Abstract:Large quantities of magmatic rocks are developed on the southern margin of Gangdise belt. Previous studies mainly focused on the eastern part of this magmatic rock belt, which completed the theory of the tectonic framework and lithospheric structure as well as the evolution of the southern margin of the Gangdise belt. The Amuxiong complex is in the middle part of the magmatic rock belt on the southern margin of the Gangdise belt. The authors described zircon U-Pb geochronology, zircon Hf isotope and whole-rock geochemical analyses of hornblende gabbro and biotite monzonitic granite of the Amuxiong complex, discussed the emplacement order of these two types of magma, and clarified the genesis of magma and the hypogene geological process of the magma source area. The zircon U-Pb dating results of the biotite monzonitic granite and the hornblende gabbro are both at 49 Ma, suggesting magmatism of the Eocene period. The biotite monzonitic granite is I-type calc-alkaline granite, characterized by enrichment of the large ion lithophile elements (LILE), and depletion of the high field strength elements (HFSE), with the small positive εHf(t) value of -0.2~+2.6 and the Hf isotopic crustal model age t_DM^C of 1 136~393 Ma, suggesting that this hornblende gabbro belongs to typical gabbro. The rare earth element patterns show a gentle right wing, with very slight negative Eu anomalies, whereas the trace element pattern shows the enrichment of LILE and depletion HFSE, with the high positive εHf(t) value of +5.1~+16.8 and the young t_DM^C age of 798~46 Ma. The analytical results suggest that the hornblende gabbro was derived from the depleted mantle that had undergone lamellar fluid replacement, and that, after some differentiation, the magma of monzonite was derived from partial melting of juvenile lower crust and a small amount of old continental crust. There have been some disputes about the origin of the ancient materials in this area. Based on the analysis of previous results and the characteristics of magmatic rocks in this study, the authors hold that the contribution of the ancient materials came from the old Central Lhasa subterrane. By comparing the magmatism of the Gangdise magmatic belt in the same period, it is concluded that the main inducing mechanism of the magmatism of the Amuxiong complex might have been plate break off.

Abstract:The Wang'ershan gold deposit is located in southern Wang'ershan fault belonging to the Jiaojia gold orefield and lies in the western part of Zhaoyuan-Laizhou gold ore belt of Shandong Province. As a large-scale gold deposit, it combines the characteristics of both altered rock type and quartz vein type. Systematic sampling was conducted. The typomorphic characteristics of pyrite and its prospecting significance were discussed. The chemical composition of pyrite is characterized by sulfur depletion and relative enrichment of Au, Ag, Cu, Pb, Zn, As, Co, Ni and Se as trace elements. The occurrence ratio of P-type pyrite is 29.4% in the Wang'ershan deposit. The parameters of thermoelectricity and thermal resistance of pyrites are closely related to gold grade in time and space. The metallogenic temperatures are concentrated in 130.3~339.8℃ according to the thermoelectric coefficient-temperature scale. Cell parameters (a₀ and v₀) and half-peak bandwidth of X-ray diffraction in pyrites are low, with the feature of deep-derived source. δFe-δS plots and lattice parameter a₀ show that the Wang'ershan gold deposit might be a mid-low temperature hydrothermal deposit with relatively serious denudation. It may grade into altered rock type in the deep part.

Abstract:The Jiaodong gold province contains more than 4 000 tons of gold reserves and is hence the most important gold-producing area in China. The gold deposits are mainly controlled by the NE-striking Sanshandao, Jiaojia, and Zhaoping faults from west to east, and form three gold metallogenic belts. In order to explore the source of ore-forming fluids in these metallogenic belts, the authors investigated He and Ar isotopes of fluid inclusions in the gold-bearing pyrite form several typical deposits, and the results show that the mean ratio of ³He/⁴He is 1.95 Ra in the Sanshandao belt, 1.74 Ra in the Jiaojia belt, and 1.54 Ra in the Zhaoping belt, with a decreasing trend from west to east. The values of radioactive Ar are 1.17%~87.12% (averagely 33.04%) in Sanshandao, 15.57%~90.00% (averagely 55.75%) in Jiaojia, and 7.94%~92.69% (averagely 44.23%) in Zhaoping, suggesting that the highest contribution of crustal fluids was from Jiaojia, the medium contribution was from Zhaoping, and the lowest contribution was from Sanshandao. Combined with H-O isotopic data, the authors hold that the ore-forming fluids in the Jiaodong gold province were mainly mixed crust-derived and mantle-derived fluids, with possible contribution of meteoric water during the fluid ascending.

Abstract:Diamonds are very rare in nature and are hence extremely precious mineral resources. The diamond of metamorphic origin, discovered in several ultrahigh pressures metamorphic zones in the world, has improved our understanding of ultrahigh pressure metamorphism and plate tectonic movement. Moreover, it has promoted the research on geodynamics of ultrahigh pressure metamorphic belt and attracted extensive attentions. However, further discussion is needed on the formation mechanism of metamorphic diamond. Based on recent research results, the authors described the tectonic background for the formation of metamorphic diamond, studied the geological environment and temperature-pressure conditions and discussed the origin of the diamond in the ultrahigh-pressure metamorphic zone. When the peak pressure of metamorphism reaches the stable region of diamond and has a higher temperature (pressure>3 GPa, temperature 600℃~1 000℃), the conditions are beneficial to the formation of diamond. Higher CO₂ content and lower oxygen fugacity in C-O-H fluids are also essential for diamond formation in ultrahigh pressure metamorphic belts. In addition, the cooling effect at the early exhumation is favorable for its preservation.

Abstract:Na_xWO₃ (0 ≤ x ≤ 1) has received increasing attention from experts due to its special physicochemical properties. It is a non-stoichiometric W-containing compound with the tunnel structure, and Na⁺ filled in the secondary structural tunnels produced by the connection of octahedron. With the increase of x, the average oxidation degree of W decreases gradually, Na_xWO₃ undergoes monoclinic-orthogonal-tetragonal Ⅰ (space group I4/nmm)-hexagonal-tetragonal Ⅱ (space group P4/mbm)-cubic crystal structure transformation. Structural symmetry gradually increases except for the tetragonal Ⅱ type. In this paper, the structural characteristics of sodium tungsten bronze with di-fferent W oxidation degrees were systematically studied from the perspective of crystal chemistry. The tetragonal and cubic phase sodium tungsten bronze was obtained by solid phase synthesis, and the hexagonal tungsten bronze was obtained by hydrothermal synthesis. Experimental results show that, in the solid phase synthesis process, the more the reducing agent NaBH₄, the more the reduction of W to a lower valence state, and the easier the conversion of the Na_xWO₃ from the tetragonal to cubic structure. At the same reduction dose, the higher the synthesis temperature, the higher the symmetry of the obtained sodium tungsten bronze. The temperature of synthetic cubic sodium tungsten bronze is 700~850℃, which is higher than the synthesis temperature of tetragonal sodium tungsten bronze (600~700℃); the synthesis reaction requires appropriate pH value, the pH value is controlled at around 6 when tetragonal and cubic sodium tungsten is synthesized, and the pH value of the hydrothermally synthesized hexagonal sodium tungsten bronze is preferably around 2. The result obtained by the authors provides a reference for sodium tungsten bronze series compounds and the synthesis of different structures of sodium tungsten bronze.

Abstract:Collecting four different types of arsenic-containing minerals in Shimen realgar mining area, using Thiobacillus ferrooxidans(T. f), sulfate reducing bacteria(SR) and Acidiphilium cryptum JF-5(JF-5) to investigate the release of arsenic from primary and secondary arsenic-containing minerals under biological reduction and oxidation conditions to determine the potential risk of arsenic release. Quantitative analysis by ICP-OES showed that the concentration of arsenic in both realgar tailing and orpiment tailing was increasing under the action of the above T. f, SR and JF-5. Arsenic released at 168 h under the action of T. f:orpiment tailing > leachate secondary arsenic-containing tailing > realgar tailing > arsenic containing clip rock tailing. The results of LC-AFS atomic fluorescence spectrometry release showed that:① Under the action of T. f, realgar tailing and orpiment tailing showed very obvious differences; after 1.5 h, the order of releasing As(V) for four arsenic-containing minerals is:arsenic containing clip rock tailing > realgar tailing > leachate secondary arsenic-containing tailing > orpiment tailing; ② Under the action of JF-5 and SR, SR can promote the release of As(Ⅲ) from the orpiment tailing, which is twice as much as JF-5; the orpiment tailing releases As(Ⅲ) reached to 20.64 mg/L (SR) and 9.54 mg/L (JF-5) at 168 h. The order of release of As(Ⅲ) from four arsenic-containing minerals under the action of SR at 96 h was:orpiment tailing > leachate secondary arsenic-containing tailing > arsenic containing clip rock tailing > realgar tailing; the order of release of As(III) by four arsenic-containing minerals after 96 h of action of JF-5 is realgar tailing > orpiment tailing > arsenic containing clip rock tailing > leachate secondary arsenic-containing tailing.

Abstract:To explore the molecular mechanism of quartz dust in the atmospheric particulates exacerbating respiratory inflammatory response, the authors used XRD to analyze the phase of quartz dust, and utilized bronchial epithelial cells as the target. After the cells were treated by quartz dust for 24 h, CCK-8 was used to detect cell viability and the concentration of interleukin-6 (IL-6) and interleukin-8 in the culture supernatant was detected by ELISA. Western Blot was used to detect the expression of TLR4. The levels of IL-6, IL-8 and TLR4 were detected after being pretreated with Toll like receptor 4 specific inhibitor TAK 242. According to the results, the main phase of quartz dust was quartz, including partial calcite; the relative cell survival ratio decreased with the increase of quartz dust concentration; the concentration of IL-6 and IL-8 in the supernatant of the 100 μg/mL group was significantly increased compared with the control group (P<0.01); high levels of IL-6 and IL-8 in the 50, 75, and 100 μg/mL groups were antagonized by TAK 242; after being pretreated with TAK 242, IL-6 and IL-8 were significantly reduced in the 100 μg/mL group (P<0.01); the expression of TLR4 increased with the increase of quartz dust concentration, and the intervention of TAK 242 could effectively prevent the activation of TLR4 pathway. In summary, it can be concluded that exposure to quartz dust can stimulate the secretion of high concentrations of inflammatory factors in bronchial epithelial cells, and the mechanism may be the activation of TLR4 signaling pathway.

Abstract:Based on a systematic collection of 108 new minerals approved by the Commission on New Minerals,Nomenclature and Classification (CNMNC) of the International Mineralogical Association (IMA) in 2017, this paper gives an account of main mineralogical characteristics of these new minerals, which include mineral names, crystallochemical formulae,crystal structure data,physical and optical properties, origin and occurrence localities, and relationships with other minerals. It is worth noticing that Chinese names of these new minerals have been examined and revised under the authority of Chinese Commission of New Minerals and Mineral Names. Presenting a report of the comprehensive introduction to discovery and study of new minerals in the world, this work will provide valuable reference for discovery and study of new minerals in China and promote the standardization of Chinese names of mineral species.