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Based on panel data from 210 prefecture-level cities in China from 2003 to 2021, this study employs the Time-Varying Differences-in-Differences (Time-Varying DID) approach to systematically examine the impact of smart city construction on pollution emissions and its underlying mechanisms. Additionally, the Propensity Score Matching–Differences-in-Differences method is employed for further validation. The research findings indicate that Smart City Construction (SCC) significantly reduces urban Volume of Sewage Discharge (VSD), sulfur dioxide emissions (SO2), and Emissions of Fumes and Dust (EFD), thereby mitigating pollution emissions (PE) and enhancing environmental quality. Mechanism analysis reveals that SCC achieves these effects through scale effects, structural effects, and technological effects. City heterogeneity analysis shows that provincial capital cities exhibit a stronger suppression effect on pollution emissions compared to non-provincial capital cities. Moreover, cities with lower levels of education attainment demonstrate a stronger ability to curb pollution emissions, while larger cities exhibit a more pronounced impact on mitigating pollution emissions. The marginal contributions of this study mainly consist of three aspects: Firstly, it enriches the literature on environmental impact factors by assessing, for the first time, the influence of SCC on PE. Secondly, a comprehensive approach is employed, integrating VSD, EFD, SO2 data, and economic and pollution data at the city level. Time-Varying DID is used to evaluate the policy effects of SCC. Finally, the study analyzes the impact mechanisms of SCC policy on environmental emissions from various perspectives. [ABSTRACT FROM AUTHOR]

Background: The aims of the study were to evaluate potential differences among first-line treatment for EGFR mutant (m+) non-small cell lung cancer (NSCLC) patients with brain metastasis in China and to identify the factors influencing survival outcomes. Methods: In this retrospective study, 172 EGFRm + patients with advanced NSCLC who received a 1st generation EGFR tyrosine kinase inhibitor (TKI) were divided into 4 groups: A, EGFR-TKI (n = 84); B, EGFR-TKI + pemetrexed + cisplatin/carboplatin chemotherapy (CT) (n = 55); C, EGFR-TKI + bevacizumab (n = 15); and D, EGFR-TKI + pemetrexed + cisplatin/carboplatin CT + bevacizumab (n = 18). Intracranial and extracranial progression-free survival (PFS), the overall survival (OS), objective remission rates (ORRs) and adverse events were analyzed. Results: Intracranial PFS of groups C + D was longer than for groups A + B (18.9 m vs. 11.0 m, P = 0.027). Extracranial PFS were longer in group B in comparison with group A (13.0 m vs. 11.5 m, P = 0.039) and in groups C + D compared to groups A + B (18.9 m vs. 11.9 m, P = 0.008). Median OS in groups A and B were 27.9 m and 24.4 m, respectively, while groups C and D have not yet achieved median OS. Significant difference was found in intracranial ORR between groups A + B vs. C + D (31.0% vs. 65.2%, P = 0.002). Most patients suffered grade 1–2 treatment-related adverse events, which were relieved soon after symptomatic treatment. Conclusions: First-generation EGFR-TKI + bevacizumab treatment outperformed other regimens in EGFRm + NSCLC patients with brain metastasis. The therapy improved the control and delayed progression of intracranial lesions and prolonged survival times. [ABSTRACT FROM AUTHOR]

Stroke has become a major cause of death and disability worldwide. The cellular recycling pathway autophagy has been implicated in ischemia-induced neuronal changes, but whether autophagy plays a beneficial or detrimental role is controversial. Hydroxysafflor Yellow A (HSYA), a popular herbal medicine, is an extract of Carthamus tinctorius and is used to treat ischemic stroke (IS) in China. HSYA has been shown to prevent cardiovascular and cerebral ischemia/reperfusion injury in animal models. However, the specific active ingredients and molecular mechanisms of HSYA in IS remain unclear. Here, we investigated the effect of HSYA treatment on autophagy in a rat model of IS. IS was induced in rats by middle cerebral artery occlusion. Rats were treated once daily for 3 days with saline, HYSA, or the neuroprotective agent Edaravone. Neurobehavioral testing was performed on days 1, 2, and 3 post-surgery. Brains were removed on day 3 post-surgery for histological evaluation of infarct area, morphology, and for qRT-PCR and western blot analysis of the expression of the autophagy factor LC3 and the signaling molecules HIF-1 α , BNIP3, and Notch1. Molecular docking studies were performed in silico to predict potential interactions between HSYA and LC3, HIF-1 α , BNIP3, and Notch1 proteins. The result showed that HSYA treatment markedly alleviated IS-induced neurobehavioral deficits and reduced brain infarct area and tissue damage. HSYA also significantly reduced hippocampal expression levels of LC3, HIF-1 α , BNIP3, and Notch1. The beneficial effect of HSYA was generally superior to that of Edaravone. Molecular modeling suggested that HSYA may bind strongly to HIF-1 α , BNIP3, and Notch1 but weakly to LC3. In conclusion, HSYA inhibits post-IS autophagy induction in the brain, possibly by suppressing HIF-1 α , BNIP3 and Notch1. HSYA may have utility as a post-IS neuroprotective agent. [ABSTRACT FROM AUTHOR]

Objectives: To explore the role of folate metabolism in 1,3-Butadiene (BD)'s genotoxicity, we conducted a match-up study in BD-exposed workers in China to analyze the associations between the polymorphisms of methylenetetrahydrofolate reductase (MTHFR) and the chromosomal damage induced by BD exposure, and culture-based experiments in TK-6 cells to examine the global DNA methylation levels and chromosomal damage when exposed both to BD's genotoxic metabolite, 1,2:3,4-diepoxybutane (DEB), and MTHFR's direct catalytic product, 5-methyltetrahydrofolate (5-MTHF). Methods: Cytokinesis block micronucleus assay (CBMN) was used to examine the chromosomal damage induced by BD or DEB. Poisson regression models were produced to quantify the relationship of chromosomal damage and genetic polymorphisms in the BD-exposed workers. Global DNA methylation levels in TK6 cells were examined using DNA Methylation Quantification Kit. Results: We found that BD-exposed workers carrying MTHFR C677T CC (2.00 ± 2.00‰) (FR = 0.36, 95%CI: 0.20–0.67, P < 0.01) or MTHFR C677T CT (2.87 ± 1.98‰) (FR = 0.49, 95%CI: 0.32–0.77, P < 0.01) genotypes had significantly lower nuclear bud (NBUD) frequencies than those carrying genotype MTHFR 677 TT (5.33 ± 2.60‰), respectively. The results in TK6 cells showed that there was a significant increment in frequencies of micronucleus (MN), nucleoplasmic bridge (NPB) and nuclear bud (NBUD) with exposure to DEB at each 5-MTHF dose (ANOVA, P < 0.01). Additionally, there was a significant decrease in frequencies of MN, NPB and NBUD in DEB-exposed cultures with increasing concentration of 5-MTHF (ANOVA, P < 0.05). The levels of global DNA methylation were significantly decreased by DEB treatment in a dose-dependent manner within each 5-MTHF concentration in TK-6 cells (ANOVA, P < 0.01), and were significantly increased by 5-MTHF supplementation within each DEB concentration (ANOVA, P < 0.01). Conclusion: We reported that folate metabolism could modify the association between BD exposure and chromosomal damage, and such effect may be partially mediated by DNA hypomethylation, and 5-MTHF supplementation could rescue it. [ABSTRACT FROM AUTHOR]

Internal structures of the pluton may provide key information on magma emplacement mechanism and the relationship with regional tectonics. We present a case study on the Late Triassic Gaoqiao pluton from South Qinling Belt, which was emplaced under a syn‐collisional setting. Multi‐approaches including zircon U–Pb geochronology, field and microstructural observations, anisotropy of magnetic susceptibility analysis was conducted to reconstruct the growth process of the pluton and to investigate the internal structures. Zircon U–Pb geochronology reveals that the pluton is a composite intrusion which was constructed by two successive units with distinct ages (~220 and ~210 Ma). Field observations show that the Gaoqiao pluton and its country rocks recorded abundant evidences of syn‐plutonic deformations, indicating a syn‐tectonic emplacement. Microstructural observations show that the internal fabrics were mainly acquired during the stage from magma flow to high‐T solid‐state deformation. The fabric distributions display 'onion‐skin' patterns on the pluton scale, which are characterized by zoned foliations and lineations. Combined with the syn‐collisional convergence setting, we propose a tectonic‐controlled incremental growth model for the pluton, in which the pluton was successively constructed by the Fujiahe unit and the Hetaoping unit, and the emplacement process of the pluton was controlled by the regional deformation with sinistral transpressional kinematics. Furthermore, the internal fabric patterns of the Gaoqiao pluton were probably formed by tectonic‐controlled helical magma flow, which appears to be common in fabric formation of many other plutons with similar features. [ABSTRACT FROM AUTHOR]

This study aims to observe the clinical characteristics of recovered patients from Coronavirus Disease 2019 (COVID‐19) with positive in reverse transcription‐polymerase chain reaction (RT‐PCR) or serum antibody. The profile, clinical symptoms, laboratory outcomes, and radiologic assessments were extracted on 11 patients, who tested positive for COVID‐19 with RT‐PCR or serum antibody after discharged and was admitted to Hubei No. 3 People's Hospital of Jianghan University for a second treatment in March 2020. The average interval time between the first discharge and the second admission measured 16.00 ± 7.14 days, ranging from 6 to 27 days. In the second hospitalization, one patient was positive for RT‐PCR and serum antibody immunoglobulin M (IgM)‐immunoglobulin G (IgG), five patients were positive for both IgM and IgG but negative for RT‐PCR. Three patients were positive for both RT‐PCR and IgG but negative for IgM. The main symptoms were cough (54.55%), fever (27.27%), and feeble (27.27%) in the second hospitalization. Compared with the first hospitalization, there were significant decreases in gastrointestinal symptoms (5 vs 0, P =.035), elevated levels of both white blood cell count (P =.036) and lymphocyte count (P =.002), remarkedly decreases in C‐reactive protein and serum amyloid A (P <.05) in the second hospitalization. Additionally, six patients' chest computed tomography (CT) exhibited notable improvements in acute exudative lesions. There could be positive results for RT‐PCR analysis or serum IgM‐IgG in discharged patients, even with mild clinical symptoms, however, their laboratory outcomes and chest CT images would not indicate the on‐going development in those patients. [ABSTRACT FROM AUTHOR]

This paper aims at exploring the tectonic characteristics of the South China Continent (SCC) and extracting the universal tectonic rules from these characteristics, to help enrich the plate tectonic theory and better understand the continental dynamic system. For this purpose, here we conduct a multi-disciplinary investigation and combine it with the previous studies to reassess the tectonics and evolution of SCC and propose that the tectonic framework of the continent comprises two blocks, three types of tectonic units, four deformation systems, and four evolutionary stages with distinctive mechanism and tectonic characteristics since the Neoproterozoic. The four evolutionary stages are: (1) The amalgamation and break-up of the Neoproterozoic plates, typically the intracontinental rifting. (2) The early Paleozoic and Mesozoic intracontinental orogeny confined by plate tectonics, forming two composite tectonic domains. (3) The parallel operation of the Yangtze cratonization and intracontinental orogeny, and multi-phase reactivation of the Yangtze craton. (4) The association and differentiation evolution of plate tectonics and intracontinental tectonics, and the dynamic characteristics under the Meso-Cenozoic modern global plate tectonic regime. [ABSTRACT FROM AUTHOR]

The Zhongchuan district is an important component of the metallogenic belt in the Western Qinling. The Zhongchuan granite pluton occurring in the centre of the Zhongchuan metallogenic area has been poorly constrained, though the Triassic granite in Western Qinling has been well documented. In-situ zircon U-Pb ages, Hf isotopic compositions and whole-rock geochemical data are presented for host granite and mafic microgranular enclaves (MMES) from the Zhongchuan pluton, in order to constrain its sources, petrogenesis and tectonic setting of the pluton. The distribution of major, trace and rare earth elements apparently reflect exchange between the MMES and the host granitic rocks mainly due to interactions between coeval felsic host magma and mafic magma. The zircon U-Pb age of host granite (231.6 ± 1.5 to 235.8 ± 2.3 Ma) has overlapping uncertainty with that of the MMES (236.6 ± 1.3 Ma), establishing that the mafic and felsic magmas were coeval. The Hf isotopic composition of the MMES ( εHf( t) = −13.4 to 4.0) is distinct from the host granite ( εHf( t) = −15.7 to 0.0), indicating that both enriched subcontinental lithosphere mantle (SCLM) and crustal sources contributed to their origin. The zircons have two-stage Hf model ages of 1064 to 1798 Ma for the host granite and 858 to 1747 Ma for the MMES. This suggests that the granitic pluton was likely derived from partial melting of a Late Mesoproterozoic crust, with subsequent interaction with the SCLM-derived mafic magmas in tectonic affinity to the South China Block. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: The Phanerozoic tectonic regimes of the South China Block (SCB) hold a key to understanding of its geodynamic evolution with respect to formation of numerous mineral resources. Despite long-time debates in the past three decades, there is still no consensus on the two key points whether the Phanerozoic tectonothermal events were due to subduction of the Pacific plate or intracontinental reworking and whether the three periods of tectonothermal events in the middle Paleozoic (Kwangsian), Triassic (Indosinian) and Jurassic–Cretaceous (Yanshanian) are mainly driven by tectonic transition in subduction of the oceanic crust from Paleotethyan in the west to Pacific in the east. This paper presents an overview of key geological observations in the SCB with respect to its Phanerozoic tectonics. Available data show that there are distinctive sedimentary, magmatic, structural and metamorphic records across the Xuefeng-Jiangnan Domain in the SCB. The geological signatures associated with the Kwangsian and Indosinian tectonothermal events are predominantly preserved in the eastern SCB, including the eastern Yangtze and Cathaysia Blocks to the east of the Xuefeng-Jiangnan Domain. They are characterized by strong thrusting/transpression, anatexic granitic magmatism, high-grade metamorphism and the poor involvement of the juvenile mantle-derived rocks. The two events were dated at ca. 400–460Ma and ca. 200–250Ma, respectively. The Yanshanian tectonothermal event is dominantly represented by the development of a wide magmatic belt of exceeding 1300km (from the coastal province to the Xuefeng-Jiangnan Domain) and a broad deformational belt of more than 2000km (from the coastal province to the Sichuan basin). The Yanshanian I-, S- and A-type granites, syenite and volcanic rocks display two arrays, which are oblique and parallel to the coastal provinces of the southeast China, respectively. They were mainly formed at the three age-spans of 152–180Ma, 120–130 and 87–107Ma with the peak of 158Ma, 125Ma and 93Ma, respectively. The stillstand time of the Yanshanian magmatism was temporally overlapped by the deformation time of the top-to-the-NW progressive transpression or sinistral strike-slip at 132–142Ma and 95–112Ma, respectively. In conjunction with the observations and controversies, a geodynamic model is proposed for the Mesozoic tectonic evolution of the SCB. [Copyright &y& Elsevier]

The Dabie orogen underwent deep continental subduction, rapid exhumation, and the huge amount of erosion during the Mesozoic. Its tectonic evolution, especially how its evolution was recorded by sedimentary basins at the flanks of the Dabie orogen is one of the most important issues of the world's attention. These years, newly studies of basin sedimentology, combined with structural geology, have shown a fundamental progress. The overall distribution of different basin types in the orogen indicates that shortening and thrusting at the margins of the orogen from the Late Triassic to the Early Cretaceous controlled the foreland basins, and extension, doming and rifting were initiated in the core of the orogen from the Jurassic to the Early Cretaceous and were expanded to the whole orogen after the Late Cretaceous. Therefore, The Dabie orogen records gradual transition from overall shortening and thrusting to dominantly extension and rift basin formation expanded from its core to its margins, although these shortening and extension overlapped in time from the Jurassic through Early Cretaceous at crustal levels. The unroofing ages of the ultra-high pressure (UHP) metamorphic rocks in the Dabie orogen change from Early Jurassic to Late Jurassic westward. The depth of exhumation increases eastwards. The sediment sources for the Hefei basin are mostly composed of the deeply exhumed, axial Dabie metamorphic complex, and the sediment sources for the Middle Yangtze basin are mostly from cover strata in the southern orogen and related strata with subjacent (i.e. subsequently overthrusted) Mianlue suture belt. Geodynamic analysis represents that continental collision between the North China Block and the South China Block along the Shangdan and Mianlue sutures, subsequently northwestward progradation of the Jiangnan fold and thrust belt, and the underthrusting of the North China Block along the Northern Boundary Fault of Qinling Range led to crustal thickening, gravitational spreading and balanced rebound of the resultant thick crustal welt, and multi-episodic exhumation of the HP/UHP metamorphic rocks. The future studies by the methods of tracing the Dabie orogeny through deposition in the marginal basins should focus on eastward extension of the Mianlue suture, thrust and overlap of the Dabie HP/UHP metamorphic block on different lithotectonic zones and basins along the northern South China Block, the structural framework of the source area of the basins in the syn-depositional stage, the basin lateral extension, huge amount of erosion and sediment transportation from the Dabie blanket and basement rocks, and recovery of subducted and removed structural units within the Dabie orogen, etc. [ABSTRACT FROM AUTHOR]

The Xunhua, Guide and Tongren intermontane basin system in the NE Tibetan Plateau, situated near the Xining basin to the N and the Linxia basin to the E, is bounded by thrust fault-controlled ranges. These include to the N, the Riyue Shan, Laji Shan and Jishi Shan ranges, and to the S the northern West Qinling Shan ( NWQ). An integrated study of the structural geology, sedimentology and provenance of the Cenozoic Xunhua and Guide basins provides a detailed record of the growth of the NE Tibetan Plateau since the early Eocene. The Xining Group ( ca. 52-21 Ma) is interpreted as consisting of unified foreland basin deposits which were controlled by the bounding thrust belt of the NWQ. The Xunhua, Guide and Xining subbasins were interconnected prior to later uplift and damming by the Laji Shan and Jishi Shan ranges. Their sediment source, the NWQ, is constrained by strong unidirectional paleocurrent trends towards the N, a northward fining lithology, distinct and recognizable clast types and detrital zircon ages. Collectively, formation of this mountain-basin system indicates that the Tibetan Plateau expanded into the NWQ at a time roughly coinciding with Eocene to earliest Miocene continental collision between India and Eurasia. The Guide Group ( ca. 21-1.8 Ma) is inferred to have been deposited in the separate Xunhua, Guide and Tongren broken foreland basins. Each basin was filled by locally sourced alluvial fans, braided streams and deltaic-lacustrine systems. Structural, paleogeographic, paleocurrent and provenance data indicate that thrust faulting in the NWQ stepped northward to the Laji Shan from ca. 21 to 16 Ma. This northward shift was accompanied by E-W shortening related to nearly N-S-striking thrust faulting in Jishi Shan after 11-13 Ma. A lower Pleistocene conglomerate (1.8-1.7 Ma) was deposited by a through-flowing river system in the overfilled and connected Guide and Xunhua basins following the termination of thrust activity. All of the basin-mountain zones developed along the Tibetan Plateau's NE margin since Indian- Tibetan continental collision may have been driven by collision-induced basal drag of old slab remnants in the manner of N-dipping and flat-slab subduction, and their subsequent sinking into the deep mantle. [ABSTRACT FROM AUTHOR]

Summary: Most of the coal mines of China are mining under the ground, so the artesian test which is one of the aquifer tests is conducted normally several hundred of meters below the earth surface. And the target aquifer is with very high hydraulic pressure, sometimes more than 3MPa. Because of the high hydraulic pressure, it is most difficult to control the rate of flow out of the artesian well. Moreover, the velocity of flow out of the well cannot descend rapidly to zero, thus the analytical solution of Jacob and Lohman type curve for the artesian test will not be applicable. It is more reasonable if analyzing this test as a pumping test but with variable discharge. It is considered to rebuild that hydrogeological conceptual model in this paper. This conceptual model is similar with Theis model but with the variable discharge merely. And a general equation for any discharge variability is given. Its application for the linearly decreasing discharge is presented subsequently, and a type curve of this equation with linearly decreasing discharge will be given as well. Then a simple numerical model using FEFLOW will be built to simulate the linearly decreasing discharge from giving several different groups of the values of Transmissivity (T) and Storage coefficient (S). Both of them are much important hydrogeological parameters, and will be evaluated by using the type curve developed for this linear decreasing discharge well. The error between the given values of T and S in FEFLOW and the values of those calculated by matching point are much small. The solution gives really satisfactory values of these hydrogeological parameters. [ABSTRACT FROM AUTHOR]

The Liziyuan gold deposit, located on the northern margin of the western Qinling orogen (WQO), consists of five mineralized sites hosted by metavolcanic rocks, and one hosted by the Tianzishan monzogranite. Orebodies mainly occur as lenticular veins along NW-striking dextral ductile strike–slip shear zones. Major wall rock alteration includes silicification, pyritization, and carbonation, progressively increasing in intensity towards the orebodies. Ore minerals are dominated by pyrite, galena, and chalcopyrite; the major gangue minerals are quartz and calcite. Native gold is present chiefly as separate phases in sulphide and quartz microfractures. We recognize four stages of mineralization: (I) pyrite-quartz, (II) native gold-chalcopyrite-pyrite-quartz, (III) pyrite-freibergite-galena-quartz-carbonate, and (IV) carbonate stages. Fluid inclusion petrography and microthermometric results suggest that three types of primary fluid inclusions (carbonic, CO2–H2O, and aqueous) are present in the deposit. Microthermometric data and Laser Raman analyses indicate that the ores were deposited from moderate temperature (240–280°C), low salinity (0.5–9.1 wt.% NaCl equiv.) H2O–NaCl–CO2–(CH4) fluids. The common coexistence of aqueous, CO2–H2O, and carbonic inclusions indicates the trapping of heterogeneous immiscible fluids. Trace elements in mineralized quartz and carbonate veins suggest that the ore-forming fluids were mainly produced by prograde metamorphism of the upper crust. The calculated and δD values are 1.8–3.8‰ and –77‰ to –75‰, respectively, for quartz from stage II and –8.5‰ to –6.6‰ and –72‰ to –71‰ for calcite from stage III, implying that the ore-forming fluids were metamorphic in origin and evolved by late-stage mixing with meteoric water. Pyrite and galena have δ34S values of 3.9–8.5‰ with a pronounced mode at 5–8‰. Such relatively homogeneous sulphur isotopic compositions are consistent with orogenic gold deposits throughout the world, indicating that the sulphur was mainly sourced from reduced metamorphic fluids. The Liziyuan gold deposit can be grouped with other orogenic gold deposits that have similar characteristics. Geological observations and available isotopic ages suggest that the Liziyuan lode mineralization was related to the Indosinian orogenesis of the Qinling belt. Triassic continental collision caused crustal thickening, dextral ductile shearing, and greenschist facies metamorphism throughout the orogen. Due to the intensive deformation and metamorphism, crustal rocks released copious fluids that evidently mobilized and extracted ore elements along their flow pathways. The ductile shear zone in the Liziyuan mining area provided regions of low mean stress and high permeability, and thus appeared to be preferential channels for precipitation of the ore-forming fluids. As highly charged fluids migrated into the high permeability shear zones, rapid changes in physicochemical conditions resulted in sulphide precipitation and gold mineralization. [ABSTRACT FROM PUBLISHER]

Abstract: The eastern part of the Central Tianshan Belt in China is characterized by abundant granitoids, which are not only indicators of the interaction between crust and mantle but also can be used for tracking the tectonic evolutionary history of the orogen. Four granitic plutons, muscovite granites (MG), biotite monzonitic granites (BMG), biotite granites (BG), and alkali granites (AG), have been recognized to have intruded in the Mishigou area, Central Tianshan Belt. The MG has pronounced a S-type affinity, which is strongly peraluminous with a high aluminum saturation index, and displays positive Rb, Th, U and LREE anomalies with a strong negative Ba, Nb, Sr, P, Ti and Eu anomalies. Therefore, the magma of the MG is considered to have been derived from melting of thickened continental crust, which is composed mainly of the sediments eroded from a pre-Silurian continental island-arc. The U–Pb zircon age of 424.5±2.6Ma constrains the age of MG and crust thickening. The BG and BMG granitoids display I-type geochemical features and have affinities to subduction arcs. Both of them are characterized by calc-alkaline peraluminous granites with a significant LREE enrichment and a negative Eu anomaly, as well as a depletion in Ba, Nb, Ta, Sr, P and Ti and an enrichment in Rb, Th, U, Nd, Zr and Sm. These characteristics indicate that they were derived from a mixed magma source between lower continental crust and the input of components derived from the mantle wedge above the subduction zone. The LA-ICPMS zircon U–Pb ages of 411±4.7Ma and 402±3.4Ma represent the formation ages of the BG and BMG granitoids, respectively, which also constrain that the subduction of the South Tianshan oceanic crust also occurred during Early Devonian time. The AG shows a typical A-type granite affinity with depletion of Nb, Ta, Sr, P, Ti and Y. It is interpreted that AG was formed in a within-plate tectonic setting, and related to continental up-doming and rifting zones as a consequence of the extensional collapse after the collision of the Tianshan orogen. The U–Pb zircon age of 290±5.1Ma represents the formation age of the AG, and the time of the extensional collapse and rifting. [Copyright &y& Elsevier]

A paleomagnetic study was carried out on late Jurassic sediments in the Nanjing area. Stepwise thermal demagnetization was used to isolate the characteristic higher temperature component (HTC) (D=354.0°, I=48.5°, a95=7.8°), which passes the reversal test. A 24.7 ± 8.7°counter-clockwise rotation relative to the Sichuan area is detected through comparing this new pole (84.4°N, 7.0°E, A95=7.7°) with other coeval poles reported from South China. This rotation was conducted by sinistral action of slip faults. These cases presenting in several areas of eastern China indicate that deformation of eastern China is under the effect of subduction from the Pacific Ocean plate. The difference on the paleolatitude of several areas across the Tan-Lu fault zone is calculated and suggests about at most 250 km offset distance after the later Jurassic. [ABSTRACT FROM AUTHOR]

Abstract: A kinematic and geochronological study has been carried out on the Triassic high-strain shear zones in Hainan Island, the southern South China Block. There are WNW- and NE-trending high-strain shear zones with greenschist- to amphibolite-facies metamorphism in this island. Kinematic indicators suggest a dextral top-to-the-NNE thrust shearing for the WNW-trending high-strain shear zones and a sinistral top-to-the-SE thrust shearing for the NE-trending shear zones. The quartz c-axis orientations of mylonitic rocks exhibit the domination of basal slip and some activation of a rhombohedra gliding system. The timing of shearing for these shear zones has been constrained by the 40Ar/39Ar dating analyses of synkinematic minerals. Middle Triassic (242–250Ma) and late Triassic–early Jurassic (190–230Ma) have been identified for the WNW- and NE-trending shear zones, respectively. A synthesis of these kinematic and thermogeochronological data points to a two-stage tectonic model for Hainan Island, that is, top-to-the-NNE oblique thrusting at 240–250Ma followed by top-to-the-SE oblique thrusting at 190–230Ma. In combination with the available data from the southern South China and Indochina Blocks, it is inferred that South Hainan and North Hainan have affinity to the Indochina and South China Blocks, respectively. The tectonic boundary between South Hainan and North Hainan lies roughly along the WNW-trending Changjiang–Qionghai tectonic zone probably linking to the Song Ma and Ailaoshan zones. The middle Triassic structural pattern of Hainan Island is spatially and temporally compatible with those of the South China and Indochina Blocks, and thus might be a derivation from the amalgamation of the Indochina with South China Blocks in response to the closure of the Paleotethys Ocean and subsequent subduction/collision. [Copyright &y& Elsevier]

Abstract: The amphibolite facies grade North Qinling metamorphic unit forms the centre of the Qinling orogenic belt. Results of LA-ICP-MS U-Pb zircon, 40Ar/39Ar amphibole and biotite dating reveal its Palaeozoic tectonic history. U-Pb zircon dating of migmatitic orthogneiss and granite dykes constrains the age of two possible stages of migmatization at 517±14Ma and 445±4.6Ma. A subsequent granite intrusion occurred at 417±1.6Ma. The 40Ar/39Ar plateau ages of amphibole ranging from 397±33Ma to 432±3.4Ma constrain the cooling of the Qinling complex below ca. 540°C and biotite 40Ar/39Ar ages at about 330–368Ma below ca. 300°C. The ages are used to construct a cooling history with slow/non-exhumation during 517– 445Ma, a time-integrated cooling at a rate <2.5°C/Ma during the period of 445–410Ma, an acceleration of cooling at a rate of 8°C/Ma from 397Ma to 368Ma, and subsequently slow/non-cooling from 368 to 330Ma. The data show a significant delay in exhumation after peak metamorphic conditions and a long period of tectonic quiescence after the suturing of the North China and South China blocks along the Shangdan suture. These relationships exclude classical exhumation models of formation and exhumation of metamorphic cores in orogens, which all imply rapid cooling after peak conditions of metamorphism. [Copyright &y& Elsevier]

Abstract: This contribution reviews the tectonic structure and evolution of the Qinling orogenic belt, which extends east–west nearly 2500km across Central China and is a giant orogenic belt formed by the convergence and collision between North China and South China Blocks. The principal tectonic elements including metamorphic basement and its Neoproterozoic to Triassic cover, ophiolitic sutures, nature and ages of granitoid belts, provenance studies and tectonometamorphic studies of metamorphic belts allow tracing the polarity of two stages of plate convergence and collision and the further tectonic history. In this review, we present new distribution maps of the Early Paleozoic ophiolites and associated volcanics in the Shangdan suture zone and the Middle Devonian–Middle Triassic ophiolitic melange in the Mianlue suture zone, as well as the maps of granitoid and metamorphic belts displaying various ages (Silurian–Devonian, Triassic, Late Jurassic–Early Cretaceous). These maps allow better constrain the polarity of subduction and collision. We also discuss the significance of the Early Cretaceous Yanshanian events, which represent a linkage between tectonic events in the Tethyan and East China/Pacific realms. Two ophiolitic sutures, the Shangdan suture zone in the north and the Mianlue suture in the south, have been intensively studied during the past two decades. The Qinling Orogen is divided into the North Qinling and the South Qinling Belts by the Shangdan suture zone, and this suture zone is thought to represent the major suture separating the North China and South China Blocks. However, the timing and processes of convergence between these two blocks have been disputed for many years, and Silurian–Devonian or Late Triassic collision has been proposed as well. Based on the recent results, a detailed convergent evolutionary history between the North China and South China Blocks along the Shangdan suture is here proposed. The Mianlue suture zone is well documented and represents the Mianlue ocean which separates the South Qinling from the South China Block in Devonian to Mid Triassic times. After the closure of the Mianlue ocean, the South Qinling Belt was emplaced onto the Yangtze Block along the Middle Triassic Mianlue suture zone in Late Triassic–Jurassic times. This suture was overprinted by the south-directed overthrust of the Mianlue–Bashan–Xiangguang thrust fault operative in Late Jurassic-Cretaceous times. Furthermore, we note that the Yanshanian tectonic events play a major role for rapid Early Cretaceous exhumation of significant portions of the Qinling orogenic belt. In contrast, although high topographic gradients, the Cenozoic tectonism related to lateral extrusion of the Tibet plateau resulted in minor and continuous exhumation and erosion along major transtensional and strike-slip faults were activated. [Copyright &y& Elsevier]

Abstract: The tectonic framework and the evolutionary history of the Qinling orogenic belt are keys for understanding the convergent processes between the North China and South China blocks. The widely exposed ophiolitic and subduction-related volcanic melange along the Shangdan and Erlangping belts provides important constraints on the tectonic evolutionary processes of the Qinling orogen. The melange in the Shangdan zone is predominantly composed of ultramafic and mafic rocks that can be divided into three geochemical groups: (1) N- MORB type; (2) E-MORB type; and (3) island-arc/active continental margin-related basalts. The samples with N- and E-MORB affinity are characterized by depletion or slight enrichment of LREE without fractionation of HFSE and no negative Nb–Ta anomaly. The island-arc/active continental margin-related basalts are typically depleted in Nb–Ta and Ti. It is inferred that the melange within the Shangdan suture represents remnants of an oceanic crust and associated volcanics. An age for the melange can be constrained by a U–Pb zircon age of 517.8±2.8Ma, obtained from the gabbro within the E-MORB-type ophiolite in the Yanwan area. To the north of the suture zone, the Erlangping melange consists similarly of ultramafic and mafic rocks, andesites and rhyolites. The mafic and andesitic rocks exhibit strong depletion of Nb–Ta and Ti indicating a subduction-related affinity. However, their depletion in Nb–Ta is weaker than that of the island-arc/active continental margin-related volcanic rocks. Taken together, the two ophiolitic melange zones indicate the existence of an early Palaeozoic Shangdan Ocean that was associated with a back-arc basin on the northern North Qinling Island arc terrane, separating the South China from the North China blocks. [ABSTRACT FROM AUTHOR]

Abstract: The Trans-North China Orogen separates the North China Craton into two small continental blocks: the Eastern and Western Blocks. As one of the largest exposure in the central part of the orogen, the Hengshan–Wutai–Fuping Complexes consist of four lithotectonic units: the Wutai, Hengshan and Fuping Complexes and the Hutuo Group. The Hengshan Complex contains high pressure mafic granulites and retrograded eclogites. Structural analysis indicates that most of the rocks in these complexes underwent three distinct episodes of folding (D1 to D3) and two stages of ductile thrust shearing (STZ1 between D1 and D2 and STZ2 after D3). The D1 deformation formed penetrative axial planar foliations (S1), mineral stretching lineations (L1), and rarely-preserved small isoclinal folds (F1) in the Hengshan and Fuping Complexes. In the Wutai Complex, however, large-scale F1 recumbent folds with SW-vergence are displayed by sedimentary compositional layers. Penetrative transposition resulted in stacking of thrust sheets which are separated by ductile shear zones (STZ1). The kinematic indicators of STZ1 in the Hengshan and Wutai Complexes show top-to-the-S230°W thrusting likely related to northeastward, oblique pre-collisional subduction. D1 resulted in crustal thickening with resultant prograde peak metamorphism. The Hutuo Group did not undergo the D1 deformation, either because sedimentation was coeval with the D1 deformation or because it was at a high structural level and was not influenced directly by the early deformation. The D2 deformation produced NW-verging asymmetric and recumbent folds. The D2 deformation is interpreted to have resulted from collision between the Eastern and Western Blocks of the North China Craton. In the Hutuo Group and the Fuping Complex, the development of ESE-verging asymmetric tight folds is associated with D2. The structural pattern resulting from superimposition of D1 and D2 is a composite synform in the Hengshan–Wutai–Fuping Complexes. All four lithotectonic units were superposed during the later D3 deformation. The D3 deformation developed NW-trending open upright folds. Ongoing collision led to development of transpressional ductile shearing (STZ2), forming the transpressional Zhujiafang dextral ductile shear zone between the northern Hengshan Complex and the southern Hengshan Complex, and generating the sinistral Longquanguan ductile shear zone between the Fuping Complex and the Wutai Complex, respectively. The STZ1 and D2 deformation were possibly responsible for fast syn-collisional exhumation of the high pressure mafic granulites and retrograded eclogites. The structural patterns and elucidation of the deformation history of the Hengshan–Wutai–Fuping Complexes places important constraints on the tectonic model suggesting that an oceanic lithosphere between the Eastern and Western Blocks underwent northeastward-directed oblique subduction beneath the western margin of the Eastern Block, and that the final closure of this ocean led to collision between the two blocks to form the coherent basement of the North China Craton. [Copyright &y& Elsevier]

A paleomagnetic study was carried out on Early-Middle Jurassic sediments in the Zhenba area, the western South-dabashan orogenic belt. Stepwise thermal demagnetization isolated the characteristic high temperature component (HTC) (D=37.1°, I=46.1°, α95=10.1°), which passed the fold test. By comparing the corresponding pole of HTC (57.6°N, 196.6°E, A95=9.9°) with coeval reference poles for the Sichuan basin, we detected a 26.5°±9.0° clockwise rotation of the study area relative to the stable Sichuan basin. We interpret that this rotation was caused by obstruction of the Hannan block during thrusting of the Dabashan, and occurred around Early Cretaceous. [ABSTRACT FROM AUTHOR]

Abstract: Simultaneous determinations of U–Pb dating and Hf isotopes on single zircon grains by excimer laser-ablation quadrupole and multiple-collector ICP-MS and petrologic and ore geochemical studies have been applied to the ore-bearing porphyry of the Jinduicheng porphyritic molybdenum deposit in East Qinling. Lithogeochemical data show that the porphyry is characteristic of high K2O, K-feldspar porphyritic calc-alkaline granitoids with 176Hf/177Hf=0.282020–0.282436 and ε Hf(t)=−23.7 to −8.9, which indicates its mixed origin involving a crustal and a mantle component. The weighted average U–Pb age from single zircon grains of the porphyry is 141.5±1.5Ma. This age coincides with the oldest molybdenite Re-Os model age as dated by others, suggesting that the period of mineralization was almost simultaneous with the porphyry emplacement, or slightly later. The porphyry intrusion and the molybdenum mineralization occurred during the transition from compression to extension in the Jurassic – Cretaceous periods. The corresponding tectonic setting was the intracontinental orogenic and extension stage after collision and orogenesis between the Southern China plate and the Northern China plate. The Jinduicheng porphyry and the deposit''s geochemical data indicate that the ore-forming material originated from a mixing of lower crust and upper mantle. When the molybdenum-enriched magma intruded into the upper crust along zones of structural weakness, ore-forming fluid generated by magma crystallization of the porphyry interacted with wall rock or mingled with meteoric water to form the deposit. [Copyright &y& Elsevier]

Abstract: The western Dabie orogen (also known as the Hong''an block) forms the western part of the Dabie–Sulu HP–UHP belt, central China. Rocks of this orogen have been subjected to pervasive ductile deformation, and include numerous quartz schists and felsic mylonites cropping out in ductile shear zones. Quartz textures in these mylonites contain important clues for understanding the movement sense of late-collisional extrusion and exhumation of high-pressure–ultrahigh-pressure (HP–UHP) rocks from the lower crustal level to the upper crustal level during Middle Triassic and Early Jurassic. The orientation and distribution of quartz crystallographic axes were used to confirm the regional shear sense across the orogen. The asymmetry of c-axis patterns consistently indicates top-to-the-southeast thrusting across the orogen in early structural stages. Later stages of deformation show different senses of movement in northern and southern parts of the orogen, with top-to-the-northwest sinistral shearing recorded in rocks north of the Xinxian HP–UHP eclogite-facies belt, and top-to-the-southeast dextral shearing south of the same unit. Based on our study on quartz c-axis fabrics and marco- to micro-scale structures, simultaneous southeastward shearing within a large part of the orogen and normal faulting north of the Xinxian HP–UHP unit is explained by upward extrusion in early stages of deformation. The extrusion process has been attributed to syn- and late-collisional processes, accounting for some earlier deformation in the western Dabie orogen such as metamorphic sequences around the core of the Xinxian HP–UHP eclogite-facies unit. Much higher pressure of deformation is also indicated in the aligned glaucophane and omphacite from blueschist and eclogite in the field. An orogen-parallel eastward extrusion of the Xinxian HP–UHP eclogite-facies unit, however, occurred diachronously in later stages of deformation. Therefore, a tectonic model combining an early upward extrusion with a later eastward extrusion is presented. Two different stages and types of extrusion for exhumation of HP–UHP rocks are suitable to all of east central China. Geochronological data shows that the first, upward extrusion occurred during Middle Triassic, the second, eastward extrusion occurred during Late Triassic to Early Jurassic. These two extrusions are correlative with two stages of rapid exhumation of the Dabie HP–UHP rocks, respectively. These two-stage late-collisional (Middle Triassic to Early Jurassic) extrusion events bridge the gap between syn-collisional (Early to Middle Triassic) vertical extrusion and post-collisional (Cretaceous) eastward-directed lateral escape and provide vital clues to understanding the more detailed processes of exhumation of HP–UHP rocks. [Copyright &y& Elsevier]

Abstract: The geologic framework of the Phanerozoic Qinling–Dabie orogen was built up through two major suturing events of three blocks. From north to south these include the North China craton (including the north Qinling block), the Qinling–Dabie microblock, and the South China craton (including the Bikou block), separated by the Shangdan and Mianlue sutures. The Mianlue suture zone contains evidence for Mesozoic extrusion tectonics in the form of major strike–slip border faults surrounding basement blocks, a Late Paleozoic ophiolite and a ca. 240–200 Ma thrust belt that reformed by 200–150 Ma thrusts during A-type (intracontinental) subduction. The regional map pattern shows that the blocks are surrounded by complexly deformed Devonian to Early Triassic metasandstones and metapelites, forming a regional-scale block-in-matrix mélange fabric. Five distinct tectonic units have been recognized in the belt: (1) basement blocks including two types of Precambrian basement, crystalline and transitional; (2) continental margin slices including Early Paleozoic strata, and Late Paleozoic fluviodeltaic sedimentary rocks, proximal and distal fan clastics, reflecting the development of a north-facing rift margin on the edge of the South China plate; (3) out of sequence oceanic crustal slices including strongly deformed postrift, deep-water sedimentary rocks, sheeted dikes, basalts, and mafic–ultramafic cumulates of a Late Paleozoic ophiolite suite, developing independent of the rift margin in a separate basin; (4) out-of-sequence island-arc slices; (5) accretionary wedge slices. All the tectonic units were deformed during three geometrically distinct deformation episodes (D1, D2 and D3 during 240–200 Ma). Units 2–4 involved southward thrusting and vertical then southward extrusion of about 20 km of horizontal displacement above the autochthonous basement during the D1 episode. Thrust slices 20 km south of the Mianlue suture are related to this vertical extrusion due to the same rock assemblages, ages and kinematics. The D2 and D3 episodes folded all the units in a thick-skinned style about east–west (D2) and west–northwest (D3) axes in the Mianlue suture zone. An early foreland propagating sequence of accretion of Late Paleozoic rocks deposited above the Yangtze craton is not involved in D1 deformation but is temporally equivalent to the D2 and D3 deformation in the Mianlue suture. Two stages of strike–slip faulting mainly occurred at the end of D2 and D3, respectively. During D2 deformation, the Bikou block was obliquely indented to the ESE into the Mianlue suture, rather than being thrust over the Mianlue suture from the north as a part of the Qinling–Dabie microblock. During D3 deformation, however, the Bikou block was bounded by the south boundary fault of the Mianlue suture, and the Yangpingguan fault on the south. These faults are coeval strike–slip faults, but of opposite senses, and accommodated minor southwestward extrusion of the Bikou block into Songpan–Ganze orogen. The other basement blocks north of the Mianlue suture were extruded eastward by about 20 km of lateral displacement, based on the offset of the Wudang dome, during the D3 episode due to the northeastward indentation of the Hannan complex of the South China craton. Post-D3 emplacement of granite, cutting across the strike–slip faults such as the Mianlue suture, provides a minimum age of 200 Ma for D3 deformation. Therefore, based on insights from the evolution of the Mianlue suture, the D2 and D3 episodes in the Mianlue suture and its neighbors are not responsible for and associated with the two-stage extrusion of the Dabie UHP-HP terranes from the Foping dome to the present erosional surface (more than 350 km). [Copyright &y& Elsevier]

As an important part of the global continents, China continent has long been situated in the peculiar tectonic position and experienced extremely complicated activities, which resulted in the regional unique characteristics for China continent on the global common geological background. These characteristics contain abundant information regarding scientific key issues of modern geological frontier. Thus, China continent can be a natural laboratory and excellent arena for the modern geosciences. The modern earth sciences have started entering the era featured with earth systematic science and beyond plate tectonics. How to take the regional advantage and exploit the treasure resource to participate the new theoretical and methodological creation is a historic opportunity and great challenge we are facing. This paper generalizes research priorities in four fields on China continental geology and tectonics for discussion. They are: China continental tectonics and dynamics; Mesozoic-Cenozoic crustal deformation and deep-seated processes in China continent and the adjacent regions; deep seated dynamic background and evolutionary trend of crustal tectonic activities on the time scale of human existence: deep-seated background and processes of conjunction and transformation of different tectonic systems. [ABSTRACT FROM AUTHOR]

Determines the age of the Anzishan granulites in the Mianxian-Lueyang suture zone of Qingling orogen in the Anzishan area, Mianxian County in Shaanxi Province, China. Sm-Nd isochron and [sup40]Ar/[sup39] ages of mineral samples from the granulites; Relation of the formation and uplift of the granulites to the subduction of the Yangtze block beneath the South Qinling microcontinent.

Examines the ultrabasic rocks in the Mianxian-Lueyang ophiolitic melange zone, China. Discussion on the geology and petrography of the ophiolite and island-arc volcanic rocks; Geochemical characters of the ultrabasic rocks; Formation age and geotectonic significance of the ophiolite and island-arc volcanic rocks.

• The ore-forming fluid is characterized by medium-temperature, low-salinity and CO 2 -rich. • Fluid immiscibility and fluid–rock interaction resulted in the gold precipitation. • The δ34S variation reveals different sulfur sources. • The Maanqiao deposit is an orogenic type related to the Indosinian Qinling orogeny. The western Qinling orogen (WQO) is one of the most important prospective gold provinces in China. The Maanqiao gold deposit, located on the southern margin of the Shangdan suture, is a representative gold deposit in the WQO. The Maanqiao deposit is hosted by the metasedimentary rocks of the Upper Devonian Tongyusi Formation. The EW-trending brittle-ductile shear zone controls the orebodies; they occur as disseminated, and auriferous quartz–sulfide vein. The ore-related hydrothermal alteration comprises silicification, sulfidation, sericitization, chloritization, and carbonatization. Native gold is visible and mainly associated with pyrite and pyrrhotite. Mineralization can be classified into the following three stages: bedding-parallel barren quartz–pyrite–(pyrrhotite) (early-stage), auriferous quartz–polymetallic (middle-stage), and carbonate–(quartz)–sulfide (late-stage). Detailed fluid inclusion (FI) studies revealed three types of inclusions in quartz and calcite: aqueous (W-type), CO 2 –H 2 O (C-type), and pure carbonic (PC-type) FIs. The primary FIs in the early-stage quartz are C- and PC-type, in the middle-stage quartz are mainly W- and C-type, and in the late-stage calcite are only W-type. During gold mineralization, the total FI homogeneous temperatures evolved from 189–375 °C (mostly 260–300 °C) to 132–295 °C (mostly 180–240 °C) to 123–231 °C (mostly 130–150 °C), and the salinities varied among 2.2–9.1 wt.% NaCl equiv. (mostly 5–8 wt.%) to 0.2–9.0 wt.% NaCl equiv. (mostly 3–6 wt.%) to 0.3–3.6 wt.% NaCl equiv. (mostly 2–4 wt.%). The ore-forming fluid was characterized as an H 2 O–NaCl−CO 2 −CH 4 –(N 2) system with medium-low temperature and low salinity. The fluid immiscibility and fluid-rock interaction may be responsible for the precipitation of the sulfides and gold at the Maanqiao gold deposit. Three types of pyrite corresponding to the three mineralization stages, as well as pyrrhotite and arsenopyrite in the middle stage, are micro-analyzed for in-situ sulfur isotopic composition by LA-ICP-MS. Py1 yield near-zero δ34S values of −2.5‰ to 3.0‰, which are somewhat lower than that of the granite hosted pyrites (Py-g, 4.8‰ to 6.6‰). The result suggests a mixed sulfur source from magmatic-hydrothermal fluids and the metamorphism of diagenetic pyrite. Pyrite + pyrrhotite + arsenopyrite assemblages in the middle-stage have relatively higher δ34S values (6.6‰ to 12.3‰) and are mainly developed due to the metamorphism of the ore-host and underlying Devonian sedimentary sequences. The low δ34S values of the late-stage fracture-filled Py3 (−21.9‰ to −17.0‰) resulted from an increasing oxygen fugacity, which was caused by the inflow of oxidized meteoric waters. Based on our studies, the Maanqiao gold deposit is considered to be an orogenic type and closely related to the Indosinian Qinling orogeny. [ABSTRACT FROM AUTHOR]

Summary: Ancient wood pagodas, as the excellent representative of ancient China, play an important role in Chinese historical, art, and scientific aspects. Because most pagodas are lacking maintenance for a long time and the long term reinforcement measure has not been determined, it is necessary to carry out an emergency reinforcement method to avoid further damage. This paper presents a design guideline of emergency reinforcement method for ancient wood pagodas. Field tests based on pulsating method were carried out to identify the dynamic characteristics, structural stiffness, and structural damages. The modal frequency, modal shape of different columns and stiffness of each story indicate that the second apparent story is the weak point of the whole structure. To effectively analyze the nonlinear performance of the second apparent story and verify the superiority of the emergency reinforcement method, three elaborated finite element models of the second apparent story in undamaged, and current and reinforced states are established. The buckling analysis shows that the emergency reinforcement method could improve the critical load 89% nearby compared with the current structure. In addition, the seismic analysis proves that the emergency reinforcement method has positive effects on strengthening the weak point to against the earthquakes. [ABSTRACT FROM AUTHOR]

The number of COVID-19 infections has increased sharply and quickly after optimizing the COVID-19 response in China. In the context of this population-size infection, college students' psychological response is yet to be understood. A cross-sectional study was designed to investigate anxiety, depression, insomnia, and post-traumatic stress disorder (PTSD) symptoms among college students from December 31, 2022, to January 7, 2023. The questionnaire included the Generalized Anxiety Disorder 7 (GAD-7), Patient Health Questionnaire 9 (PHQ-9), Insomnia Severity Index (ISI), Impact of Event Scale (IES-R), and self-designed questionnaire. Of the 22,624 respondents, the self-reported prevalence of anxiety, depression, insomnia, PTSD, and any of the four psychological symptoms appeared as 12.7 %, 25.8 %, 11.6 %, 7.9 %, and 29.7 %, respectively. The self-reported COVID-19 infection rate was 80.2 %. Changes in the place for learning, longer time online, not recovering after infection, a higher proportion of family member infection, insufficient drug reserve, worry about sequela after infection, future studies, or employment contributed to a higher risk of anxiety/depression/insomnia symptoms or PTSD symptoms. Multinomial logistic regression showed that those who spent more extended time on the Internet, recovered after infection, and had insufficient drug reserves were less likely to have PTSD than anxiety/depression/insomnia symptoms. The study was a non-probability sampling survey. Anxiety, depression, insomnia, and PTSD were common psychological symptoms among college students when infection went through a large-scale population. This study highlights the importance of continuing to care for the psychological symptoms of college students, especially timely responses to their concerns related to the epidemic situation and COVID-19 infection. • The self-reported COVID-19 infection rate among investigated college students was 80.2%. • The self-reported prevalence of anxiety, depression, insomnia and PTSD appeared as 12.7%, 25.8%, 11.6% and 7.9%. • Attention should be paid to the long-term psychological impact of COVID-19 epidemic and infection on college students. [ABSTRACT FROM AUTHOR]

The Wenquan Mo deposit in Gansu Province, China, is one of the large porphyry Mo deposits in the Western Qinling Orogen that associated with the Triassic continental collision between the North China Block and South China Block. In this study, detailed fluid inclusions (FIs) analyses were performed on early stage quartz–biotite–K-feldspar veins, middle stage quartz–polymetallic sulfide veins and late stage sulfide–calcite veins. Four compositional types of FIs are observed, including pure CO 2 (PC-type), CO 2 -H 2 O (C-type), H 2 O-NaCl (W-type), and daughter mineral-bearing polyphase (S-type, with no halite daughter mineral). The early stage quartz contains all the four types, which are mainly homogenized between 285 °C and 495 °C, with salinities ranging from 4.2 to 17.6 wt% NaCl eqv. However, in the middle stage, PC-type FIs are not observed, and S-, W- and C-types FIs yield homogeneous temperatures (T h ) of 200–397 °C and salinities of 2.4–13.1 wt% NaCl eqv. Late stage quartz contains only W-type FIs with T h of 102–246 °C and salinities of 1.2–10.1 wt% NaCl eqv. Results indicate that the fluid-system evolved from an initial CO 2 -rich magmatic-hydrothermal fluid to a late CO 2 -poor meteoric fluid. In the early and middle stages, it is possible that heterogeneous FIs associations may have been trapped from a fluid immiscibility system. The dramatically decreasing percentage of PC- and C-types FIs in the ore stage indicates that CO 2 escaped, which is possibly the result of earlier fluid immiscibility and phase separation. In addition, there are double peaks of T h in this stage that are obviously lower than in the early stage, showing that meteoric water flowed into and mixed with magmatic fluids, thereby cooling the hydrothermal system. These results suggest that metal precipitation resulted from fluid immiscibility, CO 2 escape, and inflow of meteoric water occurred in the middle stage. The initial fluids of the Wenquan deposit are characterized by relatively high temperature, high salinity, high f O 2 , and are CO 2 -rich and NaCl-poor, indicating that the Wenquan deposit is a collisional-type porphyry Mo deposit. The oxygen fugacity ( f O 2 ) constrained by trace element compositions of zircons from the Wenquan Mo-bearing porphyry is uneven with ΔFMQ −10.3–+4.68 (average of −4.32), which could result from the input of mafic magma and its inhomogeneous mixing with felsic magma. Such values are still much higher than those of the adjacent contemporaneous Mo-barren Lujing, Baijiazhuang, Jiaochangba, Luchuba, and Zhongchuan granitic plutons, which confirms the affinity between Mo mineralization and the oxidized melt system and implies that the Wenquan porphyry has relatively high f O 2 characteristics for its tectonic location and epoch. Fluid inclusion, initial mineralization depth (∼8.6 km), magma f O 2 , and the zircon high U/Yb ratio of the Wenquan Mo deposit strongly suggest that Mo mineralization was related to continental collision, rather than oceanic crust subduction. This study therefore proposes that the Wenquan Mo deposit was formed in a rapid crust uplifting setting caused by syn -orogenic crustal thickening followed by post-orogenic delamination of the lithospheric root during the Late Triassic. [ABSTRACT FROM AUTHOR]

[Display omitted] • Clockwise P–T evolution is recorded by the South Altyn Tagh felsic gneiss. • The felsic gneiss was exhumed from eclogite-facies to granulite-facies within 20 Myr. • HP–HT eclogite-facies records were preserved in the weakly deformed felsic gneiss. • The HP mineralogical records were further eliminated by the strong deformation. Felsic gneisses are usually the dominant rock types in most high-pressure (HP) and ultrahigh-pressure (UHP) terranes, although their peak metamorphic conditions and complete P–T paths are rarely known. This lack of knowledge is attributed to the high variance of mineral assemblages at HP/UHP conditions of the felsic gneisses, or to the effects of retrograde-related overprinting. Thus, it is difficult to distinguish whether felsic gneisses underwent HP/UHP metamorphism. In this paper, we focus on the felsic gneiss that has been previously documented as having formed under HP granulite-facies metamorphism with peak P–T of > 1.15 GPa and > 860 °C from the Danshuiquan locality in the South Altyn HP – UHP belt. The Danshuiquan felsic gneiss is strongly deformed and is spatially associated with weakly deformed garnet-rich felsic gneiss. On the basis of detailed microstructure observations on mineral assemblages and phase equilibria modelling, three stages of metamorphic evolution for the weakly deformed garnet-rich felsic gneiss are identified. The first stage is represented by garnet cores, revealing a prograde P–T path from 1.5 GPa/750 °C to 2.1 GPa/900 °C. The second stage is characterized by garnet mantles with multiphase inclusions, defining HP eclogite-facies metamorphic conditions of 2.2–2.6 GPa/950–1100 °C. The third stage is represented by the composition of garnet rims, biotite, and plagioclase, suggesting an HP granulite to amphibolite facies decompression cooling process to 1.1–1.3 GPa/710–770 °C. In contrast, the strongly deformed felsic gneiss just records a deformation-related decompression process from 1.1 to 1.2 GPa/750–760 °C to 0.87–0.98 GPa/760–770 °C, and finally to 0.83 GPa/740 °C. Zircon U–Pb dating yields c. 920 Ma protolith ages, c. 500 Ma eclogite-facies ages, and c. 480 Ma granulite to amphibolite facies retrograde ages for the Danshuiquan felsic gneisses. Our results show that the Danshuiquan felsic gneisses underwent a similar metamorphic evolution process to that of Yinggelisayi HP–UHP rocks in the eastern segment of the South Altyn Tagh. Most HP mineralogical records tend to be eliminated by the strong deformation at crustal depths (∼30 km), meaning that the peak metamorphic conditions of the studied felsic rocks in UHP metamorphic terranes are previously underestimated. [ABSTRACT FROM AUTHOR]

Abstract: We integrated a systematic sedimentary data into a regional Early Mesozoic stratigraphic framework which demonstrated a detailed picture of spatiotemporal variations in basin deposition and formation in the North China Craton. The Early Mesozoic basin sedimentary evolution is utilized to interpret polyphase tectonism and to unravel the craton deformation. The Late Triassic, nearly WNW-trending, giant intracratonic Ordos basin was widely distributed across most of North China Craton, with a southern wedge-top depozone along the northern East Qilian–Qinling orogenic belt and a northwestern rift depozone along the Helanshan. The continuous subsidence and deposition within the basin were dominantly related to the thrust load of the East Qilian–Qinling belt and inferred mantle flow effects associated with paleotethys plate subduction, and the rift in the northwestern Ordos was driven by nearly north-vergent compression of the eastern North Qilian–North Qinling active margins with the stable North China Craton. This intracratonic Ordos basin formation initiated the deformation of the North China Craton. Formation of the Jurassic NNE-trending walled intracratonic Ordos basin and the broken flexural basins indicates the North China Craton underwent the second, even more abroad nearly NNE trending crustal deformation, with lithosphere thickening in the eastern part of the North China Craton, and dynamic subsidence in the west, which may have been driven by nearly northwestward subduction of the Izanagi plate and the eastward extrusion and underthrusting of the western North China Craton crustal basement. [Copyright &y& Elsevier]

Abstract: The western Qinling is characterized by Triassic granitic plutons, which are keys to constrain the timing of subduction and collisional processes between the North China and South China Blocks. This paper presents a set of new LA-ICPMS U–Pb zircon geochronology, major and trace element geochemistry for several representative diorite and granitoid plutons in the Foping area. The diorites are characterized by high MgO, Al2O3, Y and Yb contents, but low SiO2, Sr/Y and La/Yb ratios, as well as depletion of Nb, Ta, P and Ti, suggesting derived from a subduction related setting. LA-ICPMS zircon U–Pb age of 216.9±1.5Ma (MSWD=0.69) from the diorite constrains the time of the subduction event. The medium- and fine-grained monzogranites as well as the biotite granites exhibit relative high SiO2, MgO and Rb, low Y and Yb contents, and low Sr/Y and La/Yb ratios, as well as various depletions of Nb, Ta, P and Ti. These features indicate a derivation from lower continental crust but had been influenced by slab released fluids in a syn-collisional setting. The medium-grained monzogranite and biotite granite yield LA-ICPMS zircon U–Pb ages of 207.3±2.1Ma (MSWD=1.8) and 201.6±1.2Ma (MSWD=1.04), respectively, proposing the syn-collision during ca. 207–201Ma. Geochemical and geological evidences suggest that the granodiorites intruding in the syn-collisional monzogranites were related to the post-orogenic collapse after the collision between the North China and South China Blocks. The LA-ICPMS U–Pb zircon age of 189.3±2.9Ma (MSWD=5.6) for the granodiorite constrains the time of the post-orogenic collapse. Our geochronological and geochemical data provide important constraints on the Triassic evolution from subduction to collision then up to post-collisional collapse along the Qinling orogen. [Copyright &y& Elsevier]

Traditional metallogenic models posit that porphyry–skarn Cu systems form in subduction and collision zones. However, in eastern China, many important Late Mesozoic porphyry–skarn deposits have formed in intracontinental settings related to lithospheric break-up during the celebrated tectonothermal, Yanshanian event. The Xiaohekou Cu skarn deposit in the southern Qinling Orogen presents an ideal case study to describe such ore deposit geology, using mineral and fluid inclusion analysis, in addition to sulfide and granitoid S Pb isotope studies. A detailed metallogenic process model for the intracontinental skarn Cu deposit is proposed. The authors recognize four main paragenetic stages: (I) anhydrous skarn, (II) hydrous skarn–Fe oxide, (III) quartz–polymetallic sulfide, and (IV) carbonate–quartz. Stage I is characterized by high temperatures (346–547 °C), high to moderate salinities (6.74–49.2 wt% NaCl eqv), together with acidic and oxidizing H 2 O-NaCl fluids. From early to late anhydrous skarn stage, un-zoned grossular (Adr 24–31 Gr 68–74), a grossular–andradite alternation series with wide zones (Adr 26–68 Gr 31–72) and diopside (Di 73–91 Hd 8–24)–pure andradite with dense oscillation zones (Adr 68–100 Gr 0–30) crystallized sequentially, representing a gradual shift toward higher f O 2 conditions. Diopside-hosted fluid inclusions (FIs) contain halite-bearing three phase (H-type), liquid-rich two-phase (L-type), and vapor-rich two-phase (V-type) inclusions, suggesting such fluids were sourced from a silicate melt and stage I & II boiling of magmatic-hydrothermal fluids at lithostatic depths of 1.1–3.3 km.. The FIs in actinolite (stage II) are characterized by homogenization temperatures (T h) of 273–502 °C and salinities of 4.34–42.8 wt% NaCl eqv. Cooling and dilution of the ore-forming hydrothermal fluid, as well as the high f O 2 conditions were responsible for the hydrous skarn alteration in addition to magnetite and specularite deposition. Stage III constitutes the principal Cu mineralizing event. Quartz from this stage contains distinctive liquid-rich inclusions, with T h of 143–423 °C and salinity of 2.07–17.8 wt% NaCl eqv. Their T h values include two populations (210–270 °C and 303–359 °C) suggesting a commingling of hot magmatic-hydrothermal fluid and meteoric water accompanied by a significant f O 2 decrease and pH increase was a principal factor behind chalcopyrite-pyrite-pyrrhotite deposition. The fluids in stage IV (81–218 °C and 0.18–14.1 wt% NaCl eqv) are likely be the chilled equivalent of fluid from the Cu mineralization stage which equilibrated with marble. S Pb isotopes reveal that the metals were derived from the granitic rocks and produced by hybrid (mantle+crust)-derived magmas. We propose hydrothermal fluids exsolved from the cooling granitic magma contributed the majority ore-forming materials. Whereas ore-forming fluids clearly interacted with country rocks affecting ore precipitation, skarn development and deposit geometry and emplacement. Devonian host rocks donated little if any of either sulfur or base metals to the mineralization process. [Display omitted] • Proposing a metallogenic process model for the intracontinental skarn Cu deposit. • Hydrothermal fluids exsolved from the hybrid magma contributed ore-forming materials. • Host strata rocks contributed little sulfur and metals but affected ore precipitation. • Fluid mixing happened between magmatic-hydrothermal fluid and meteoric water. • f O 2 decrease and pH increase may be the mechanisms for the Cu-mineralization. [ABSTRACT FROM AUTHOR]

The Neoproterozoic assembly and break-up of Rodinia have not only caused reconfiguration of the global tectonic architecture of oceans and continents, but also led to active tectonic processes and basin fillings which consequently effected the Earth's habitability. The Yangtze Block preserves abundant Neoproterozoic magmatic rocks along its edges and sedimentary successions in the inner shield for reconstruction of the tectonic evolution of Rodinia. The Rodinia landmasses were surrounded by the exterior Pan-ocean and separated by the interior oceans during the latest Mesoproterozoic (ca. 1.17–1.02 Ga). The Yangtze Block was situated at the northwestern edge of Rodinia, facing the exterior ocean to the north and west, and evolved into a Neoproterozoic co-evolution of coupling inner basins and three marginal orogens. The Jiangnan Orogen in the east was formed by long-term subduction-collision between the Yangtze and Cathaysia blocks from ca. 1000–820 Ma, and represents an interior orogen corresponding to the assembly of Rodinia. In comparison, the Longmen-Kangdian Orogen was an Andean-type subduction orogen along the western active continental margin from ca. 870–720 Ma, while the South Qinling Orogen was a wide accretionary orogen to the north of the nucleus of the Yangtze Block from ca. 880–720 Ma. Both the Longmen-Kangdian Orogen in the west and the South Qinling Orogen in the north were exterior orogens of Rodinia. The exterior subductions from ca. 880 to 820 Ma were synchronous with the assembly of Rodinia; however, the continuous exterior subductions along the western and northern Yangtze Block (the outer part of Rodinia) during ca. 820–720 Ma might have coincided with the break-up of Rodinia. The different spatiotemporal properties of sedimentary fillings and the evolution of the inner Yangtze basin were controlled by the Neoproterozoic tectonic evolution of the three orogens. From ca. 1000–880 Ma, the exterior ocean was undergoing extension, resulting in passive continental marginal deposition, while the interior Paleo-South China oceanic slab subducted beneath the E-Yangtze Block, leading to an arc-related continental marginal basin. Up to ca. 880–820 Ma, the westward interior subduction-collision generated the closure of the Paleo-South China interior ocean, leading to the collision of the Yangtze and Cathaysia blocks at ca. 820 Ma. The southward and eastward exterior subductions from ca. 820 to 720 Ma led to a wide accretionary continental marginal orogen in the South Qinling Belt and an Andean-type active continental arc along the Longmen-Kangdian Belt. The continuous exterior subduction along the W- and N-Yangtze Block, together with the collapse of Jiangnan Orogen, led to the interior rifting in the inner Yangtze Basin filled with a thick-pile of rift-related successions. From ca. 720–635 Ma, the W-Yangtze Block transmitted to a westward-deepening passive continental margin, while the E-Yangtze Block was still in rift basins. Most areas of the Yangtze Block have evolved into an extensional basin, which accumulated with widespread glacial-interglacial deposits. Afterwards, the whole Yangtze Block evolved into a depressional basin filled with the Ediacaran and Cambrian shallow-marine or bathyal-abyssal facies clastic and carbonate successions. [Display omitted] • Yangtze Block evolved by coupled Neoproterozoic evolution of inner basins and marginal orogens. • Jiangnan Orogen records interior subduction-collision of Yangtze and Cathaysia in ca. 1.0–0.82 Ga. • South Qinling Orogen was formed by a long-term exterior subduction-accretion during ca. 880–720 Ma. • Longmen-Chuandian Orogen was an exterior Andean-type continental margin arc in ca. 870–740 Ma. • Inner Yangtze Block evolved from arc-related to depressional/rift basins in the Neoproterozoic. [ABSTRACT FROM AUTHOR]

• One of the few skarn-type, commercial deposits in the Zha-Shan ore district. • Granitoids were mainly sourced from thickened lower crust with adakitic affinity. • Oxidized mantle component was the most likely factor to improve magma f O 2. • The deposit was formed in the Qinling intracontinental orogeny during 141–138 Ma. The Xiaohekou copper deposit is one of the few typical skarn-type, commercial deposits in the Zha-Shan ore cluster area in the eastern part of South Qinling. The ore-related granitoids in the Xiaohekou mining district include a number of small plutons of granodiorite porphyry and granite porphyry, as well as numerous dykes. They are characterized by relatively low SiO 2 (65.9–73.3 wt%) and MgO (0.26–1.72 wt%) contents, variable Mg# (29.4–64.0) values, high K 2 O (3.11–5.75 wt%) content and negligible δEu (1.00–1.15) values. The samples also exhibit depletion in Cr, Ni, Nb, Ta, and Ti content, and high Sr/Y (46.6–64.7) and La/Yb (17.0–25.0) ratios. These features are similar to those of high-K calc-alkaline adakite-like magma formed by partial melting of thickened lower crust in continental collision zones or intracontinental settings. The majority of the samples have T DM2 (Hf) of 1.5–1.2 Ga, corresponding to weakly negative ε Hf (t) values (−4.75 to −0.13) typical of crustal material, but more than one quarter have T DM1 (Hf) of 0.80–0.71 Ga, corresponding to positive ε Hf (t) values of +0.07 to +2.45, indicating that the granitoids resulted from partial melting of Mesoproterozoic lower crustal rocks with significant input from enriched lithospheric mantle-derived magmas. Zircons from the Xiaohekou granitoids have ΔFMQ values concentrated around −0.62 to +5.54, most of which show the magma f O 2 of FMQ to HM, in accordance with the widespread occurrence of magnetite, hematite and specularite in the Xiaohekou skarn system, which is an indicator of relatively high f O 2 for a magmatic–hydrothermal system. The granitoids exhibit similar or even higher Ce4+/Ce3+ (average of 452) and Eu/Eu* (average of 0.72) values in comparison with those of fertile Cu deposits worldwide, indicating that the Xiaohekou granitoids may possess the potential to form a large magmatic–hydrothermal Cu deposit. Zircons of the granitoids show obvious positive correlations between oxidation indices (Ce and Eu anomalies, Ce4+/Ce3+ ratios, and ΔFMQ values) and ε Hf (t) values, implying the involvement of an oxidized mantle component which might have caused the f O 2 elevation and played an important role in the formation of Cu deposits. The zircon U–Pb ages (141.3 ± 1.3 and 138.1 ± 2.0 Ma) of the Xiaohekou ore-related granitoids obtained in this study are similar to the zircon U–Pb and molybdenite Re–Os ages yielded from porphyry Mo mineralization at the Chigou and Lengshuigou deposits in the Zha-Shan ore district, indicating that they are possibly part of a single tectonic, magmatic, and metallogenic event in the Yanshan orogeny. The ore-related granitoids in the Xiaohekou area were formed in a post-collisional compression–extension transition regime during the Early Cretaceous Qinling intracontinental orogeny. The orogeny can be attributed to the far-field effect of a switch from pre-Mesozoic Tethyan tectonics to Late Mesozoic Pacific tectonics. This triggered a stress field transition from N–S to E–W trending and from intracontinental subduction thickening to large-scale lithospheric delamination and thinning. [ABSTRACT FROM AUTHOR]

The Mesozoic Western Pacific subduction system significantly impacted the North China and South China blocks along the East Asian continental margin and influenced the tectonic, magmatic, metallogenic and geomorphic evolution of the region. However, the dynamics and impact on the zone along the East Asian ocean-continent connection zone remain debated. Here we provide a comprehensive synthesis of the state-of-the-art information from deformation analysis, magmatism, geochronology, tomography and other fields from this region. We evaluate first the pre-Yanshanian (pre-Jurassic) final assembly of blocks and the Late Triassic formation of the unified continental margin in East China. We then focus on the Jurassic and Cretaceous geological processes in the East Asian ocean-continent connection zone. The temporal and spatial evolution of structural propagation, sedimentary depocentre, age zonation and migration of magmatism, as well as the large-scale tectono-morphological inversion in the Earth surface system combined with deep processes, are probed. In the early Yanshannian Period (Early and Middle Jurassic, 200–160 Ma), the destruction of the North China Craton (NCC) was mainly affected by the westward early-stage layered rollback, and stepwise delamination and thinning of its continental lithosphere, resulting in the early Yanshanian westward migration of tectonism and magmatism. Coevally, the combined effect of the closure of the Mongal-Okhotsk Ocean to the north and the subduction of the Bangong-Co- Nujiang Ocean to the south imparted an overall compressional setting in the East Asian Ocean-Continent Connection Zone (EAOCCZ). The centres of asthenospheric upwelling and mantle extrusion at depth continued to migrate eastward, driving the eastward lithospheric thinning with periodic and alternating extension and compression. The South China Block experienced a westward flat subduction during the early Yanshanian Period, resulting in the westward propagation of deformation and magmatism, followed by late two-stage delamination to induce the eastward tectono-magmatism. The difference in tectono-magmatic styles between the North China and South China blocks is a result of the different mechanisms and syles of the deep delamination processes under the superconvergence regime of the East Asian and adjacent plates. Especially delamination under North China generated the northwestward layered and fractured subcontinental lithospheric mantle, whereas under the eastern South China Block, were the oceanic lithospheric mantle of the Paleo- Pacific Plate that underwent flat subduction, or continental garnet peridotite mantle. In the middle Yanshanian Period (Late Jurassic to early Early Cretaceous, 160–125 Ma), the EAOCCZ underwent escape tectonics to form some basins related to strike slip faulting. Generally the extensional basins in the tails of the triangular-shaped escape blocks are perpendicular to the extrusion direction. The transtensional or transpressional basins are controlled by the strike slip faults distributed on both sides of the triangular block, and the flexural basins occur in front. In the late Yanshanian Period (late Early Cretaceous-Late Cretaceous, 125–65 Ma), the Paleo-Pacific (Izanagi) Plate subducted NNW-ward beneath the Eurasian continent, and the subduction angles changed gradually following eastward mantle extrusion induced by the closure of the Okhotsk Ocean to the north and Bangong-Nujiang Ocean to the south, as well as the rollback and subduction retreat of the Paleo-Pacific Plate to the east. The EAOCCZ gradually experienced lithospheric collapse and the formation of metamorphic core complexes, as well as obvious landscape reversal. During 70–45 Ma, the Izanagi-Pacific Ridge subducted beneath the EAOCCZ to induce wide uplift resulting in the formation of the Cenozoic dextral transtension-related basins. [ABSTRACT FROM AUTHOR]

Objective: Psychosocial factors have been associated with a decline of the quality of semen. The study was aimed at (i) estimating the association between work stress and semen quality and (ii) exploring the moderating effect of social support in semen parameters among Chinese male workers.Methods: Data were obtained from 384 adult male workers recruited from April 2014 to December 2015 in Chongqing, China. Participants completed a questionnaire assessing demographic and life-style factors. Work stress and social support was measured by the Chinese version of a 22-item Job Content Questionnaire (JCQ). They underwent a physical examination and provided a semen sample.Results: Subjects with high work stress were associated with a higher risk of being classified below WHO's thresholds for "normal," defined by sperm concentration (OR 2.14, 95% CI 1.24-3.68, p = .006) or total sperm count (OR 1.95, 95% CI 1.13-3.36, p = .02) criteria than subjects with low work stress were. However, these adverse associations were not observed among subjects with high social support (p = .80 for sperm concentration, and p = .39 for total sperm count). Interaction effects between social support and work stress on sperm concentration (p = .002) and total sperm count (p = .02) were detected.Conclusion: Work stress is associated with lower levels of semen quality. Social support attenuates the negative association between work stress and semen quality, which may have implications for reproductive health. [ABSTRACT FROM AUTHOR]

Highlights • The kinds of negative life events Chinese male senior college students encounter were described. • Both univariate and multivariate logistic regression analyses were used. • Negative life events were positively related to depression, anxiety, and stress symptoms. • Statistically, serum cortisol level was unrelated to depression, anxiety, and stress scores. Abstract The aims of this study were to explore the associations between negative life events and anxiety, depressive, and stress symptoms among male senior college students who experience negative life events in daily life. Data were obtained from 582 male senior college students recruited from universities in Chongqing China. Participants completed the Adolescent Self-rating Life Events Checklist (ASLEC), and the Depression, Anxiety, and Stress Scale-21 (DASS-21). Socio-demographic information, lifestyle information, and a blood sample were acquired. 39 (6.7%), 74 (12.7%), and 39 (6.7%) subjects were depressed, anxious, and stressed, respectively. The results confirmed that negative life events were positively related to mental health problems. Different types of negative life events had their specific associations with being depressed, anxious, or stressed. With respect to different types of negative life events, subjects with more "interpersonal relationship" related problems had a higher probability of being anxious and stressed; whereas, subjects with more "change for adaptation" related problems had a higher probability of being depressed and anxious. These results indicate that more concerns over the events with both high occurrence rate and severity might be helpful to mental health prevention and promotion for senior college students. [ABSTRACT FROM AUTHOR]

Traditional energy-economy nexus analysis is limited to aggregated and annual data because more detailed energy consumption data are usually not available. However, probing the disaggregated sectoral data usually provides a deep insight of energy-economy nexus at sectoral level, which is vital for governments to make proper policies in a timely manner. This paper developed a deep research to find detailed quarterly and sectoral nexus between electricity consumption and economic growth. Sectoral data of electricity consumption and economic growth from 2005Q1 to 2016Q3 in Beijing were exploited to model with Granger causality analysis. The results show that at the aggregated level there is a unidirectional causality running from economic growth to electricity consumption. At sectoral level, for the primary sector the electricity consumption impacts its added value with two quarter lagged; for the secondary sector and the tertiary sector, there is a unidirectional causality running from economic growth to electricity consumption. At cross-sector level, the economic growth of the secondary sector has no impact on that of the tertiary sector, while the economic growth of the tertiary sector strongly affects that of the secondary sector. In terms of energy saving and emission reduction, different policies should be employed in the three sectors. Beijing should encourage the electrification of the primary sector to stimulate its development; Beijing should make more efforts on tertiary sector to reduce electricity consumption however these policies should be more prudent. While for the secondary sector, improving energy efficiency and technological innovation should be paid more attention to. [ABSTRACT FROM AUTHOR]

The Neoproterozoic magmatism in the South Qinling Belt and northern margin of the South China Block is important key to understanding the tectonic evolutionary history of the South China Block, and to reconstruct the tectonics of the supercontinent Rodinia. The Xiaomoling magmatic complex in the South Qinling Belt consists mainly of basalts in the Mogouxia area, gabbros and diorites in the Chishuigou, Lengshuigou and Qianyouhe areas. The basalts in the Mogouxia are characterized by depletion of LREEs and LILEs, and non- differentiation of HFSEs, suggesting their deviation from a slightly depleted MORB mantle source. Taken together with geochemical and geological data, the basalt in the Mogouxia area is interpreted to have derived from a subduction-related back-arc basin setting. The gabbros from both Chishuigou and Lengshuigou sections display clear LREE, Th, and LILEs enrichment, and depletion of Nb, Ta and Ti, and highly differentiation in HFSEs, which are similar to that of a typical Island Arc Basalts. The diorites from both Chishuigou and Qianyouhe areas display strong LREE enrichment, depletion of Nb, Ta, P and Ti, enrichment of LILEs, and flat distribution pattern of HFSEs in the primitive mantle-normalized trace element pattern. According to their geochemistry, both gabbros and diorites from different localities of the Xiaomoling magmatic complex were mostly likely formed in an island-arc tectonic setting. The zircons concentrated from the gabbro and diorite yield LA-ICPMS U-Pb ages of 753 ± 4 Ma and 843 ± 5 Ma, respectively, representing their formation ages. Integrated all the available geological, geochemical and geochronological data, we propose that the Xiaomoling magmatic complex represents the northernmost of the accretionary belt to the north of the South China Block, while the Hannan-Huangling Neoproterozoic intrusions mark the southernmost of the accretionary belt. Therefore, the most of southern Qinling represents a wide subduction and accretionary tectonic belt in Neoproterozoic times. Our new geochronology and previously published reliable ages estimate a long-lived subduction during ca. 850–700 Ma at the present South Qinling area, to the north of the South China Block. [ABSTRACT FROM AUTHOR]

Abstract: LA-ICP-MS U–Pb ages of detrital zircons from clastics of the undated fore-arc sedimentary unit (FAS) along the Shangdan Suture and the Middle–Upper Devonian Liuling Group in the South Qinling belt are used to establish the maximum depositional age and provenance of these tectonic units which were deposited on both sides of the Shangdan suture zone between the North China Block (NCB) and South China Block (SCB). The new data and geological evidence show that the FAS was deposited in a fore-arc basin with an exclusive source of the clastics in the North Qinling Belt (NQB). The depositional age of FAS is limited by the youngest U–Pb 455Ma-ages of detrital zircons from clastics and the intrusive age of 435±7Ma of mafic dykes between the Late Ordovician–Early Silurian, while the NCB was still separated from the SCB by the Shangdan Ocean. However, detrital zircon U–Pb ages from six samples of the Middle Devonian Liuling Group indicate sources in both NQB and SCB suggesting pre-Middle Devonian collision of NCB and SCB. All results indicate deposition of the FAS in a forearc setting upon an active continental margin during Late Ordovician–Early Silurian, while the Middle–Upper Devonian Liuling Group represents a marine foreland basin after closure of the Shangdan Ocean. Together with the unconformity between Middle Devonian and pre-Devonian strata, this reveals still evolving subduction and accretion on the southern side of the NQB during the Ordovician-Early Silurian, and the Early Devonian collision between the NCB and SCB. [Copyright &y& Elsevier]

Abstract: The Xuefeng Tectonic Belt is an important intraplate structural system in the South China Block. Its west margin is up to 1300km away the present-day continental margin, and the Mesozoic structural trends in this belt are perpendicular to and have no correlation with the Triassic Qinling-Dabie Orogenic Belt. This belt provides important clues for understanding the mechanism of intraplate deformation and the tectonic history of South China. We identified two generations of folding with different strike directions in the Xuefeng Tectonic Belt based on the youngest folding-involved strata and their overprinting relationship. The early one is NE-striking, overprinted by the N–S-striking folds both during Late Jurassic and Late Cretaceous. Thrust faults in the Xuefeng Tectonic Belt mainly show top-to-west thrust movement, which is approximately coeval with the N–S-striking folding. The thrust fault system can be divided into three zones: the root zone with steep thrusts, the middle zone characterized by imbricate thrusts, and the frontal zone with a few shallow thrusts. In addition, two generations of strike-slip faults with different structural trends have been identified: E–W-striking strike-slip faults showing dextral transpression, and NE-striking strike-slip faults with sinistral offset and controlling the upper Cretaceous basins. According to regional geological relationship and structural overprinting, we interpret that the E–W trending strike-slip faults formed in the first stage, whereas the NE-striking strike-slip faults formed later during an E–W-oriented compressional event. Therefore, the principal stress direction varies from NW–SE to E–W. [Copyright &y& Elsevier]

Abstract: Since Mesozoic, the South China region has been located at the center of a triangular area surrounded by westward subduction of the Pacific plate, northward subduction of the India Plate beneath the Eurasia Plate, and collision of the North and South China blocks along the Central China Orogen. This region thus marks the frontier of a super-convergent regime. Within the super-convergence domain, the compressional structures in the center of the South China Block are mainly characterized by shortening, thrusting and decollement. The block underwent inhomogeneous rejuvenation of the pre-existing crust and lithospheric structures through reactivation of late-stage activities. The surface deformation of the Xuefeng Intracontinental Tectonic System within the South China Block is possibly derived from intraplate tectonics. Particularly, the distinct magmatism between the west and east limbs of the Xuefeng Precambrian Uplift is a possible response of the rheological structure of the lithosphere. The deep structures as revealed from tomographic studies show marked difference of lithosphere architecture between the eastern and western sub-blocks of the South China Block. These data illustrate the long-term mosaic of multi-block convergence which led to present-day inhomogeneity in the continental lithosphere in South China. A comparison of the intensive contraction of the South China Block with the distinct features of rifting of the North China Block, brings out the contrasting structural and tectonic signatures developed in the same frontier of one of the largest super-convergent systems on the globe during the Mesozoic to Cenozoic. [Copyright &y& Elsevier]

Abstract: The Neoproterozoic mafic intrusions and granitoids of the Hannan and Micangshan massifs, located at the northwestern margin of the Yangtze Block in South China, are composed mainly of subduction-related plutons. Here we present LA-ICPMS zircon U–Pb data on the granitoids from Wudumen, Xishenba, Xixiang and Hanshan within the Hannan massif which show crystallization ages of 718±9Ma, 706±9Ma, 707±20Ma and 777±8Ma, respectively. The arc-related Mujiaba gabbros display crystallization age of 746±4Ma. In the Micangshan massif, the crystallization ages of the granodiorite at Daheba, and the granites at Xihe and Guangwushan are 871±77Ma, 832±5Ma and 838±17Ma, respectively, whereas the Shatan diorite, Xihe and Zhengyuan gabbroic intrusions yield crystallization ages of 840±6Ma, 824±4Ma and 857±46Ma, respectively. The tonalites in the Wudumen pluton display adakitic affinity, characterized by strong depletion of Nb, Ta, P and Ti, and enrichment of large-ion lithophile elements (LILE) (i.e. Cs, Rb, Ba, Th, U and K) as well as positive Pb and Sr anomalies, suggesting an origin by the melting of a thickened mafic lower crust at ca. 718Ma. The syenogranite at Xixiang is characterized by depletion of Nb, Ta, Sr, P and Ti, and marked enrichment of LILE, K and Pb, indicating a post-collisional orogenic collapse at ca. 707Ma. The results from our study suggests that the arc-related magmatism migrated from Micangshan area during ca. 870–820Ma, through Huijunba-Xixiang in ca. 840–820Ma, and to Hannan during 825–706Ma, based on which we propose an accretionary tectonic model for the northwestern margin of the Yangtze Block. [Copyright &y& Elsevier]

Abstract: Gneissoid granites were traditionally thought to be the components of the Precambrian basement in the eastern South China Block, but twenty-four gneissoid granite samples from the Wugong, northern Wuyi, southern Wuyi and Yunkai Domains gave zircon U–Pb ages of 424–456Ma, 410–457Ma, 426–438Ma and 415–450Ma, respectively. The existence of the abundant Kwangsian gneissoid granites, which have incorrectly been assigned to the Precambrian basement, indicates that the “so-called” Precambrian stratigraphic sequence of the Cathaysia Block should be termed “Complex” rather than “Group”. These gneissoid granites are peraluminous granites with relatively high Al2O3, MgO, TiO2, FeOt and CaO/Na2O but low CaO, Al2O3/(MgO+FeOt) and Rb/Sr ratios. They exhibit strongly negative Ba, Sr, Nb, P and Ti and positive Pb anomalies in primitive mantle-normalized diagrams, and have initial 87Sr/86Sr ratios ranging from 0.70924 to 0.72935 and negative εNd(t) values from −6.4 to −11.4, similar to those of paragneissic enclaves and Precambrian sedimentary rocks in the eastern South China Block. The zircons crystallized in the Kwangsian gneissoid granites gave εHf(t) values ranging from +2.4 to −19.4 with the peak at −4 (almost all grains clustering at −1 to −12) and Hf model ages of 1.1–2.1Ga. The synthesis of these geochemical and in-situ zircon Hf isotopic data indicates that the Kwangsian gneissoid granites dominantly originated from Proterozoic metapelitic and meta-igneous components with insignificant input of juvenile mantle-derived magmas. A model of two-stage crustal anatexis is proposed for the Kwangsian granitic magma in the eastern South China Block, with (1) the formation of 460–430Ma granite through the breakdown of hydrous minerals under the condition of the doubly thickened crust, and (2) the generation of the 430–400Ma granite accompanying promoted melting along a path of isothermal decompression due to the increasing thermal weakening for the collapse of the thickened crust. The crustal anatexis has probably occurred in an intracontinental tectonic regime that was geodynamically linked to the far-field response to the assembly of the Australian–Indian plate with the Cathaysia Block during middle Paleozoic (Kwangsian) time. [Copyright &y& Elsevier]

Abstract: Along the Qinling–Dabie–Sulu orogenic belt in China crops out the world''s largest terrane composed of ultrahigh-pressure (UHP) metamorphic rocks. Differences in the timing and mechanisms of oceanic and continental subductions are assumed to be responsible for different ages of high-pressure (HP) and UHP slices in different parts of the belt. The western part of the Dabie orogen (western Dabie terrane) holds a key to understanding of the transition from oceanic to continental subduction. This paper reports geochronological results to test a two-stage tectonic model for the exhumation of HP/UHP rocks in western Dabie. This model involves two different stages and types of extrusion for exhumation of the HP/UHP rocks in east-central China. Mica Ar/Ar ages, ranging from 241 to 231Ma, indicate a general middle Triassic cooling probably driven by early upward extrusion during the collision between the North and South China Blocks. Late Triassic–Early Jurassic cooling was associated with later eastward extrusion, ranging from 200 to 184Ma. The second event is recorded also in mica in the region that was not affected by later deformation and magmatism. The lateral movement along lithosphere-scale faults resulted in the eastward extrusion of the HP–UHP metamorphic terrane, which was followed, in the Late Triassic–Early Jurassic time, by a major compressive event. These two extrusion events are correlative with the two stages of Triassic exhumation of the western Dabie HP–UHP rocks, respectively. Wintin the framework of the Qinling–Dabie–Sulu orogenic belt, it is suggested for western Dabie that the subduction/exhumation of blueschist-facies unit is related to the Mianlue suture, whereas the subduction/exhumation of HP/UHP eclogite-facies units is related to the Shangdan suture. [Copyright &y& Elsevier]

Abstract: Abundant exposures of widely-distributed HP–UHP metamorphic rocks in the western part of the Dabie orogen enable us to study the tectonic evolution of HP–UHP terranes associated with the world''s largest preserved continental subduction zone. Previous tectonic models for the Dabie orogen were based largely on metamorphic studies, most of them lacking significant structural constraints. We present a comprehensive structural analysis based on detailed structural geology. The results suggest that syn-UHP (D0 at 241–231Ma) and syn-HP (D1 at 225–215Ma) southeast-vergent thrusting formed a series of stacked structural slices. This was followed by southeast-vergent folding under amphibolite facies conditions (D2 at 215–205Ma); then a third generation of flexural folding occurred at shallow levels (D3 at 200–184Ma). This leads us to proposes a two-stage Triassic exhumation model in which initially rapid vertical extrusion (D0–D1) from UHP to HP conditions to lower crustal levels is followed by slow southeastward extrusion (D3) from lower crustal levels to the Earth''s surface. The tectonic model combines the early southeastward vertical extrusion with the later southeastward lateral extrusion, revealing two different stages and thus different types of Triassic extrusion for the exhumation of HP–UHP rocks in the Dabie orogen. The first stage extrusion occurred in the Middle Triassic, whereas the second stage extrusion lasted from the Late Triassic to Early Jurassic. These two extrusion episodes correlate with the two stages of Triassic exhumation of the Dabie HP–UHP rocks, respectively, during continental collision. [Copyright &y& Elsevier]

The tectonic convergence between the South China block and Qinling belt that occurred in Mesozoic time was not homogeneous along strike; it was mainly concentrated in the Shengnongjia and Hannan domes, which formed a pair of indentors, along which the South China block penetrated the Qinling belt. As a consequence, the Tongbai-Dabie Shan belt, the eastern part of the Qinling orogenic belt, may have undergone large-scale eastward extrusion, clockwise rotation, and uplift, as indicated by its boundary deformation features. It was originally located beneath the narrowest part of the Qinling belt, where it underwent ultrahigh-pressure metamorphism in the Early Triassic. [ABSTRACT FROM AUTHOR]