ore-forming fluids gradually evolved from magmatic water to meteoric water.

To analyze the effect of triple antibiotic paste on root canal microorganisms in periapical periodontitis of different stages.Eighty-nine children with periapical periodontitis of deciduous teeth in Department of Stomatology, Children's Hospital of Nanjing Medical University from April 2017 to April 2020 were enrolled, and divided into two groups according to the clinical symptoms and root X-ray films, i.e., acute inflammation group and chronic inflammation group. Samples of infected root canals were collected for bacterial identification, isolation and purification. The detection of microorganisms in the infected root canal and the composition of anaerobic microorganisms were analyzed in both groups. Disk diffusion method was used to observe antimicrobial effects of triple antibiotic paste and calcium hydroxide against common anaerobic bacteria, and the sensitivity of different anaerobic bacteria to triple antibiotic paste. Statistical analysis was completed by SPSS 20.0 software package.The microorganisms in both groups were mainly anaerobic bacteria. The detection rates of aerobes and anaerobic bacteria in the infected root canals had no significant difference between the two groups (P0.05). The top five anaerobes detected in infected root canals were Peptostreptococcus, Bacteroidetes, Enterococcus faecalis, Porphyromonas gingivalis and Fusobacterium nucleatum. The detection rates of Porphyromonas gingivalis, Fusobacterium nucleatum and Bacteroidetes in infected root canal of acute inflammation group were significantly higher than those of chronic inflammation group, and the detection rate of Enterococcus faecalis was significantly lower than that of chronic inflammation group(P0.05). The bacteriostatic circle diameter of triple antibiotic paste against Peptostreptococcus, Bacteroidetes, Enterococcus faecalis, Porphyromonas gingivalis and Fusobacterium nucleatum was significantly larger than that of calcium hydroxide(P0.05). The sensitivity of different anaerobic bacteria to triple antibiotic paste was highest in Enterococcus faecalis, followed by Peptostreptococcus, Porphyromonas gingivalis, Fusobacterium nucleatum, and Bacteroidetes(P0.05).Triple antibiotic paste has good antimicrobial effect on the common bacteria in the infected root canal of acute and chronic periapical periodontitis.

Whether multiple mineralization styles in porphyry deposits are the result of one or multiple pulses of magmatism is unknown. In this paper, we present new age and geochemical data on the Jinchang porphyry gold-copper (Au-Cu) deposit, an important deposit in NE China and in the eastern Central Asian Orogenic Belt (CAOB). Field geological study suggests that both the mineralization and ore-causative magmatism at Jinchang are multiphase. LA-ICP-MS zircon U-Pb dating of the monzogranite ore host yielded 197 ± 1 Ma, which is considerably older than the ore-causative monzonite (115 ± 3 Ma) and granodiorite (107 ± 2 Ma). Molybdenite Re–Os dating on the breccia pipe-hosted Au-Cu ores yielded a well-defined isochron age of 114 ± 3 Ma, coeval to the monzonite emplacement. The Au-Cu mineralization was followed by another phase of crypto-explosive breccia pipe-hosted, disseminated/vein-type Au mineralization. This Au-only mineralization phase was auriferous pyrite Re–Os dated to be 103–101 Ma, coeval to the granodiorite emplacement. Geochemically, the monzonite and granodiorite are enriched in LILEs and LREEs, but depleted in HFSEs and HREEs. The ore-causative rocks are I-type and display continental arc geochemical affinities. We suggest that the monzonite and granodiorite were generated in an intracontinental extensional setting, probably caused by the Early Cretaceous subduction roll-back of the Paleo-Pacific Plate.

The Changlingzi Pb–Zn deposit is located in the southern Great Xing’an Range metallogenic belt of Northeast China. This deposit experienced two types of mineralization including skarn (ore block I) and hydrothermal vein (ore block II), and their orebodies are hosted mainly in the Lower Permian Zhesi Formation. The hydrothermal mineralization is classified into two metallogenic periods: skarn (stage 1) and sulfide (stages 2, 3, and 4). The skarn period affected only the ore block I, whereas the sulfide period similarly affected the two ore blocks. Fluid inclusion studies indicate that the ore-forming fluids during the early stage were medium- to high-temperature, high-salinity heterogeneous NaCl–H2O fluids, and that they eventually evolved to low-temperature, low-salinity homogeneous NaCl–H2O fluids by late stage. Studies of the hydrogen and oxygen isotope compositions (δ18OH2O = −13.85‰ to 3.95‰, δDH2O = −132.8‰ to −102.7‰) show that the ore-forming fluids gradually evolved from magmatic water to meteoric water. Sulfur and lead date suggest that the ore-forming materials were probably derived from deep magma and the Permian strata. Although our data show that ore blocks I and II, in terms of genesis, were skarn- and medium- to low-temperature hydrothermal vein-types, respectively, the ore-forming fluids of both ore blocks were the same period, and the differences in mineralization type can be related to the wall rocks.

The Bianbianshan Cu-polymetallic deposit is located in the Xilamulun Cu-Mo belt of Inner Mongolia, NE China, and occurs within Late Jurassic andesite, rhyolite and tuff. Cu mineralization is observed in various types of hydrothermal disseminated veins exhibiting siliciification, sericitization and chloritization. The ore-forming process occurred in four stages: (1) chalcopyrite-pyrite-quartz, (2) pyrite-chalcopyrite-quartz-vein, (3) sphalerite-galena-quartz-vein, (4) and quartz-calcite-vein. Three types of fluid inclusions were identified in the deposit, including C-type (CO2-NaCl-H2O) as well as V- and L-type (NaCl-H2O) inclusions, where only L-type inclusions are observed in the fourth stage. Homogenization temperature of fluid inclusions in the four stages are 325–365 °C, 282–335 °C, 268–312 °C, and 195–259 °C, respectively, all of which exhibit salinities lower than ∼ 13 wt% NaCl equiv. Trapping pressure estimated from C, V- and L-fluid inclusions are between 550 and 900 bars, corresponding to minimum depths of 2.5–3.7 km. Hydrogen and oxygen isotopic compositions of quartz from different stages (δD = −109.7 ~ –107.6‰, δ18O = 7.6–9.6‰, V-SMOW) suggest that the mineralizing fluid gradually evolved from a magmatic to a meteoric origin. Sulfur (δ34SV-CDT = −0.7 to 0.4‰) and lead isotopes (208Pb/204Pb = 37.746–38.137‰; 208Pb/204Pb = 15.52–15.56%; 206Pb/204Pb = 17.75–18.36%) indicate that ore-forming materials were derived from mantle with minor additional participation of crustal reservoirs. Our data suggests the ore-forming fluids of the Bianbianshan Cu-polymetallic deposit are attributed to a moderate temperature, moderate-low salinity, and moderate density system, where decreases in pressure, phase separation and local mixing with meteoric water drove precipitation of metals.

The Duobaoshan orefield is located in the eastern part of the Central Asian Orogenic Belt (CAOB) and underwent multiphase magmatism and mineralization. The Zhengguang deposit in the orefield is characterized by porphyry copper mineralization and intermediate-sulfidation (IS) epithermal gold mineralization. The porphyry-type veinlet-disseminated sulfide mineralization (~480 Ma) is hosted in granodiorite/tonalite porphyries and hydrothermal breccias, and is associated with widespread potassic (K-feldspar and biotite) alteration. Three porphyry-type mineralization stages have been identified: (I-1) quartz + medium-fine grained pyrite, (I-2) quartz + pyrite + chalcopyrite, and (I-3) quartz + calcite + minor pyrite. The IS epithermal vein/veinlet-disseminated mineralization occurs in andesite porphyry and fractures of the Duobaoshan Formation volcanic rocks, and is associated with extensive silicic, sericitic, and pyrite-sericitic-silicic alterations and minor propylitic alteration. Three IS epithermal-type mineralization stages are identified: (II-1) quartz + coarse-grained pyrite, (II-2) quartz + polymetallic sulfides, and (II-3) quartz + calcite + barren sulfides. Five stage II-2 pyrite samples yielded a Re-Os isochron age of 246.0 ± 6.4 Ma (MSWD = 0.85), suggesting a Triassic Au mineralization event after the Ordovician Cu mineralization. Stage I-1 fluid inclusions (FIs) are predominantly of VL- and LV-type and minor SL-type, with homogenization temperatures (Th) of 283–359 ℃ and salinities of 0.3–35.1 wt%. Stage I-2 is characteristically composed of VL- and LV-type inclusions with Th of 193–296 ℃ and salinities of 0.8–14.2 wt%. Only VL-type inclusions occur in stage I-3, II-1, II-2, and II-3 with Th of 149–216 ℃, 213–285 ℃, 169–236 ℃, and 125–176 ℃, and salinities of 2.4–7.9 wt%, 6.5–12.2 wt%, 3.4–8.8 wt%, and 2.1–6.3 wt%, respectively. H-O isotopic compositions for the mineralization (Ordovician: δ18OH2O = -9.9 to −0.5‰, δD = -86 to −75.6‰; Triassic: δ18OH2O = -8.4 to −2‰, δD = −134.1 to −88.5‰) indicate two different evolving fluid systems, both with an initial magmatic source and a later meteoric water incursion. Sulfur and lead isotope (Ordovician: δ34S (−3.1 to −0.7‰), 206Pb/204Pb (17.570–17.613), 207Pb/204Pb (15.427–15.441), 208Pb/204Pb (37.258–37.294); Triassic: δ34S (-5.4 to −2.5‰), 206Pb/204Pb (17.627–17.965), 207Pb/204Pb (15.466–15.534), 208Pb/204Pb (37.468–37.703)) values suggest a dominantly magmatic and a mixed magmatic-sedimentary source for the Ordovician and Triassic mineralization, respectively.

The Hua'naote Ag-Pb-Zn deposit (Inner Mongolia, northern China) is a hydrothermal vein-type deposit in the Erlianhot-Dongwuqi Metallogenic Belt (EDMB), which is situated in the eastern Central Asian Orogenic Belt (CAOB). Mineralization occurs in the contact between monzogranite and the Devonian Angeer Yinwula Formation (Fm.) silty slate, and is also closely related to syenogranite. The mineralization can be divided into three stages: (I) arsenopyrite + pyrite + quartz, (II) pyrite + galena + sphalerite + chalcopyrite + quartz, and (III) galena + sphalerite + calcite + quartz. Fluid inclusions (FIs) from Hua'naote are liquid-rich (L-type), vapor-rich (V-type), CH4 + CO2 (C1-type), CO2-bearing (C2-type), and daughter-mineral-bearing three-phase (S-type). Laser Raman spectral analysis shows that the gas phase in Stage I and II C2-type FIs is mainly composed of H2O, CO2, N2 and CH4, while that in Stage III FIs contains predominantly H2O. Stage I FIs are of L-, V-, C1-, C2- and S-types. These FIs homogenized mainly at 300–380 °C, and their salinities are bimodal (1.7–8.4 wt% and 35.2–45.8 wt% NaCl eqv.). Our results suggest that Stage I fluids belong to a NaCl–H2O–CO2 ± CH4 system characterized by medium-to-high temperature and salinity. Stage II FIs are of L-, V- and C2-types, with homogenization temperatures and salinities of 180.4–302.8 °C and 2.23–5.70 wt% NaCl eqv., respectively. Stage II fluids belong to a NaCl–H2O–CO2 system featured by medium-to-low temperature and low salinity. Stage III FIs contain only L-type, with homogenization temperatures and salinities of 125.5–244.6 °C and 2.56–4.94 wt% NaCl eqv., respectively. Stage III fluids belong to a NaCl-H2O system characterized by low temperature and salinity. The δ18Ofluid and δDfluid values of quartz and calcite are of −4.70 to 5.50‰ and − 144.8 to −121.8‰, respectively, indicating that the Hua'naote early-ore fluids were mainly derived from the magma with minor meteoric water input. The Hua'naote sulfides have δ34SCDT = −0.3 to 8.2‰ (mainly 0–2‰ and 5–8‰), and 206Pb/204Pb = 18.304–18.483, 207Pb/204Pb = 15.552–15.683 and 208Pb/204Pb = 38.104–38.350. The sulfur and lead isotope evidence suggests that the ore metals were sourced primarily from deep-seated magma with minor upper crustal input. We suggest that the Hua'naote Ag-Pb-Zn deposit is best classified as intrusion-related, fractures-controlled medium-temperature hydrothermal vein-type deposit.

The Middle Triassic Laojiagou porphyry Mo deposit is located in the Xilamulun metallogenic belt, along the northern margin of the North China Craton (NCC). Molybdenum mineralization is associated with a monzogranite porphyry and occurs primarily in quartz veins and veinlets hosted in wall rocks affected by potassic, silicic, sericitic, and propylitic alteration. The ore-forming process is divided into three stages, characterized by veinlets comprising molybdenite + pyrite + quartz (stage I), pyrite + chalcopyrite + molybdenite + quartz (stage II), and pyrite + quartz (sulfide-poor) (stage III). We identify three fluid inclusion types in quartz grains: carbonic (C-type), liquid-rich two-phase (L-type), and rare vapor-rich two-phase (V-type) inclusions. Microthermometric results indicate that an initial high-temperature (> 350 °C) and low-salinity (

The Angeer Yinwula Pb–Zn deposit of Inner Mongolia, China, is located in the Erlianhot–Dongwuqi metallogenic belt, which is considered to be the eastern part of the Central Asian Orogenic Belt. We used the ore geology, fluid inclusion, isotopes, and zircon U–Pb geochronology to elucidate the genesis and tectonic setting of the deposit. The deposit belongs to the moderate-temperature hydrothermal-vein type, and most of the ore bodies occurred in the quartz diorite intrusions and silty slate country rocks of the Devonian Angeer Yinwula Group. Fluid inclusion petrography and microthermometry results show that the inclusions that developed in the different mineralization stages changed from the LV type (vapor-rich two-phase) + S type (daughter-mineral-bearing three-phase) + VL type (liquid-rich two-phase) to the VL type + LV type and eventually evolved into the VL type, and the ore-forming fluids changed from a moderate-temperature and moderate- to high-salinity, boiling fluid system to a low-temperature and low-salinity H2O–NaCl system. The isotope (C, H, O, S) characteristics suggest that the ore-forming fluids were derived from a magmatic source, and the lead was derived from a deep-seated mantle-derived magma and also included some crustal material. The LA–ICP–MS zircon U–Pb age of the quartz diorite is 152.0 ± 1.5 Ma, which is the best estimate for the age of mineralization of the deposit. Overall, we suggest that the deposit formed in a Late Jurassic Paleo-Pacific Plate subduction setting, although this hypothesis needs to be further tested by conducting computational simulations in the field of emerging computational geosciences.

Herein, zircon U-Pb geochronology, Lu-Hf isotopes, and whole-rock major and trace element geochemistry are presented for two Palaeoproterozoic granitic rocks in Qingchengzi district, northeastern Jiao-Liao-Ji Belt (JLJB). These new geochronological and geochemical data provide reference clues for exploring the petrogenesis and tectonic setting of Paleoproterozoic magmatic rocks in the Qingchengzi district, which further constrain the tectonic nature of the JLJB. Our zircon U-Pb dating denotes that the Paleoproterozoic magmatic events in the Qingchengzi district were emplaced at ~2163 Ma and ~1854 Ma, represented by granite porphyry and biotite granite, respectively. Geochemically, these Palaeoproterozoic rocks are characterized by high Sr (760&ndash, 842 ppm), SiO2 (69.72&ndash, 70.89 wt.%), and Al2O3 (15.53&ndash, 16.78 wt.%) contents, low Y (2.1&ndash, 9.0 ppm) and Yb (0.25&ndash, 0.80 ppm) contents, which indicate an adakite affinity. Combined with Hf isotopic composition (&epsilon, Hf(t) = &minus, 1.5~+4.8, TDM2 = 3109~2560 Ma), we believe that the Paleoproterozoic adakitic magma originated from partial melting of the thickened lower crust material in the Meso-Neoarchean. Moreover, these rocks are enriched in light rare earth elements and large ion lithophilic elements (e.g., K, Rb, and Cs), and depleted in heavy rare earth elements and high field strength elements (e.g., Nb and Ta). These features are similar to magmatic rocks formed in an arc environment (either island arc or active continental margin) and are not consistent with an intraplate/intracontinental environment. According to this study and previous research results, we conclude that the arc&ndash, continent collision model is conducive to the Paleoproterozoic tectonic attribute of the JLJB, and the oceanic crust subduction between the Namgrim and Longgang blocks may have induced the widespread occurrence of magmatic events in the region.

The Qingchengzi Au–Ag orefield is a key Au province in the North China Craton. The fault-controlled orebodies are hosted in the Paleoproterozoic meta-sedimentary rocks of the Dashiqiao and Gaixian Formations. We present new bulk-ore REE, fluid inclusion (FI) microthermometric and mineral H–O–S–Pb isotopic data of these Au–Ag deposits, and discuss their ore fluid/material source and metallogenesis. Our FI microthermometric data indicate that the ore fluids are of medium temperatures (260–310 °C), low salinity (≤10 wt% NaCl eq.), and belonged to a H2O–CO2–NaCl system. Hydrogen (δD = –6.5 to 9.1‰) and oxygen (δ18O = –139.4 to –90.1‰) isotopes of the hydrothermal quartz indicate that the early-stage ore-forming fluids were mainly magmatic sourced. The δ34S values (–12.5 to 18.7‰) of the ore sulfides overlap with the Paleoproterozoic ore host (δ34S = –0.5 to 13.2‰) and the Late Triassic granites (δ34S = 5.6–7.6‰). Lead isotope compositions of the ore sulfides (206Pb/204Pb = 17.269–18.334; 207Pb/204Pb = 15.335–15.883; 208Pb/204Pb = 37.254–38.784) also support a metallogenic link with the granites and wall-rocks. Therefore, we suggest that the Qingchengzi Au–Ag deposits are best classified as magmatic-related medium-temperature hydrothermal lode type, albeit spatial correlations with magmatic intrusions are not ubiquitous. Closer to the hydrothermal centers, the higher-temperature, magmatic-dominated fluids were responsible to generate the Au(-Ag) mineralization, whereas the more distal, lower-temperature magmatic-meteoric-mixed fluids may have formed the Ag and Pb–Zn mineralization. The ore-forming fluids and materials were likely sourced mainly from the Triassic granitoids, although significant contributions of ore metals and sulfur from the Au-/Ag-rich Dashiqiao and Gaixian Formations should not be neglected. Considering the regional tectonic setting, the Late Triassic Qingchengzi Au–Ag polymetallic mineralization may have occurred during the post-collisional extension after the Yangtze-North China continent–continent collision.

Simvastatin, an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, is been used in the clinic due to its pleiotropic effects, such as breast cancer, prostate cancer, pancreatic cancer. Simvastatin has recently been demonstrated to serve a potential role in the prophylaxis and therapeutics of a number of human cancers. The majority of reports concerning simvastatin treatment in the majority of human cancers have demonstrated that survivin is significantly decreased as a result and has been implicated in tumorigenesis. However, only a limited number of studies have investigated the use of simvastatin for the treatment of salivary gland adenoid cystic carcinoma (SACC). Therefore, this agent is a candidate for further investigation. The aim of the present study was to investigate the effects of simvastatin on the proliferation, invasion and apoptosis of the human salivary adenoid cystic carcinoma cell line, SACC-83, as well as survivin expression in the cells. The Cell Counting kit-8 assay results revealed that simvastatin inhibited the proliferation of SACC-83 cells in a dose-dependent (10 to 50 µM) and time-dependent (24 to 48 h) manner when compared with the untreated cells. Flow cytometry analysis indicated that simvastatin increased the percentage of cells in early and late apoptosis. Invasion assays revealed that simvastatin treatment inhibited the invasiveness of SACC-83 cells in a dose-dependent manner. In addition, simvastatin downregulated survivin expression in SACC-83 cells. In conclusion, simvastatin significantly inhibited the proliferation and invasion of SACC-83 cells, induced apoptosis, and reduced the expression of survivin, which suggests that simvastatin may be a novel target for SACC therapy.

The Qingchengzi Pb–Zn deposit is located in the northeastern Jiao–Liao–Ji Belt (JLJB), North China Craton (NCC). Field observation and age dating indicate that the deposit was formed from Paleoproterozoic sedimentary exhalative (SEDEX) stratiform mineralization overprinted by Late Triassic hydrothermal vein-type mineralization. Five types of fluid inclusions (FIs) are identified in the quartz grains, based on petrography and laser Raman spectroscopy: liquid-rich two-phase (type 1), vapor-rich two-phase (type 2), CO2-bearing (types 3a and 3b), and CO2-pure (type 4). Quartz from the SEDEX stratiform ores contains only type 1 FIs, and hydrogen-oxygen isotopic compositions indicate that the ore-forming fluids were magmatic water-derived. The ore-forming fluids were likely of medium-temperatures and low-salinity, and belonged to a NaCl–H2O hydrothermal system. Quartz from the vein-types contains all five types of FIs, and the ore-forming fluids may have belonged to a medium-temperature, low-salinity NaCl–H2O–CO2 hydrothermal system. Hydrogen-oxygen isotopes indicate that the vein-type ore-forming fluids were derived from magmatic-meteoric mixed source. Rare-earth element (REE) and sulfur-lead isotopic compositions indicate that ore-forming materials of the SEDEX stratiform mineralization were derived from the wall-rocks and magma, wheres those of the vein-type mineralization were derived from Late Triassic granitic magma, wall-rocks, and the Paleoproterozoic SEDEX ores. Based on field geological and geochronological data, we propose the following regional metallogenic model: (1) SEDEX mineralization occurred during the Paleoproterozoic post-collisional extension in the JLJB; (2) vein-type mineralization was generated by the north-dipping subduction of the Yangtze Craton beneath the NCC, which led to continent-continent collision and slab break-off in the Late Triassic.

The Jinchang gold deposit is located in the eastern Yanji&ndash, Dongning Metallogenic Belt in Northeast China. The orebodies of the deposit are hosted within granite, diorite, and granodiorite, and are associated with gold-mineralized breccia pipes, disseminated gold in ores, and fault-controlled gold-bearing veins. Three paragenetic stages were identified: (1) early quartz&ndash, pyrite&ndash, arsenopyrite (stage 1), (2) quartz&ndash, chalcopyrite (stage 2), and (3) late quartz&ndash, galena&ndash, sphalerite (stage 3). Gold is hosted predominantly within pyrite. Pyrite separated from quartz&ndash, arsenopyrite cement within the breccia-hosted ores (Py1) yield a Re&ndash, Os isochron age of 102.9 &plusmn, 2.7 Ma (MSWD = 0.17). Pyrite crystals from the quartz&ndash, chalcopyrite veinlets (Py2) yield a Re&ndash, Os isochron age of 102.0 &plusmn, 3.4 Ma (MSWD = 0.2). Pyrite separated from quartz&ndash, sphalerite veins (Py3) yield a Re&ndash, Os isochron age of 100.9 &plusmn, 3.1 Ma (MSWD = 0.019). Re&ndash, Os isotopic analyses of the three types of auriferous pyrite suggest that gold mineralization in the Jinchang Deposit occurred at 105.6&ndash, 97.8 Ma (includes uncertainty). The initial 187Os/188Os values of the pyrites range between 0.04 and 0.60, suggesting that Os in the pyrite crystals was derived from both crust and mantle sources.