Fluid inclusion and H-O-S-Pb isotope systematics of the Chayong Cu-polymetallic deposit,Sanjiang Metallogenic Belt,Qinghai Province,China

The Chayong Cu-polymetallic deposit is a recently discovered Cu-polymetallic deposit hosted in the Sanjiang Metallogenic Belt within the Tibetan Plateau of China to the northeast of the North Qiangtang terrane.The ore body occurs in siltstone and is controlled by a northwest-trending fault structure.According to the associations,assemblages,and cutting relationships between ore veins,the hydrothermal mineralization period can be divided into three mineralization stages:(1)a molybdenite mineralization stage,(2)a Cu-polymetallic sulfide stage,and(3)a quartzcarbonate stage.Two types of fluid inclusions(FIs),namely,liquid and vapor-rich inclusions,are present in quartz as so ciated with sulfide minerals.Early-stage FIs are both iquid and vapor-rich,homogenized at temperatures ranging from 364.1 to 384.2℃,and have salinities ranging from0.70%to 9.60%NaCl equivalent(eqv).The middle-stage FIs are also both liquid-and vapor-rich,homogenized at temperatures ranging from 272.4 to 355.6℃,and have salinities ranging from 0.53%-17.10%NaCl eqv.The late-stage FIs are liquid,homogenized at temperatures ranging from 209.4to 255.3℃,and have salinities ranging from 0.35%-6.87%NaCl eqv.The samples from the deposit haveδ^(34)S values of-21.8‰to-19.2‰and-5.5‰to-6.0‰,suggesting that sulfur was derived from the host sediments and magmatic fluids,respectively.The metallic minerals within the deposit have^(206)Pb/^(204)Pb,^(207)Pb/^(204)Pb,and^(208)Pb/^(204)Pb values of 18.439-18.458,15.656-15.679,and 38.772-38.863,respectively,suggesting that the metals were derived from the upper crust and orogenic belts.The samples from the deposit haveδ^(18)O_(W)values of 2.99‰-7.99‰andδD_(W) values ranging from-84.4‰to-73.9‰,indicating that the pre-forming fluids were magmatic and mixed with minor amounts of meteoric water.The ore-forming fluid of the Chayong copper polymetallic deposit was a high-temperature,medium-to low-salinity H_(2)O-NaCl-CH_(4)-N_(2)±CO_(2)fluid system.The early high-temperature magmatic fluid,due to boiling,decreased in temperature,and via the mixing of meteoric water,gradually evolved towards the later-stage medium-to low-temperature and low-salinity fluid,causing nolybdenite mineralization and forming copper polymetallic sulfide veins and quartz carbonate veins.

Discourse Analysis of the Belt and Road Initiative From the Perspective of Central Asian Countries: A Case Study of the Republic of Kazakhstan

This study employs Norman Fairclough’s Critical Discourse Analysis(CDA)three-dimensional model,using the Republic of Kazakhstan as a case study,to delve into the discourse construction of China’s Belt and Road Initiative(BRI)in Central Asian countries.Through detailed analysis of policy documents,media reports,and public discussions in Central Asian countries,this paper reveals how the BRI constructs specific social practices,discourse events,and textual meanings within these nations.The findings indicate that through this global development strategy,China has not only strengthened its economic ties with Central Asian countries but has also exerted profound influences on political,cultural,and social levels.

The 600 keV electron injections in the Earth's outer radiation belt:A statistical study

Relativistic electron injections are one of the mechanisms of relativistic(≥0.5 MeV) electron enhancements in the Earth’s outer radiation belt. In this study, we present a statistical observation of 600 keV electron injections in the outer radiation belt by using data from the Van Allen Probes. On the basis of the characteristics of different injections, 600 keV electron injections in the outer radiation belt were divided into pulsed electron injections and nonpulsed electron injections. The 600 keV electron injections were observed at 4.5 < L <6.4 under the geomagnetic conditions of 450 nT < AE < 1,450 nT. An L of ~4.5 is an inward limit for 600 keV electron injections. Before the electron injections, a flux negative L shell gradient for ≤0.6 MeV electrons or low electron fluxes in the injected region were observed. For600 keV electron injections at different L shells, the source populations from the Earth’s plasma sheet were different. For 600 keV electron injections at higher L shells, the source populations were higher energy electrons(~200 keV at X ~–9 R_(E)), whereas the source populations for 600 keV electron injections at lower L shells were lower energy electrons(~80 keV at X ~–9 R_(E)). These results are important to further our understanding of electron injections and rapid enhancements of 600 keV electrons in the Earth’s outer radiation belt.

A data assimilation-based forecast model of outer radiation belt electron fluxes

Because radiation belt electrons can pose a potential threat to the safety of satellites orbiting in space,it is of great importance to develop a reliable model that can predict the highly dynamic variations in outer radiation belt electron fluxes.In the present study,we develop a forecast model of radiation belt electron fluxes based on the data assimilation method,in terms of Van Allen Probe measurements combined with three-dimensional radiation belt numerical simulations.Our forecast model can cover the entire outer radiation belt with a high temporal resolution(1 hour)and a spatial resolution of 0.25 L over a wide range of both electron energy(0.1-5.0 MeV)and pitch angle(5°-90°).On the basis of this model,we forecast hourly electron fluxes for the next 1,2,and 3 days during an intense geomagnetic storm and evaluate the corresponding prediction performance.Our model can reasonably predict the stormtime evolution of radiation belt electrons with high prediction efficiency(up to~0.8-1).The best prediction performance is found for~0.3-3 MeV electrons at L=~3.25-4.5,which extends to higher L and lower energies with increasing pitch angle.Our results demonstrate that the forecast model developed can be a powerful tool to predict the spatiotemporal changes in outer radiation belt electron fluxes,and the model has both scientific significance and practical implications.

Origin of Paleofluids in Dabashan Foreland Thrust Belt:Geochemicai Evidence of ^(13)C,^(18)O and ^(87)Sr/^(86)Sr in Veins and Host Rocks

In the last ten years, with important discoveries from oil and gas exploration in the Dabashan foreland depression belt in the borderland between Shanxi and Sichuan provinces, the relationship between the formation and evolution of, and hydrocarbon accumulation in, this foreland thrust belt from the viewpoint of basin and oil and gas exploration has been studied. At the same time, there has been little research on the origin of fluids within the belt. Based on geochemical system analysis including Z values denoting salinity and research on δ13C, δ18O and S7Sr/S6Sr isotopes in the host rocks and veins, the origin of paleofluids in the foreland thrust belt is considered. There are four principal kinds of paleofluid, including deep mantle-derived, sedimentary, mixed and meteoric. For the deep mantle-derived fluid, the δ13C is generally less than -5.0‰PDB, δ18O less than -10.0‰PDB, Z value less than 110 and 87Sr/86Sr less than 0.70600; the sedimentary fluid is mainly marine carbonate- derived, with the δ13C generally more than -2.0‰PDB, 18δO less than -10.0‰PDB, Z value more than 120 and STSr/S6Sr ranging from 0.70800 to 0.71000; the mixed fluid consists mainly of marine carbonate fluid （including possibly a little mantle-derived fluid or meteoric water）, with the j13C generally ranging from -2.0‰ to -8.0‰PDB, δ18O from -10.0‰ to -18.0‰ PDB, Z value from 105 to 120 and 87Sr/86Sr from 0.70800 to 0.71000; the atmospheric fluid consists mainly of meteoric water, with the δ13C generally ranging from 0.0‰ to -10.0‰PDB, δ18O less than -8.0%rPDB, Z value less than 110 and 87Sr/86Sr more than 0.71000. The Chengkou fault belt encompasses the most complex origins, including all four types of paleofluid; the Zhenba and Pingba fault belts and stable areas contain a simple paleofluid mainly of sedimentary type; the Jimingsi fault belt contains mainly sedimentary and mixed fluids, both consisting of sedimentary fluid and meteoric water. Jurassic rocks of the foreland depression belt contain mainly meteoric fluid.

The"Belt and Road"Initiative:A Chinese Concept for Global Development

China＇s ＂Belt and Road＂ initiative is emerging as the Western-dominated world order is declining. Capitalism has intensified the rich-poor divide and power politics have led to great upheavals. Western values have caused a ＂value dislocation＂ for non-Western countries. The world is calling for new development concepts. The ＂Belt and Road＂ initiative has emerged as an answer. It embodies China＇s ideas on global development. First, it works for the ＂common prosperity＂ of every country, which will ease contradictions between the South and the North. Second, it emphasizes geo-economie integration that will heal the fragmentation of Eurasia. Third, it advocates linkages between people and inclusiveness to create a new kind of civilization. However, many difficulties and challenges lie ahead for the implementation of the ＂Belt and Road＂ initiative.

Modeling the energetic electron fluxes in the inner radiation belt based on a drift-source model

The Macao Science Satellite-1(MSS-1),designed by the Macao University of Science and Technology and the National Space Science Center(NSSC)of China,is equipped to detect the fine structure of the magnetic field over the South Atlantic Anomaly(SAA)region,monitoring geomagnetic field variations,and obtaining the energetic electron spectrum distributions in the Earth’s inner radiation belt.In this study,we simulate the distributions of trapped,quasi-trapped,and untrapped electrons along the orbit of MSS-1 based on a drift-source model.The simulation results show that the particle detector with 90°looking direction can observe trapped electrons in the SAA region,untrapped electrons in the regions conjugated with the SAA region at the north hemisphere,and quasitrapped electrons in all other regions.In contrast,the detectors with<60°looking directions can measure only untrapped electrons.Generally,quasi-trapped electron fluxes accumulate along the drift trajectory and are due primarily to CRAND,until reaching the SAA region where quasi-trapped electrons are all lost into the atmosphere.

The Paleoarchean Northern Mundo Novo Greenstone Belt,São Francisco Craton:Geochemistry,U-Pb-Hf-O in zircon and pyriteδ^(34)S-Δ^(33)S-Δ^(36)S signatures

Greenstone belts contain several clues about the evolutionary history of primitive Earth.Here,we describe the volcano-sedimentary rock association exposed along the eastern margin of the Gavião Block,named the Northern Mundo Novo Greenstone Belt(N-MNGB),and present data collected with different techniques,including U–Pb–Hf–O isotopes of zircon and multiple sulfur isotopes(^(32)S,^(33)S,^(34)S,and ^(36)S)of pyrite from this supracrustal sequence.A pillowed metabasalt situated in the upper section of the N-MNGB is 3337±25 Ma old and has zircon with ε_(Hf)(t)=2.47 to1.40,Hf model ages between 3.75 Ga and 3.82 Ga,and δ^(18)O=+3.6‰to+7.3‰.These isotopic data,together with compiled whole-rock trace element data,suggest that the mafic metavolcanic rocks formed in a subduction-related setting,likely a back-arc basin juxtaposed to a continental arc.In this context,the magma interacted with older Eoarchean crustal components from the Gavião Block.Detrital zircons from the overlying quartzites of the Jacobina Group are sourced from Paleoarchean rocks,in accordance with previous studies,yielding a maximum depositional age of 3353±22 Ma.These detrital zircons have ε_(Hf)(t)=5.40 to0.84,Hf model ages between 3.66 Ga and 4.30 Ga,and δ^(18)O=+4.8‰to+6.4‰.The pyrite multiple sulfur isotope investigation of the 3.3 Ga supracrustal rocks from the N-MNGB enabled a further understanding of Paleoarchean sulfur cycling.The samples have diverse isotopic compositions that indicate sulfur sourced from distinct reservoirs.Significantly,they preserve the signal of the anoxic Archean atmosphere,expressed by MIF-S signatures(Δ^(33)S between1.3‰to+1.4‰)and a Δ^(36)S/Δ^(33)S slope of0.81 that is indistinguishable from the so-called Archean array.A BIF sample has a magmatic origin of sulfur,as indicated by the limited Δ^(34)S range(0 to+2‰),Δ^(33)S~0‰,and Δ^(36)S~0‰.A carbonaceous schist shows positive Δ^(34)S(2.1‰–3.5‰)and elevated Δ^(33)S(1.2‰–1.4‰)values,with corresponding negative Δ^(36)S between1.2‰to0.2‰,which resemble the isotopic composition of Archean black shales and suggest a source from the photolytic reduction of elemental sulfur.The pillowed metabasalt displays heterogeneous Δ^(34)S,Δ^(33)S,and Δ^(36)S signatures that reflect assimilation of both magmatic sulfur and photolytic sulfate during hydrothermal seafloor alteration.Lastly,pyrite in a massive sulfide lens is isotopically similar to barite of several Paleoarchean deposits worldwide,which might indicate mass dependent sulfur processing from a global and well-mixed sulfate reservoir at this time.

The NE Directed Seismicity Belt in Tibet after the M_S8.1 Nepal Earthquake and Its Predictive Significance

After the 2015 M_S8. 1 Nepal earthquake,a strong and moderate seismicity belt has formed in Tibet gradually spreading along the northeast direction. In this paper,we attempt to summarize the features and investigate the primary mechanism of this behavior of seismic activity,using a 2-D finite element numerical model with tectonic dynamic settings and GPS horizontal displacements as the constraints. In addition,compared with the NEtrending seismicity belt triggered by the 1996 Xiatongmoin earthquake,we discuss the future earthquake hazard in and around Tibet. Our results show that: the NE-directed seismicity belt is the response of enhanced loading on the anisotropic Qinghai-Tibetan plateau from the Indian plate and earthquake thrusting. Also,this possibly implies that a forthcoming strong earthquake may fill in the gaps in the NE-directed seismicity belt or enhance the seismic hazard in the eastern( the north-south seismic zone) and western( Tianshan tectonic region) parts near the NE-directed belt.

Australia’s Fear and Greed over China’s Rise:A Discourse Analysis of Mainstream News Coverage of the Belt and Road Initiative

China’s rise has stirred up world-wide debate.In Australia,China has been one of the keywords in its foreign and strategic policies and on news media.Its rise intensifies the dual functions―benefit provider and security offender to Australia and the tensions between greed of economic gains and fear of China’s increasing geopolitical strength and influence.The“fear and greed”narration is well-presented on Australian mainstream media.Such ambivalence can also find its expressions in the recent typical case of China’s rise―the Belt and Road Initiative.It is worthwhile to find out how Australia’s ambivalence to BRI and China’s rise is represented on media and to draw the sociopolitical inferences behind“fear and greed”.The thesis is going to take BRI as a typical example of China’s rise to examine the ambivalent“fear and greed”narration on Australian mainstream news media.Data sample includes news reports of BRI from ABC News,The Australian,The Australian Financial Review,The Sydney Morning Herald,and The Age from September 1st,2013 to October 31st,2017.The discourse analysis on China’s images finds that Australia is rather biased against China,regarding China both as a lucrative friend and a threatening enemy.The bias lingers on for centuries and generates misunderstanding,mistrust,and anxiety.Profit drives Australia to establish closer economic ties with China,while value differences would not allow too much proximity but help to maintain a robust alliance with its allies.Australia’s position between its major economic partner and traditional allies has caused much concern and will have a long-term influence on its policy-making decisions.

Research on the Investment Effect of Chinese Cultural “Going Out” —Empirical Evidence from the Countries along the “Belt and Road”

This paper is based on 2006-2017 relevant data of 56 countries along the “Belt and Road” to find out the investment effect of cultural “going out”. The empirical results show that: cultural “going out” has a significant promotion effect on China’s foreign direct investment;this effect has national heterogeneity, which is more effective for emerging markets and developing countries;for some traditional influence factors, such as traditional GDP per capita and time for diplomatic relations, cultural “going out” has a substitution effect. Finally, according to the empirical results, put forward targeted suggestions.

The Belt and Road Initiatives and China＇s Middle East Energy Policy

The paper analyses the roots of the Belt and Road Initiative as well as China＇s Middle East Energy Policy in an age of great transformation. China＇s rapidly progressed economic growth leading to a dramatic increase in China＇s energy demand in recent years. The Middle East countries play a critical role in the international energy markets. Stable relations with the Middle East countries become increasingly important for Chinese energy security, and the continued development. The protection of these relations lies at the core of the Belt and Road Initiative. Within The Belt and Road Initiative, Chinese Middle East energy policy proceeds according to the energy cooperation framework known as ＂1＋2＋3＂, which seeks to build a reliable China-Arab strategic cooperative relationship based on long-term friendship. To avoid over dependence on the energy resources of the Middle East, China will also continue to search for other overseas energy sources and protect transportation channels. Despite risks and challenges associated with energy imports from the Middle East, China has cultivated strong relations with states in the region and will develop these economic ties further in the coming years.

The Belt and Road Initiatives and China＇s International Energy Cooperation： Progress, Mechanisms, and Recommendations

China＇s international energy cooperation and energy security are important parts of The Belt and Road initiatives. China and the countries along the Belt and Road continue to promote cooperation, actively use the existing bilateral and multilateral cooperation mechanisms to promote the regional and inter-regional energy cooperation. Countries along the Belt and Road are rich in oil and gas resources; their demand on the diversification of export meet with the diversification demand on imports of consumption countries; and their oil refining and chemical technology as well as construction capacity is weak, which provides a lot of new opportunities in cooperation for Chinese enterprises. However, the energy cooperation of Chinese enterprises are also facing some challenges in the complex environment of energy cooperation, the interference of big powers, non-traditional security threats, and energy policy factors. Finally, the paper puts forward the strategic thinking of China＇s international energy cooperation under the new situation.

扭紧力矩对SWRM10K螺栓疲劳性能影响的研究

对扭紧力矩分别为0、12.5、22.0、29.5和35.0 Nm的SWRM10K钢螺栓进行轴向加载疲劳实验,获取螺栓的疲劳S-N数据。对比不同扭紧力矩下螺栓疲劳S-N特性,分析扭紧力矩对螺栓疲劳性能的影响。采用SEM观察螺栓试样的断口形貌,结合EDS分析裂纹萌生区元素分布,揭示螺栓疲劳断裂的规律。研究结果表明:增加扭紧力矩能有效提升该螺栓疲劳极限,但增加到一定程度提升效果明显下降,扭紧力矩值接近29.5 Nm较为合理。在该扭紧力矩下,螺栓疲劳极限为141 MPa,与未施加扭紧力矩相比提升了62.1%。螺栓疲劳断口分为3个区域:裂纹萌生区、扩展区和瞬间断裂区。在高应力幅下,裂纹萌生于试样表面,由晶体滑移引起;在低应力幅下,裂纹同样萌生于试样表面,但由晶体滑移或夹杂物引起。

A Study on the Belt and Road Initiative and the Promotion of International Competitiveness of China's Culture Industry

China's pioneering the Belt and Road initiative not only provides a broad space for China's culture industry to enhance international competitiveness, but also puts forward a major project. It includes: optimize and integrate strategic resources through connectivity, cultivate export-oriented cultural enterprises to promote the main body of the industry, optimize the structure of cultural trade by expanding cultural services exports, and build win-win cooperation networks through the connections between Silk Road Cities. This will both contribute to the global distribution and resource allocation of China's culture industry, and benefit the construction of mutually beneficial and cooperative international culture industry communities, so the countries and people of the Belt and Road regions can share their cultural wealth.

Fouimba and Goma Mounts Greenstone Belts Litho-Structural Analysis Related to Côte D’Ivoire Birimian Geodynamic Setting and Implying in West-Africa Craton Gold Deposits

Mount Fouimba and Mount Goma (Seguela) greenstone belts petro-structural studies combine remote sensing, geophysics, petrography and structural analysis. In view of establishing mapping details of paleoproterozoic geological formations, geological setting rocks observed are essentially magmatic formations, such as two-mica granite, granodiorites, and porphyritic basalts;and a few metamorphics which are metatonalite, amphibolites and amphibo-lopyroxenites. Remote sensing, such as Landsat 8 OLI satellite imagery and geophysical data, has been combined to show regional NNE-SW shear zone. Tectonic structures and microstructures have enabled to identify two main deformation phases: D1 phase corresponding to compression, and D2 is a transpression phase. Mechanisms responsible for deformations are respectively flattening and transpression. Geological formations derived from mantle origin but contain crustal components, and their tectonic setting occurred during subduction.

Insight from Lithostructural and Aeromagnetic Data from the Léo Square Degree, Central-Western Burkina Faso

This study, carried out in the Léo square degree (west-central Burkina Faso) in the Palaeoproterozoic domain of the Man/Léo ridge, aims to define the shapes and positions of granitic plutons and the organisation of deformation structures using aeromagnetic data. These data have shown that there are small sub-circular granitic bodies to the north of the granitic masses in this region, and a large sub-circular granitic body to the south, around which are other smaller granitic bodies. The lineament map shows that the deformation structures are organised along three main directions and largely form these sub-circular plutonic bodies. We suggest that the granitic plutons are coalescent, pending identification of the internal structures of these granites to further refine the geodynamic model.

北山造山带东部微波山早志留世S型花岗岩成因及构造背景

为研究北山造山带东部微波山地区的大地构造背景,选取在该地区广泛发育的花岗岩为研究对象,通过野外地质工作、锆石U-Pb年代学、岩石学及地球化学等研究方法,深入剖析了微波山花岗岩的形成时代、类型、成因及构造背景。锆石年龄为(440.80±0.19)Ma和(155.05±0.37)Ma,表明该岩体形成于早志留世,并在侏罗世形成复式岩体。岩石学特征定名本次样品为二长花岗岩,地球化学特征显示成因类型为S型花岗岩,稀土配分曲线与微量元素蛛网图为右倾型,显示岛弧岩浆岩特征。根据Yb、Y、Sr、Al_(2)O_(3)的含量特征确定其中两个样品为埃达克岩,建立微波山构造-岩浆演化模型,早志留世小黄山洋盆向北俯冲,幔源岩浆底侵,长英质岩浆移出形成岛弧岩浆岩。

2023年12月2日芒市M_(S)5.0地震前地震活动异常

总结2023年12月2日云南芒市M_(S)5.0地震发生前地震活动异常,发现震前存在中期、短期和临震异常。其中:(1)中期阶段:滇西地区M≥5.0地震存在东西迁移规律,且M_(L)≥4.0地震活动具有由滇西北向小滇西迁移的特点;(2)中短期阶段:小滇西地区中小地震活动显著增强,3、4级地震围成孕震空区并伴随出现M_(L)≥3.0地震条带;(3)短期阶段:出现逼近地震和前兆震群,临震前10天发生前震。分析认为,“逼近地震”和前兆震群的发生,是地震孕育过程从中期转入短临阶段的拐点。

大别造山带地壳S波速度结构

在大别造山带深地震测深剖面H维P波地壳速度结构的基础上,从地震记录的水平分量得到S波地壳速度结构,并用P波和S波的资料共同约束地壳的组成.剖面上大多数炮点的记录均显示了清晰的Sg和SmS震相.在埠塔寺炮和金拱炮的记录上还较清晰地显示出莫霍界面的反射转换震相PmS,表明在相应的范围内莫霍界面是一级间断面.在Pn和SmS震相都比较强的记录截面图上缺少相应的Sn震相,表示在上地幄顶部泊松比随深度急剧增大,在这一深度上物质可能存在局部熔融状态.剖面的地壳泊松比模型表明,上地壳在深度10km以内泊松比为025左右,仅北淮阳弧后复理石带较低,为0.23；扬子板块和华北板块的下地壳泊松比为0.26-0.27；在大别选山带,上地壳下部泊松比为0.22-0.24,而下地壳泊松比为0.27-0.30,其中超高压变质带最高.P、S波速度和泪松比表明超高压变质带下地壳主要由基性麻粒岩组成.大别造山带中、下地壳组成的横向不均匀性反映了在三叠纪造山作用期间扬子板块向华北板块俯冲,以及存在与地慢物质相联系的岩浆侵入体.