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The glass compound eye bead is the exquisite embodiment of the glassmaking technology of ancient craftsmen, and is an example of the cultural exchange between China and the West during the Warring States Period. This study takes two dots and mesh beads with seriously weathered surfaces excavated from Hejia village, Zhouling as the research object. Micromorphology, X-ray fluorescence spectroscopy (XRF), microscopic laser Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) were respectively used to determine the chemical elements, valence states and compositions of the glass matrix and its weathering products. In this study, the valence state analysis of group-d elements is used to reveal the electron transition mode and explain the colour formation reason of blue-black glass matrix. In terms of weathering products, in addition to the identification of common cerusite [PbCO3] and barite [BaSO4], the study also found the blue weathering product alforsite [Ba5(PO4)3Cl] for the first time. The study also makes reasonable assumptions about the reasons for their appearance. The X-ray photoelectron spectroscopy (XPS) used in this study has positive significance for the study of the formation mechanism of glass colour. The scientific and technological analysis data of these two glass beads provide basic data for the related research of the lead-barium glass system produced in China, and also provide a certain scientific basis for the related protection research. [ABSTRACT FROM AUTHOR]

In order to realize rapid and accurate evaluation of drinking water quality, a small-scale water quality detection instrument is designed in this paper that can detect two representative water quality parameters: the permanganate index and total dissolved solids (TDS). The permanganate index measured by the laser spectroscopy method can achieve the approximate value of the organic matter in water, and the TDS measured by the conductivity method can obtain the approximate value of the inorganic matter in water. In addition, to facilitate the popularization of civilian applications, the evaluation method of water quality based on the percent-scores proposed by us is presented in this paper. The water quality results can be displayed on the instrument screen. In the experiment, we measured the water quality parameters of the tap water as well as those after the primary and secondary filtration in Weihai City, Shandong Province, China. The testing results show that the instrument can quickly detect dissolved inorganic and organic matter, and intuitively display the water quality evaluation score on the screen. The instrument designed in this paper has the advantages of high sensitivity, high integration, and small volume, which lays the foundation for the popularity of the detection instrument. [ABSTRACT FROM AUTHOR]

Recent discoveries of oil and gas have principally been located in the central part of the Ordos Basin, which is a petroliferous basin with the largest discovered reserves and annual production of tight sandstone gas in China. For tight sandstone gas reservoirs in the transition zone of the basin margin, the process of natural gas accumulation has remained relatively vaguely understood, because of the transitional accumulation of geological conditions such as structure, sedimentation, and preservation. In this study, thin-section identification and scanning electron microscopic observations of the reservoir core, measurement of the physical properties of the reservoir, microscopic petrography research and measurement of the homogenization temperature of fluid inclusions, digital simulations, and laser Raman spectroscopy analysis were combined to analyze the process of natural gas accumulation of the Permian Lower Shihezi Formation in Duguijiahan block, Hangjinqi area, northern Ordos Basin. The results showed that the Lower Shihezi Formation reservoir in the Duguijiahan block began gas charging in the southern part as early as the Early Cretaceous (130–128 Ma), and then gradually charged in the northern part. Three stages were identified in the digital simulations of gas charging, i.e., the breakthrough, rapid, and fully saturated stages. The initial porosity of the Lower Shihezi Formation reservoir ranged between 28% and 40%. Later, because of strong compaction and interstitial filling during burial, the sandstone porosity decreased rapidly, and densification (porosity < 10%) occurred in the mid–late Jurassic. This late tectonic uplift caused a continuous reduction in ground temperature, and diagenesis had a weak effect on pore transformation. The present porosity of the Lower Shihezi Formation reservoir basically inherited its characteristics in the late Early Cretaceous. The current average porosity of the reservoir is 8.58%, and the average permeability is 0.88 mD, and it can thus be characterized as a tight reservoir. The gas accumulation process of the Lower Shihezi Formation has three stages: (1) the depositional stage (C–P), corresponding to the depositional stage of the source-reservoir-cap combination in gas reservoir; (2) the natural gas accumulation stage (T–K1), corresponding to the period of rapid source rock maturation and natural gas charging step-by-step; and (3) the gas reservoir adjustment stage (K2–present), corresponding to the period of uplift and natural gas charging in the early stage that gradually migrated and accumulated northward along the fracture zone. Finally, the gas accumulation model in the transition zone at the margin of basin was established. [ABSTRACT FROM AUTHOR]

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Accurate estimates of the thermal maturity of organic matter are important in studies of shale oil and gas, as these data are directly related to the genesis type of shale gas, adsorption capacity of shale and formation of organic pores in organic-rich shale. Longmaxi shale is a major shale gas exploration target in South China and a typical overmature shale gas play. Because Longmaxi shale is Silurian marine strata without vitrinites, it is difficult to determine its maturity accurately. In order to evaluate the maturity of the Longmaxi shale exactly, in this paper, solid bitumen reflectance, basin modeling and laser Raman spectroscopy analyses of solid bitumen were carried out on the shale. The solid bitumen reflectance of Longmaxi shale is range of 2.77–4.14% with a mean of 3.5%, and the corresponding equivalent vitrinite reflectance (EqVRo) is 2.6%; additional information about the maturation is provided by the basin modeling with the constraint of the maximum paleo-geothermal about 210–220 °C which was indicated by thermo-acoustic emission measurement, fluid inclusion thermometry and equivalent vitrinite reflectance. In addition, the Raman was applied to Longmaxi shale in Jiaoshiba firstly, and the Raman inter-peak interval between peak G (graphitic band) and peak D (disordered band) is range of 270–279 cm−1, which suggests that equivalent vitrinite reflectance is about 2.67% and is consistent with the results of solid bitumen reflectance, infrared spectrum and basin simulation. Approximate conclusions have been drawn from these different methods, and the thermal evolution of Longmaxi shale in Jiaoshhiba area, the largest shale gas field in China, was estimated at approximately 2.5–2.7%, which means that it has reached the overmature dry gas stage. Overall, the findings also imply that Raman spectra of pyrobitumen can be used effectively to evaluate the maturation of the marine shale without vitrinites. [ABSTRACT FROM AUTHOR]

Silica‐phosphatic nodules are abundant in black shales of the Yanjiahe Formation in the Three Gorges Area of South China, which is correlated to the Fortunian Stage, Terreneuvian Series, Cambrian System. The nodules are rich in small shelly fossils and hence attract the attention of numerous paleontologists and sedimentary geologists. However, the genesis of the nodules and the preservation of the small shelly fossils are poorly understood. Here we analyze morphological, structural, mineralogical and chemical features of the nodules in multiscale using a combination of micro‐X‐ray fluorescence spectroscopy, X‐ray diffraction, scanning electron microscopy and confocal laser Raman spectroscopy. Results reveal that nodules are concentric in chemical and mineralogical compositions, comprising a silica‐phosphatic core encrusted sequentially by a phosphatic zone, a siliceous zone and a very thin pyrite outer rim. The black shales hosting the nodules demonstrate a laminated texture of alternating clayey and silty laminae, which were respectively deposited in sulfidic/less sulfidic, high/low production, intense/weak chemical weathering conditions. The phosphogenesis of the nodules resulted in the phosphatization of small shelly fossils, which prevented the fossils from being dissolved during diagenesis, whereas the silica encrustation sealed the fossils within the nodules and thus protected the fossils from alteration by deep burial and surface weathering. [ABSTRACT FROM AUTHOR]

Laser spectroscopy stands out as a powerful tool to investigate atomic and nuclear properties and also test fundamental theories by precisely measuring the energy levels in highly charged ions. In this work, the fine-structure splitting 1s 2 2s 2 S 1/2 − 1s 2 2p 2 P 1/2 transition in lithium-like 16O5+ has been investigated in a laser spectroscopy experiment at the heavy-ion storage ring CSRe. The excitation resonance of the tunable narrowband UV laser and the ions was observed using a Schottky resonator with very high sensitivity. The experimental uncertainties including the ion beam velocity determination, the space charge effects, laser wavelength calibration, and angular misalignment between the laser and ion beam were analyzed, and the 2 S 1/2 − 2 P 1/2 transition wavelength was determined to be λ 0 = 103.45(38) nm. The primary source of experimental uncertainty arises from the inaccurate measurement of the high voltage applied on the electron cooler and therewith the ion beam velocity at the CSRe. In order to solve this problem, a high-precision divider to precisely measure the high-voltage of the electron cooler is under construction, which is expected to improve the present experimental accuracy by three orders of magnitude. In addition, an XUV optical detector equipped with an off-axis parabolic mirror has been developed and installed at the CSRe for the investigation of slow dipole-forbidden transitions in highly charged ions, such as hyperfine splitting and M1 transitions. The experimental studies presented here pave the way for future laser spectroscopy experiments at the CSRe as well as at the future larger-scale scientific facility HIAF in China. [ABSTRACT FROM AUTHOR]

The color-change sapphire occurs in sillimanite-biotite gneiss in Fuping County Hebei province, China, is one of most famous sapphire deposits in China. However, the color genesis, mechanisms of color changing and compositional characteristics of the sapphire remain enigmatic. In this contribution, the coloration in the Fuping sapphire, color changing mechanisms and, compositional characteristics were studied by conventional gemological instruments in conjunction with ultraviolet-visible spectroscopy and Laser ablation inductively coupled plasma mass spectrometer. The results show that the Fuping sapphire is characterized by purple-blue-to-purple-red changed effect and column-shaped, waist drum-shaped with higher degree of euhedral crystal. Reddish brown rutile inclusions with 120° crossed cleavage are commonly observed. The dominant coloring element of the Fuping sapphire is Fe3+, and subordinate elements are Fe2+, Cr3+ and V3+. The color-change effect is caused by trace elements Cr3+ and V3+. The chemical compositions of Fuping color-change sapphires are analogous to those of metamorphic blue sapphires. When geochemically compared with sapphires from Isalo/Ilakaka deposit in Madagascar, Ratnapura deposit in Sri Lanka and Mogok in Myanmar, the Fuping color-change sapphires have distinctly higher rare element contents of Fe, Cr and Ga. [ABSTRACT FROM AUTHOR]

Various lines of evidence, including the occurrence of bitumen and fluid inclusions, show that oil charge once took place in the Kela-2 gas field, Kuqa foreland basin, Northwest China. However, the scale of the ancient oil reservoir remains unclear, as does the process by which the reservoir evolved into the present dry gas field. Here, using data from analyses of fluid inclusions, petrography, laser Raman spectroscopy, and quantitative fluorescence, the hydrocarbon accumulation history of the Kela-2 gas field is reconstructed. The results show that the gas field underwent three periods of hydrocarbon charging and one period of adjustment. The first oil charging occurred at about 12 Ma, as recorded by the first group of oil inclusions containing 0–8 vol.% gas with yellowish-brown fluorescence. The second charging involved mature oil charging at about 4 Ma, recorded by the second group of oil inclusions containing 15–25 vol.% gas with blue-white fluorescence. According to quantitative grain fluorescence (QGF) and rock pyrolysis analysis, an ancient oil reservoir existed with an oil-column height of about 350 m, and the paleo oil–water contact was lower than the present gas–water contact. Under intense thrusting from 3 Ma, the ancient oil reservoir was destroyed, with oil escaping through the Kashangtuokai thrust fault, which broke the salt layer, as this layer at that time lay in the brittle deformation domain. The inferred destruction of the ancient oil reservoir is supported by the numerous oil and gas shows at the surface and in shallow layers near the Kashangtuokai fault, as well as the anomalous development of authigenic kaolinite in the gas reservoir, which was enhanced by an open or semiopen system caused by the fault breaking through the salt layer. Subsequently, with increasing burial depth to more than 3000 m, the fault that had cut through the salt layer annealed because the salt layer then lay within the ductile deformation domain. The higher overpressure that occurred during the third gas charging at about 2 Ma reflected the annealing of the fault in the salt layer, favoring late gas accumulation and preservation. The evolution of the Kela-2 gas field provides an important case study for understanding the role of the salt layer crossing the brittle–plastic transition and the dynamic evolution of the salt caprock in salt-containing foreland basins. [ABSTRACT FROM AUTHOR]

The Dongjun Pb‐Zn‐Ag deposit in the northern part of the Great Xing'an Range (NE China) consists of quartz‐sulfide vein‐type and breccia‐type mineralization, related to granite porphyry. Hydrothermal alteration is well‐developed and includes potassic‐silicic‐sericitic alteration, phyllic alteration and propylitic alteration. Three stages of mineralization are recognized on the basis of field evidence and petrographic observation, demarcated by assemblages of quartz‐pyrite‐arsenopyrite (early stage), quartz‐polymetallic sulfide (intermediate stage) and quartz‐carbonate‐pyrite (late stage). Zircon LA‐ICP‐MS U‐Pb dating indicates that the granite porphyry was emplaced at 146.7 ± 1.2 Ma (Late Jurassic). Microthermometry and laser Raman spectroscopy shows that ore minerals were deposited in conditions of intermediate temperatures (175–359°C), low salinity (0.5–9.3 wt% NaCl eqv.) and low density (0.60–0.91 g/cm3). Ore‐forming fluids were derived largely from magmatic hydrothermal processes, with late‐stage addition of meteoric water, belonging to a H2O‐NaCl‐CO2 ± CH4 system. The δ34SV‐CDT values range from 0.75‰ to 4.70‰. The 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb values of the ore minerals are in the ranges of 18.240–18.371, 15.542–15.570, and 38.100–38.178, respectively. Data for the S and Pb isotopic systems indicate that the ore‐forming metals and sulfur were derived from Mesozoic magma. Based on the geological characteristics and geochemical signatures documented in this study, we conclude that the Dongjun deposit is a mesothermal magmatic hydrothermal vein‐type Pb‐Zn‐Ag deposit controlled by fractures and related to granite porphyry, in response to Late Jurassic tectonic–magmatic–hydrothermal activity. We further conclude that fluid immiscibility, fluid mixing and fluid‐rock interactions were the dominant mechanisms for deposition of the ore‐forming materials. [ABSTRACT FROM AUTHOR]

Natural lacquer has been used as a coating material for daily necessities for thousands of years. In the archeology and conservation science, identifying them provides useful information for the lacquer culture research and restoration work. In this study, an eared cup excavated in China was investigated by multiple analytical methods. The surface structure of ancient lacquerware has a multilayered structure. The type of lacquer was identified by pyrolysis gas chromatography/mass spectrometry (PyGC/MS). The layered structure and pigments were investigated by scanning electron microscopy/energy-dispersive X-ray spectrometry (SEM/EDX), which clearly showed elemental maps of the cross-section of the lacquer layers. Laser Raman spectroscopy (LRS) was used to distinguish between the types of carbon compound in the black layers. Additionally, the age of the eared cup was measured by radiocarbon dating. By combining these complementary results, we were able to derive a reliable interpretation of ancient lacquer processing techniques. This demonstrates the importance of properly combining multiple methods for analyzing the microscopic and complex structures of lacquerware. [ABSTRACT FROM AUTHOR]

Field monitoring of methane emissions from landfills is of great importance for both environmental concern and economic benefit. This study presents a highly effective method to measure methane emissions from landfills based on tunable diode laser absorption spectroscopy (TDLAS). Methane concentration is obtained by analyzing the absorption spectrum of the laser after passing through the landfill gas. The relationship between methane concentration and the optical signal was calibrated in the laboratory. As the methane concentration increased from 400 ppm to 5000 ppm, the absorption spectrum amplitude increased linearly from 0.0005 to 0.0046. In situ testing of methane emissions at a large-scale landfill in China demonstrated the accuracy of the TDLAS method. The methane concentrations in the well-covered areas were generally below 100 ppm. In the working area or the coverage area with holes, the methane concentration was about 700 ppm. The methane concentration was up to 1900 ppm, where the gas collection pipe is disconnected. Due to to the accuracy and simplicity, the TDLAS method is suitable to detect methane emissions on a large-scale from landfills. [ABSTRACT FROM AUTHOR]

Classic porphyry Cu–Mo deposits are mostly characterized by close temporal and spatial relationships between Cu and Mo mineralization. The northern Dabate Cu–Mo deposit is a newly discovered porphyry Cu–Mo polymetallic deposit in western Tianshan, northwest China. The Cu mineralization postdates the Mo mineralization and is located in shallower levels in the deposit, which is different from most classic porphyry Cu–Mo deposits. Detailed field investigations, together with microthermometry, laser Raman spectroscopy, and O‐isotope studies of fluid inclusions, were conducted to investigate the origin and evolution of ore‐forming fluids from the main Mo to main Cu stage of mineralization in the deposit. The results show that the ore‐forming fluids of the main Mo stage belonged to an NaCl + H2O system of medium to high temperatures (280–310°C) and low salinities (2–4 wt% NaCl equivalent (eq.)), whereas that of the main Cu stage belonged to an F‐rich NaCl + CO2 + H2O system of medium to high temperatures (230–260°C) and medium to low salinities (4–10 wt% NaCl eq.). The δ18O values of the ore‐forming fluids decrease from 3.7–7.8‰ in the main Mo stage to −7.5 to −2.9‰ in the main Cu stage. These data indicate that the separation of Cu and Mo was closely related to a large‐scale vapor–brine separation of the early ore‐forming fluids, which produced the Mo‐bearing and Cu‐bearing fluids. Subsequently, the relatively reducing (CH4‐rich) Mo‐bearing, ore‐forming fluids, dominantly of magmatic origin, caused mineralization in the rhyolite porphyry due to fluid boiling, whereas the relatively oxidizing (CO2‐rich) Cu‐bearing, ore‐forming fluids mixed with meteoric water and precipitated chalcopyrite within the crushed zone at the contact between rhyolite porphyry and wall rock. We suggest that the separation of Cu and Mo in the deposit may be attributed to differences in the chemical properties of Cu and Mo, large‐scale vapor–brine separation of early ore‐forming fluids, and changes in oxygen fugacity. [ABSTRACT FROM AUTHOR]

The Yuka gold deposit, located in the western part of northern Qaidam, contains Au orebodies hosted in early Paleozoic metamorphic basic volcaniclastic rocks. The Yuka mineralization can be divided into three stages: early quartz-pyrite (stage-I), middle quartz-gold-polymetallic sulfide (stage-II), and late quartz-carbonate (stage-III). Gold deposition is primarily contained within stage-II. Three types of fluid inclusions were identified in the vein mineral assemblages using petrography and laser Raman spectroscopy: H2O-CO2-NaCl (C-type), H2O-NaCl (W-type), and pure CO2 (PC-type). Stage-I fluids record medium temperatures (205.2°C to 285.5°C) and H2O-CO2-NaCl±CH4 fluids with variable salinities (0.6–8.5 wt.% NaCl equiv.). Stage-II fluids evolved towards a more H2O-rich composition within a H2O-CO2-NaCl±CH4 hydrothermal system at medium temperatures (193.1°C to 271.1°C), with variable salinities (0.4–11.7 wt.% NaCl equiv.). Stage-III fluids are almost pure H2O and characterized by low temperatures (188.1°C to 248.5°C) and salinities (0.4–16.1 wt.% NaCl equiv.). These data indicate that ore-forming fluids are characterized by low to medium homogenization temperatures and low salinity and are evolved from a CO2-rich metamorphogenic fluid to a CO2-poor fluid due to inputs of meteoric waters, which is similar to orogenic-type gold deposits. The average δ18OW of quartz varies from 3.3‰ in stage-I to 2.1‰ in stage-II and to 1.4‰ in stage-III, with the δD values ranging from −41.6‰ to −58.5‰, suggesting that ore-forming fluids formed from metamorphic fluids mixed with meteoric waters. Auriferous pyrite δ34S ranges from 0.5 to 7.4‰ with a mean value of 4.43‰, suggesting that fluids were partially derived from Paleozoic rocks via fluid-wall rock interactions. Auriferous pyrites have 206Pb/204Pb of 18.238–18.600 (average of 18.313), 207Pb/204Pb of 15.590–15.618 (average of 15.604), and 208Pb/204Pb of 38.039–38.775 (average of 38.1697) and stem from the upper crust. Basing on geological characteristics of the ore deposit as well as new data from the ore-forming fluids, and H-O-S-Pb isotopes, the Yuka gold deposit is best described as an orogenic-type gold deposit. [ABSTRACT FROM AUTHOR]

The Dayingezhuang gold deposit, hosted mainly by Late Jurassic granitoids on Jiaodong Peninsula in eastern China, contains an estimated 170 t of gold and is one of the largest deposits within the Zhaoping fracture zone. The orebodies consist of auriferous altered pyrite–sericite–quartz granites that show Jiaojia‐type (i.e., disseminated and veinlet) mineralization. Mineralization and alteration are structurally controlled by the NE‐ to NNE‐striking Linglong detachment fault. The mineralization can be divided into four stages: (K‐feldspar)–pyrite–sericite–quartz, quartz–gold–pyrite, quartz–gold–polymetallic sulfide, and quartz–carbonate, with the majority of the gold being produced in the second and third stages. Based on a combination of petrography, microthermometry, and laser Raman spectroscopy, three types of fluid inclusion were identified in the vein minerals: NaCl–H2O (A‐type), CO2–H2O–NaCl (AC‐type), and pure CO2 (PC‐type). Quartz crystals in veinlets that formed during the first stage contain mainly AC‐type fluid inclusions, with rare PC‐type inclusions. These fluid inclusions homogenize at temperatures of 251°C–403°C and have low salinities of 2.2–9.4 wt% NaCl equivalent. Quartz crystals that formed in the second and third stages contain all three types of fluid inclusions, with total homogenization temperatures of 216°C–339°C and salinities of 1.8–13.8 wt% NaCl equivalent for the second stage and homogenization temperatures of 195°C–321°C and salinities of 1.4–13.3 wt% NaCl equivalent for the third stage. In contrast, quartz crystals that formed in the fourth stage contains mainly A‐type fluid inclusions, with minor occurrences of AC‐type inclusions; these inclusions have homogenization temperatures of 106°C–287°C and salinities of 0.5–7.7 wt% NaCl equivalent. Gold in the ore‐forming fluids may have changed from Au(HS)0 as the dominant species under acidic conditions and at relatively high temperatures and fO2 in the early stages, to Au(HS)2– under neutral‐pH conditions at lower temperatures and fO2 in the later stages. The precipitation of gold and other metals is inferred to be caused by a combination of fluid immiscibility and water–rock interaction. [ABSTRACT FROM AUTHOR]

BACKGROUND: As the world's largest producer of synthetic diamonds, China accounts for more than 90% of the world's total production, of which high pressure-high temperature (HPHT) synthetic diamonds are dominant. Previous scholars have conducted many studies on analytical methods and property analysis of HPHT synthetic diamonds. However, the research on the pickling process after the growth of HPHT synthetic diamonds and the internal and external micro-structures after pickling is still insufficient. OBJECTIVES: To characterize 118 synthetic diamonds produced in China by high temperature and high pressure method. METHODS: The HPHT synthetic diamonds were observed by Laser Scanning Confocal Microscopy (LSCM) and ultra-depth-of-field 3D Microscopy, and the dark inclusions in these micro-structures were qualitatively analyzed by Laser Raman Spectroscopy. RESULTS:Three structure types were found. Step-like growth structures with certain angles revealed the crystallographic characteristics of HPHT synthetic diamond poly-crystals. Near-parallel linear scratches reflected the contact relationship between diamond grains in the growth chamber. The ‘rope-tied’ structures reflected the growth rate of HPHT synthetic diamonds. CONCLUSIONS: The micromorphology of these diamond surfaces reflects the growth conditions and environment of HPHT synthetic diamond gradient high temperature and continuous high pressure, which is of significance for the identification of HPHT synthetic diamonds. [ABSTRACT FROM AUTHOR]

The presence of graphite as a refractory form of solid carbon in high grade meta-sedimentary rocks serves as a valuable tool for identifying carbon sources and assessing the movement of carbon through the Earth's interior. In this study, we investigate the graphite formation processes from different lithologies (marbles, metapelites) from the Paleoproterozoic granulites in the southern margin of North China Craton. By utilizing a range of analytical techniques, including petrographic, mineral-chemical, laser Raman spectroscopic, carbon stable isotopic, and geochronological studies, we characterize the textural and isotopic variety of graphite and the timing of metamorphism associated with graphitization. The results suggest a progressive growth and graphitization of graphite during medium to high temperature metamorphic facies. The δ13C values of crystalline graphite in metapelites and marble range in −24.00‰ to −20.10‰, and − 22.50‰ to −21.60‰, respectively, both close to organic carbon averages. The calcite from the graphite-bearing marble shows δ13C values in the range of −2.90‰ to −2.80‰, which corresponds to marine carbonates. In contrast, graphite-bearing quartzo-feldspathic gneiss and diopside/augite-bearing marble show heavier isotopic values of −14.4‰ to −16.5‰, suggesting graphite precipitation from fluids of both organic and magmatic origin. The spectral and isotopic signatures of graphite in these rocks indicate a dominant biogenic signature with mixture of abiogenic carbon sources. Zircon U Pb geochronology marks the timing of high-grade metamorphism at ca. 1.93 to 1.92 Ga, associated with graphite formation during subduction and accretion process associated with the final assembly of the North China Craton. We propose that crystalline graphite was formed during the continental collision-triggered medium to high temperature metamorphic event, consistent with a global graphite metallogenic event in the Paleoproterozoic. • Mixed biogenic and abiogenic carbon sources signatures are identified via graphite. • The graphitization T is consistent with a medium to high-T metamorphism. • Graphitization occurred at ∼1.93–1.92 Ga associated with the final assembly of the NCC. [ABSTRACT FROM AUTHOR]

Many extraordinary cements, including mosaic dolomite, poikilitic celestine–barite, anhydrite and chemically zoned saddle-formed dolomite–ankerite, were observed in a reservoir sandstone unit underlying an evaporite sequence in the northern Bonan Sag, which is a saline lacustrine rift basin in the Jiyang Depression of Bohai Bay Basin, China. A suite of petrologic and chemical methods, including optical observation with cathode luminescence, fluid inclusion with laser Raman spectroscopy, X-ray fluorescence, and stable isotopes of carbon, oxygen and sulfur, were carried out. The results suggest that these extraordinary cements are mainly distributed near a fault zone and related to episodes of faulting events. Fault rupturing at shallow burial depths resulted in the dislocation of the evaporites and sandstones and made it possible for an influx of alkaline fluid from evaporites into the fault zone, where mosaic dolomite precipitated, and near fault reservoir units, such as where celestine–barite precipitated. Within the 'oil window', the reactivated normal faults, which induced a pressure drop in the reservoir unit, may have resulted in gas influx (e.g., CO 2 and H 2 S) and hydrocarbon charging, enhancing K-feldspar dissolution and cementation of assemblages of quartz, albite and illite. The cyclic fault rupturing and sealing in this setting probably resulted in repeated 'openness' of the diagenetic system, chemical perturbation of the pore fluids (e.g., pH dropping and returning), and cyclic dissolution–regrowth within the silicate–sulfate–carbonate diagenetic system. This study may highlight the awareness of diagenetic complexity in fault zones and shed light on reservoir evaluation in rift settings. • The fault-controlled authigenic cements of mosaic dolomite and poikilitic celestine–barite were observed in near-fault reservoir. • K-feldspar dissolution and cementation of assemblages of quartz, albite and illite are more developed in the vicinity of faults. • The curved dolomite–ankerite and associated blocky pyrite are suggested as the byproducts of thermochemical sulfate reduction. • Fault events are significant for cyclic dissolution-precipitation processes in the silicate-sulfate-carbonate system. [ABSTRACT FROM AUTHOR]

We have constructed a collinear laser spectroscopy (CLS) system installed at the Beijing Radioactive Ion-beam Facility (BRIF), aiming to investigate the nuclear properties of unstable nuclei. The first on-line commissioning experiment of this system was performed using the continuous stable (39K) and unstable (38K) ion beams produced by impinging a 100-MeV proton beam on a CaO target. Hyperfine structure spectra of these two isotopes are reasonably reproduced, and the extracted magnetic dipole hyperfine parameters and isotope shift agree with the literature values. The on-line experiment demonstrates the overall functioning of this CLS system, opening new opportunities for laser spectroscopy measurement of unstable isotopes at BRIF and other radioactive ion beam facilities in China. [ABSTRACT FROM AUTHOR]

[Display omitted] • The newly discovered Xiaokele Cu (–Mo) deposit is a typical porphyry deposit. • Cu (–Mo) mineralization is associated with Late Jurassic granodiorite porphyry. • Ore-forming fluids were magmatic in origin and mixed with meteoric water gradually. • Fluid cooling was the primary factor that controlled Cu precipitation. The Xiaokele Cu (–Mo) deposit is a newly discovered porphyry deposit in the northern Great Xing'an Range (GXR) of northeast China. The multiphase hydrothermal superposition on the Xiaokele Cu (–Mo) deposit obscures temporal relationships between quartz veins/veinlets in different mineralization stages, and consequently limits the understanding of the origin and evolution of the ore-forming fluids and metal precipitation mechanism. In this study, we document detailed descriptions of alteration and vein mineral paragenesis in the Xiaokele Cu (–Mo) deposit, present LA–ICP–MS zircon U–Pb and molybdenite Re–Os geochronology, the microthermometry and laser Raman spectroscopy of the fluid inclusions (FIs), and H–O–S–Pb isotope compositions. Four mineralization stages are identified, with stage II being the main Cu mineralization stage. The molybdenite Re–Os dating yielded a weighted average age of 148.7 ± 0.9 Ma (MSWD = 0.52), which is similar to the LA–ICP–MS zircon U–Pb age of 149.3 ± 0.9 Ma (MSWD = 0.15) yielded by the granodiorite porphyry. The δ34S V–CDT values of the sulfides (–1.2 to 2.4‰) conform the recognized magmatic sulfur values, indicating that the sulfur may have a magmatic origin. The Pb isotope compositions of the sulfides (206Pb/204Pb = 18.280–18.386, 207Pb/204Pb = 15.549–15.588, and 208Pb/204Pb = 38.153–38.359) coincide well with those of the Xiaokele granodiorite porphyry. These results indicate that the Xiaokele Cu (–Mo) deposit has a close genetic relationship with the granodiorite porphyry, and the ore-forming materials likely originated from the granodiorite porphyry. Petrographic/compositional characteristics of FI assemblages suggest that the ore-forming fluids belong to an H 2 O–NaCl–CO 2 system in stage I and an H 2 O–NaCl system from stages II to IV, and fluid boiling occurred from stages I to III. The FI homogenization temperatures show a decreasing trend from stages I to IV. The δ18O H2O values (6.4 to 7.7‰) of quartz in stages I and II are similar to typical magmatic water values, but the δD (–142.5 to –125‰) and δ18O H2O (–1.1 to 3.4‰) of quartz in stages III and IV are significantly lower than magmatic water values, indicating that the ore-forming fluids were magmatic in origin and gradually mixed with meteoric water from stages III to IV. Microthermometric data show that Cu-bearing sulfides in stage II were mainly deposited at a temperature below 400 °C, indicating that fluid cooling was the primary factor that controlled Cu precipitation in the Xiaokele Cu (–Mo) deposit. Our research on the Xiaokele porphyry Cu (–Mo) deposit will help to provide a scientific basis for future prospecting of this deposit and even the Late Jurassic porphyry deposits in the northern GXR. [ABSTRACT FROM AUTHOR]

[Display omitted] • Five stages of hydrothermal activity are identified. • The input fluids (ID 0,1) were derived from magma and characterized by high temperatures and intermediate density. • Multi-boiling processes have a great effect on the precipitation of Mo as molybdenite. • Molybdenum prefers to enrich in the brine phases. The Sadaigoumen porphyry Mo deposit is located on the northern margin of the North China Craton (NCC). In this study, in situ fluid-inclusion analyses including microthermometry, laser Raman spectroscopy, and LA–ICP–MS microanalysis, as well as Quartz H–O isotopes are present to precisely constrain the hydrothermal evolution of the Sadaigoumen deposit. Five stages of hydrothermal activity are identified, with Stage 1 characterized by the development of magnetite with rare sulfide minerals; Stage 2 by K-feldspar as the typical vein mineral; Stage 3 by molybdenite mainly in veins; Stage 4 by the development of fluorite–quartz and quartz–pyrite veins; and Stage 5 by barren carbonate–quartz veins. Fluid inclusion types were distinguished based on petrographic observations and microthermometric analysis, and fluid compositions were detected by LA–ICP–MS. Microthermometric analyses indicate decreasing homogenization temperatures in primary fluid inclusions from Stage 1 to Stage 3. Intermediate-density fluids of stages 1 and 2 are characterized by high homogenization temperatures (420 °C–470 °C), moderate salinities (6.3–11.2 wt%), and high Mo contents (52–541 ppm). Hydrothermal evolution during Mo mineralization in Stage 3 is characterized by immiscible inclusion assemblages that formed through phase separation from intermediate-density fluid. Fluid inclusions of Stage 3 were trapped at pressures fluctuating around the two-phase fluid surface, leading to at least two fluid immiscible phases (373 °C–414 °C and 311 °C–341 °C). The Mo contents of fluid inclusions vary greatly in Stage 3, with Mo tending to be enriched in brine. In stages 4 and 5, fluids display characteristics that indicate mixing with meteoric water, with homogenization temperatures (<299 °C) and salinities (<5.8 wt%) decreasing together with Mo content. The Cs/(Na + K + Mn + Fe) ratios of fluid inclusions are stable from stages 1 to 4, indicating a constant supply of ore-forming fluids from an underlying, geochemically uniform magma chamber. The fluid inclusion data suggest that Mo and Cu in the initial exsolved fluids of the Sadaigoumen porphyry Mo deposit display different migration and precipitation progresses, which is of great significance to the study of the delicate ore-forming progress of porphyry Mo (–Cu) deposits in the northern NCC. [ABSTRACT FROM AUTHOR]

The Permian reservoirs of Wangguantun Buried Hill are deep buried reservoirs in the Bohai Bay Basin, with a depth of more than 4000 m. The superposition of multi-stage tectonic movements also increases the complexity and unclear nature of the hydrocarbon charging and accumulation history. This study aims to address these issues by considering the structural evolution and burial–thermal history of the strata and studying the hydrocarbon expulsion process of source rocks by means of rock pyrolysis experiments. In addition, petrography, fluorescence spectroscopy, GC-MS (gas chromatography–mass spectrometry) of the oil from inclusions, laser Raman spectroscopy, and microthermometry of fluid inclusions were conducted and these analyses were coupled with cathodoluminescence tests of minerals and typical geological profiles to reveal the hydrocarbon charging process of the Permian reservoir in Wangguanshan Buried Hill. The results show that the oil of the Permian reservoirs in Wangguantun Buried Hill is generated from both upper Palaeozoic coal-measure and Paleogene lacustrine mudstone. The corresponding vitrinite reflectance (Ro) values at the expulsion thresholds of the Palaeozoic coal, Palaeozoic carbonaceous mudstone, Palaeozoic mudstone, and Paleogene mudstone are 0.68%, 0.72%, 0.72% and 0.73%, respectively. The Permian reservoirs have experienced three oil and gas charging periods. In the first period, during the late Jurassic to early Cretaceous (135–100 Ma), the reservoirs were charged primarily with less mature oil. The subsequent uplift of the strata in the late Cretaceous exposed the ancient reservoir, and most of the oil transformed into carbonaceous bitumen. In the second period, the middle and late Paleogene (45–33 Ma), the reservoirs were charged primarily with less mature oil from the Paleogene source rocks and mature to highly mature oil and gas from the coal-measure source rocks. In the third period, from the late Neogene to the present (12–0 Ma), the reservoirs were primarily charged with highly mature oil from the Paleogene mudstone and highly mature and overmature oil and gas from the coal-measure. Fractures provide the main storage space for hydrocarbons, while some were stored in intergranular and dissolved pores. Consequently, fractured reservoirs should be important targets for gas and petroleum exploration in such deep reservoirs. In addition, the regional structure evolution controlled the hydrocarbon expulsion and charging processes, which guided the formulation of the hydrocarbon accumulation model of the Permian reservoir. • For the first time, three periods of hydrocarbon charging were proposed for the study area. • Diagenesis and hydrocarbon charging processes of the reservoir were discovered. • The origin of oil was determined by the GC-MS characteristics of the oil separated from the inclusions. • The role and the significance of micro-fractures in the exploration of deep buried reservoirs was determined. [ABSTRACT FROM AUTHOR]

• Ore-forming fluids of stratiform mineralization belong to a NaCl-H 2 O system. • Those of vein-type mineralization are attributed to a NaCl-H 2 O-CO 2 system. • Ore-forming materials of vein-type mineralization were partly from stratiform ores. • Paleoproterozoic stratiform mineralization is typical of SEDEX-type deposits. • Vein-type mineralization represents a moderate-temperature hydrothermal deposit. 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), CO 2 -bearing (types 3a and 3b), and CO 2 -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–H 2 O 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–H 2 O–CO 2 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. [ABSTRACT FROM AUTHOR]

The article presents fluid inclusion studies related to precipitation of Gold in the Xincheng Deposit in Jiaodong Peninsula, China. Several methods employed for identifying three types of fluid inclusions in gold bearing quartz include petrography, microthermometry and Raman Laser Spectroscopy. It discusses the fluid inclusion shown by quartz-pyrite and quartz-sulphide veins in the Xincheng Deposit and investigates the fluid immiscibility taking place at the deposit.