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Abstract Trace elements in igneous zircon crystals are variable within single crystals or amongst populations of crystals and are particularly sensitive to changes in melt composition. In this study, we present zircon trace element data from both volcanic and plutonic rocks of the Yandangshan caldera complex from SEChina. The erupted rhyolitic rocks are interpreted to represent the most differentiated magma, whereas the intruded porphyritic quartz syenites are thought to be representative of the residual crystal mush. The zircon crystals of both lithologies are subdivided into two types based on their internal structures: type A with a distinct oscillatory growth zoning and type B crystals are bright in cathodoluminescence (CL-bright). Type B zircon occurs as rims of type A zircon or as individual grains. Compared to type A, type B zircons commonly show lower Hf, U, Th and Y concentrations and higher Ti and Zr/Hf and Eu/Eu* ratios. The zircon trace element compositions of the volcanic samples generally overlap those of the intracaldera porphyritic quartz syenite and mafic microgranular enclaves that contain both type A and type B zircons. Despite a general overlap, zircon grains from the volcanic rocks show relatively higher Hf contents and Y/Dy ratios, lower Ti contents and Th/U ratios and larger negative Eu anomalies than the plutonic samples. We suggest that the inter- and intragrain compositional variability of zircon crystals can be used to track the evolution of magmatic systems. We show that in our case, the volcanic and plutonic rocks crystallized continuously during the magmatic evolution in a common magma system and that the magmas of these rocks may be linked by fractional crystallization. Furthermore, the type B zircon grains are inferred to have crystalized in relatively hot and less evolved magma indicating a magma recharge event. Consequently, the geochemical variability of igneous zircon crystals can be used to infer on the magmatic evolution of single volcanic system which may also be applicable in other geodynamic environments. Highlights • Two types of zircon occurred in the Yandangshan volcanic and plutonic rocks. • The volcanic-plutonic connection was revealed by zircon trace elements. • The zircon from different rock units crystallized continuously. • Magma recharge processes were recorded in the zircon domains and some grains. • The compositional variability of zircon can be used to track the magmatic evolution. [ABSTRACT FROM AUTHOR]

Crystal-rich volcanic rocks are important for understanding the evolution of large silicic magma systems. However, the magmatic evolution and rejuvenation processes that form the eruptible crystal-rich magma remain controversial. In this study, we conducted petrological, whole-rock major and trace element geochemical and zircon U–Pb and Hf–O isotopic analyses on the Banshan crystal-rich tuff from the large Cretaceous volcanic belt of southeast China. Systematic SIMS and LA-ICP-MS zircon U–Pb geochronology indicate that the Banshan tuff was formed at ∼114–112 Ma. Their zircon Hf isotopic compositions [ε Hf (t) = −10.9 − 4.2; T DMC = 2.18–1.68 Ga] indicate that the magma of Banshan tuff was derived from a combination of mantle-derived melts and partial melting of the Paleoproterozoic crust of southeast China. In addition, they have low zircon O isotopic compositions (δ18O VSMOW = 4.39–5.36‰) reflecting that the assimilation of wall-rocks which underwent high-temperature hydrothermally exchange with meteoric waters. Extremely Mn-rich garnets in the Banshan tuff (MnO = 30.48–35.82 wt%) suggest that the magma once reached a high degree of crystallization which was nearing consolidation. The subsequent mush rejuvenation caused by magma recharge is evidenced by partly resorbed alkali feldspar, quartz and garnet, as well as the CL-bright rims of zircon. Crystal-rich volcanic rocks are widely distributed in the lower sequences of Cretaceous volcanic strata from southeast China, but rarely developed in the upper sequences. We suggest this reflects that the magmas of lower sequences have higher volatile contents and were formed in a subduction tectonic setting. • The Banshan tuff has Mn-rich garnets crystallized from highly differentiated magma; • Magma of the Banshan tuff reached a high degree of crystallization (> 90%). • Rejuvenation of silicic mush triggered the eruption of crystal-rich magma; • Crystal-rich tuff magmas are volatile-rich and formed in a subduction setting. [ABSTRACT FROM AUTHOR]

As an open economy, China also has a typical dual economy. These two economic characteristics may affect China's inflation in the following three aspects: First, the prices of imported intermediate goods might influence firms' costs. Second, the modes of pricing for food and non-food might be of a great difference as a result of the conduct of most agricultural product prices by government (that is, the market of agricultural products has not been released). Third, the transfer of rural labor force may change the urban labor market balance, and then affect firms' costs. In contrast to previous work, this paper models China's inflation using new Keynesian Phillips curve considering the above three factors and monetary policy shocks. Empirical results show that forward-looking behavior is predominant (accounting for about 2/3 of firms) in non-food sector, and that non-food prices are fixed for about three quarters on average. Real marginal costs including dual economy and open economy elements have a significant impact on inflation dynamics. The transfer of rural labor force also has a significant effect on inflation, but the directly supply-side effect of monetary policy (measured by interest rate) on inflation is insignificant. [ABSTRACT FROM AUTHOR]

• Plagioclases from the porphyritic quartz syenite show relatively high (87Sr/86Sr) i. • Plagioclases from the mafic microgranular enclave show low and variable (87Sr/86Sr) i. • Magma recharge is revealed by inter-grain variation of Sr isotope in plagioclase. • Whole-rock Sr isotope is assemblage of plagioclase with different (87Sr/86Sr) i. In situ Sr-isotope of plagioclase can be used to elucidate the details of magmatic processes. Here we report in situ Sr isotopic compositions of plagioclase from the intra-caldera porphyritic quartz syenite and mafic microgranular enclave of the Yandangshan caldera, SE China. Plagioclase phenocrysts from porphyritic quartz syenite show consistent initial 87Sr/86Sr ratios (0.7088–0.7091). Plagioclases in groundmass of mafic microgranular enclave have low initial 87Sr/86Sr ratios (0.7080–0.7081). In contrast, the plagioclase phenocrysts of mafic microgranular enclave show relatively variable initial 87Sr/86Sr ratios of 0.7081–0.7088, which exhibit distinct inter-grain variation with high values similar to the plagioclase phenocrysts in porphyritic quartz syenite, and low values similar to the plagioclase in groundmass. However, the initial 87Sr/86Sr ratios of individual plagioclases from phenocrysts and groundmass show insignificant intra-grain variation. Furthermore, initial 87Sr/86Sr ratios (0.7080–0.7088) of plagioclase from phenocrysts and groundmass of mafic microgranular enclave are within and lower than the whole-rock initial 87Sr/86Sr ratios (0.7082–0.7088), while the values of plagioclase phenocrysts from the porphyritic quartz syenite are within and higher than the whole-rock initial 87Sr/86Sr ratios (0.7086–0.7089). Therefore, we propose that the inter-grain Sr isotope variation of plagioclase is related to magma recharge events, which induce chemical and physical exchanges between the recharge magma and the host magma and the remobilization of crystal mush in magma reservoir. Furthermore, our study shows that whole-rock Sr isotopic compositions could not represent the end-members and they may be a result of the assemblage of rock-forming minerals such as plagioclase with different initial Sr isotopic ratios. [ABSTRACT FROM AUTHOR]

The Cretaceous Yunshan caldera complex in SE China consists of an unusual coexisting assemblage of peraluminous and peralkaline rhyolites and a resurgent intra-caldera porphyritic quartz monzonite. In this study, we use zircon trace element data to study the compositional differences of zircons from cogenetic magmas and to track the evolution of the entire magmatic system. Our results indicate that the zircons from the peraluminous and peralkaline rhyolites formed from highly evolved compositions with high Hf concentrations and low Ti contents, and low Th/U and Zr/Hf ratios, which are distinct from those of the intrusive porphyritic quartz monzonite. Zircons from the peraluminous and peralkaline rhyolites display overlapping Zr/Hf and Hf, but the zircons from the peralkaline rhyolites have extremely low Eu/Eu* ratios (<0.1) and Ti contents (2.26–13.3 ppm). The lack of overlapping zircon trace element compositions between the volcanic and intrusive caldera units is interpreted to represent crystal–melt segregation processes. In addition, zircon grains from the porphyritic quartz monzonite and a few zircon grains from the peraluminous rhyolite display distinctly bright rims and whole grains in cathodoluminescence imaging, which have high Ti, Zr/Hf, and Eu/Eu*, and are similar to those of zircons from the mafic microgranular enclave within the porphyritic quartz monzonite. We interpret these signatures to reflect crystallization from a relatively hot and less evolved magma indicating a magma chamber recharge event. We further developed a model in which the magmas of the peraluminous and peralkaline rhyolites were successively extracted from a primitive crystal mush by crystal–melt segregation with a rejuvenation of the crystal mush after the extraction of the peraluminous rhyolitic melt, leaving behind residual mushes solidified as porphyritic quartz monzonite. Our study shows that trace element analyses of zircons can effectively be used to pinpoint multiple crystal–melt segregation and melt extraction events as well as magma recharge processes in silicic magmatic systems. • Volcanic-plutonic link was revealed by zircon trace elements from caldera complex. • Peralkaline rhyolite extracted from rejuvenated mush after peraluminous rhyolite extraction. • Contrasting compositions of volcanic and plutonic zircons imply crystal–melt segregation. • Multistage zircon crystallization reflects magma recharge processes. [ABSTRACT FROM AUTHOR]

Filling of the modern coastal-zone portion of the Qiantang River (QR) in eastern China was initiated by marine inundation during the transgression after the Last Glacial Maximum and has continued during the Holocene sea-level stillstand. The early part of the fi ll is transgressive in character, while the younger part is regressive. This paper deals with the sedimentary facies, surfaces, architecture, and depositional model of the QR incised-valley fi ll based on the detailed analysis of the newly drilled core SE2 and its correlation with more than 800 boreholes. The incised-valley deposits are grouped into fi ve stacked facies: amalgamated channel, floodplain and channel, paleo-estuary, offshore shallow marine, and present-day estuary. A paleo-estuary facies had never been identifi ed before, making these observations novel. This facies is characterized by a sedimentary succession and sediment distribution that are distinct from those of the present-day estuary because of a change in sediment supply from the sea fl oor beyond the estuary mouth. It also contains large numbers of tidal-channel sand bodies that are signifi cant reservoirs for shallow biogenic gas. Since the last glaciation, there have been three stages in the development of the QR incised-valley fi ll sequence: (1) a formation stage associated with sea-level fall, (2) a fi lling stage during the early transgression with rapid sea-level rise, and (3) a burial stage corresponding to the slowing of sea-level rise and the onset of progradation. This fill consists of four longitudinal segments, each of which is distinguished by a distinct stratigraphic succession and different degrees of marine and fluvial influence. The basal erosion surface and sidewalls of the incised valley, the top of stiff clay on the interfl uves, and the top of falling-stage fluvial-terrace deposits compose the sequence boundary. The initial flooding surface and maximum flooding surface are located with in the amalgamated channel and offshore shallow-marine sediments, respectively. These observations indicate that: (1) relative sea-level changes determine the stratal stacking patterns, but local environmental factors, such as physical processes, accommodation, sediment supply, and coastal confi guration control the nature of the facies, surfaces, and sediment-distribution patterns; and (2) the tripartite facies organization and wave ravinement surfaces typifying wavedominated or mixed-energy (wave and tide) incised-valley fi lls are absent in the macrotidal QR succession, and the tidal ravinement and erosion surfaces of the macrotidal QR incised valley are more extensive and numerous than those of the wave-dominated or mixed-energy succession. [ABSTRACT FROM AUTHOR]

Background: Hemorrhagic fever with renal syndrome (HFRS) is a rodent-borne disease caused by Hantaviruses. It is endemic in all 31 provinces, autonomous regions, and metropolitan areas in mainland China where human cases account for 90% of the total global cases. Shandong Province is among the most serious endemic areas. HFRS cases in Shandong Province were first reported in Yutai County in 1968. Since then, the disease has spread across the province, and as of 2005, all 111 counties were reported to have local human infections. However, causes underlying such rapid spread and wide distribution remain less well understood. Methods and Findings: Here we report a spatiotemporal analysis of human HFRS cases in Shandong using data spanning 1973 to 2005. Seasonal incidence maps and velocity vector maps were produced to analyze the spread of HFRS over time in Shandong Province, and a panel data analysis was conducted to explore the association between HFRS incidence and climatic factors. Results show a rapid spread of HFRS from its epicenter in Rizhao, Linyi, Weifang Regions in southern Shandong to north, east, and west parts of the province. Based on seasonal shifts of epidemics, three epidemic phases were identified over the 33-year period. The first phase occurred between 1973 and 1982 during which the foci of HFRS was located in the south Shandong and the epidemic peak occurred in the fall and winter, presenting a seasonal characteristic of Hantaan virus (HTNV) transmission. The second phase between 1983 and 1985 was characterized by northward and westward spread of HFRS foci, and increases in incidence of HFRS in both fall-winter and spring seasons. The human infections in the spring reflected a characteristic pattern of Seoul virus (SEOV) transmission. The third phase between 1986 and 2005 was characterized by the northeast spread of the HFRS foci until it covered all counties, and the HFRS incidence in the fall-winter season decreased while it remained high in the spring. In addition, our findings suggest that precipitation, humidity, and temperature are major environmental variables that are associated with the seasonal variation of HFRS incidence in Shandong Province. Conclusions: The spread of HFRS in Shandong Province may have been accompanied by seasonal shifts of HTNV-dominated transmission to SEOV-dominated transmission over the past three decades. The variations in HFRS incidence were significantly associated with local precipitation, humidity, and temperature. [ABSTRACT FROM AUTHOR]