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Xing L.,China University of GeosciencesBeijing | McKellar R.C.,Royal Saskatchewan Museum | McKellar R.C.,University of Regina | Xu X.,CAS Institute of Vertebrate Paleontology and Paleoanthropology | And 12 more authors.
Current Biology | Year: 2017

In his correspondence, Markus Lambertz [1] raises some concerns about the phylogenetic placement and feather development of DIP-V-15103, the amber-entombed tail section that we recently reported [2] as fragmentary remains of a non-pygostylian coelurosaur (likely within the basal part of Coelurosauria). We here would like to respond to these concerns. © 2017 Elsevier Ltd

Zhang H.F.,China University of GeosciencesBeijing | Wang H.Z.,CAS Institute of Geology and Geophysics | Dou J.Z.,China University of GeosciencesBeijing | Zhang S.Y.,China University of GeosciencesBeijing
Acta Petrologica Sinica | Year: 2015

Trondhjemite, Tonalite and Cranodiorite (TTG) as dominated lithological assemblages in Archean high-grade metamorphic terranes can provide important clues for the history and mechanism of crustal growth. However, their genesis is still debated. The Huai'an terrane located in the north-central region of the North China Craton, is mainly composed of Archean gray gneisses, which are dominated by TTG rocks. The Huai'an TTG are predominantly tonalite with minor trondhjemite and granodiorite. Previously, we recognized some Low - Al trondhjemites from the Huai'an gray gneisses with pronounced negative Eu anomalies and enriched heavy rare earth elements (REE) as well as high SiO2 contents. Zircon SHRIMP U-Pb dating yielded a formation age of 2.53Ga, indicating their coeval magmas with the widespread High-Al TTGs, regionally. This work provides new data from Low-Al and High-Al TTGs to give a detailed investigation on their petrogenesis. As a result, the Low-Al trondhjemites are enriched in SiO2 (76% ∼ 79%), with low Al2O3(11.01% ∼ 12.61%), CaO(1.27% ∼ 1.59%), MgO (0.74% ∼ 0.24%) contents and highly variable Mg#(18 ∼ 53). In contrast, major elements of the High-Al TTGs vary largely, for example, SiO2 is between 63% ∼ 77%, Al2O3 is 13.2% ∼ 17.77%, CaO is 1.8% ∼ 5.78%, MgO is 0.18% ∼ 3.84%, and Mg# is 35 ∼ 64. In addition, the Low-Al trondhjemites exhibit pronounced negative Eu anomalies (Eu/Eu∗is 0.59 ∼ 0.44) and enriched heavy REE ((La/Yb)N=4 ∼ 7, (Gd/Yb)N=0.36 ∼ 1.27), whereas the High-Al TTGs show slightly negative to pronounced positive Eu anomalies (Eu/Eu∗=0.8 ∼ 5.35) and relatively low heavy REE ((La/Yb)N=10 ∼ 103, (Gd/Yb)N=1.97 ∼ 5.72). In primitive mantle normalized spidergrams, the Low-Al trondhjemites are depleted in Sr and Ba, while the High-Al tonalites are enriched in the elements. Lu/Hf ratios of the Low-Al trondhjemite (0.10 ∼ 0.16) are relatively higher than those of the High-Al rocks (0.01 ∼ 0.07), indicating that they have different sources and petrogenesis. Based on a combination of zircon U-Pb and Lu-Hf isotopes and whole-rock geochemistry, we consider that the Low-Al trondhjemitic magma was derived by partial melting of juvenile crust leaving a residue composed of pyroxene and plagioclase, without or with minor amphibole, and experienced the crystallization of monazite en route. The High-Al TTGs were generated by partial melting of juvenile crust at relatively high pressure with a residual mineral assemblage of garnet, amphibole, pyroxene and minor plagioclase, and the magma experienced fractional crystallization of hornblende and clinopyroxene with some extent of feldspar accumulation. It is proposed that the Huai' an TTGs were generated by anatexis of lower crust at various depths as a consequence of the Late Archean mantle plume activity or the combined effect of mantle plume and slab subduction.

Wang H.Z.,CAS Institute of Geology and Geophysics | Wang H.Z.,University of Chinese Academy of Sciences | Zhang H.F.,China University of GeosciencesBeijing | Zhai M.G.,CAS Institute of Geology and Geophysics
Acta Petrologica Sinica | Year: 2015

Metamorphism history of high-grade metamorphic rocks is an important clue to shed light on crust tectono-thermal events. However, intra-crystalline diffusion and recrystallization induced element re-distribution between rock-forming minerals, which have important influence on inversion of peak metamorphic history. On the contrary, intra-crystalline diffusion rates of trace elements are relatively slower than those of the major elements. Therefore, trace elements distribution and partition patterns in rock-forming minerals might be useful tools to shed light on metamorphic history of mafic high-pressure granulites. Major and trace elements of major rock-forming minerals in mafic high-pressure granulite are analyzed by in-situ LA-ICP-MS measurement to learn about trace element redistribution patterns between minerals and their indication of metamorphism. Our results show major elements (Mg, Fe, Ca) in peak stage minerals including garnet, clinopyroxene and plagioclase are homogenized by diffusion and recrystallization distribution, so P-T condition in peak stage can't get good inversion through minerals thermobarometry, but rare earth elements and trace elements distributed in garnet and clinopyroxene as bell shape to infer peak history recorded by trace elements and REE. Compiling major element thermobarometry and trace element thermometer results, we estimate P-T conditions of the peak and retrograde metamorphism of > 828°C and 1.27GPa, 810 ∼ 840°C and 0.6 ∼ 1.0GPa, respectively. Deduced amphibolite facies metamorphism took place after retrograde medium pressure granulite metamorphism. Integreting with previous data, we suggest that our mafic granulite experienced an ITD metamorphic history.

Huang S.,University of the Humanities | Huang S.,Key Laboratory of Carrying Capacity Assessment for Resource and Environment | An H.,University of the Humanities | An H.,Key Laboratory of Carrying Capacity Assessment for Resource and Environment | And 5 more authors.
Physica A: Statistical Mechanics and its Applications | Year: 2016

The nonlinear relationships among variables caused by the hidden frequency information complicate the time series analysis. To shed more light on this nonlinear issue, we examine their relationships in joint time-frequency domain with multivariate framework, and the analyses in the time domain and frequency domain serve as comparisons. The daily Brent oil prices, London gold fixing price and Shanghai Composite index from January 1991 to September 2014 are adopted as example. First, they have long-term cointegration relationship in time domain from holistic perspective. Second, the Granger causality tests in different frequency bands are heterogeneous. Finally, the comparison between results from wavelet coherence and multiple wavelet coherence in the joint time-frequency domain indicates that in the high (1-14 days) and medium frequency (14-128 days) bands, the combination of Brent and gold prices has stronger correlation with the stock. In the low frequency band (256-512 days), year 2003 is the structure broken point before which Brent and oil are ideal choice for hedging the risk of the stock market. Thus, this paper offers more details between the Chinese stock market and the commodities markets of crude oil and gold, which suggests that the decisions for different time and frequencies should consider the corresponding benchmark information. © 2015 Elsevier B.V.

Chen D.Y.,China University of GeosciencesBeijing | Chen J.P.,China University of GeosciencesBeijing | Wang Q.,Zijin Mining Group Co. | Li C.F.,China University of GeosciencesBeijing | And 2 more authors.
Acta Petrologica Sinica | Year: 2015

The Zhongtiao-Yuxi area is located in the southern part of the North China Craton. The area experienced the most intensely multi-stage tectono-magmatic events during the Precambrian, including Neoarchean-Early Paleoproterozoic (2550 ∼ 2350Ma) crustal growth, Paleoproterozoic (2350 ∼ 1850Ma) rifting-subduction-accretion-collision, and Early Mesoproterozoic (1800 ∼ 1600Ma) extension. The geological events caused tectonic stress field varied and contributed to numerous structure faults in different structure layers. It is believed that the development of structural faults was younger than the stratigraphic units which were cut through by the structural faults, and the development of structural faults was older than the stratigraphic units which were not cut through by the structural faults. Here we make a analysis of tectonic evolution to extract structure features of different structure layers using GIS-based approach, combined with faults of style, size, orientation and strength and the features of structure construction. A three-step process has been proposed in this study as follows: (1) Extracting the structure faults confined in Neoarchean-Early Mesoproterozoic stratigraphic units. They represented the main structure features during the Precambrian. (2) Translating the unconformities into mappable features using Geographic Information System (GIS) to determine the main structure features during Ar-Pt2. Statistics on strike and length of fault structures had been selected, it is confirmed that the NEE, sub-SN and NWW-trending structures were the main structural orientation. (3) Extracting the main structure faults of different structure layers based on the structural formations characteristics, and the region tectonic evolution. The main structural orientations of Neoarchean-Early Paleoproterozoic, Paleoproterozoic and Mesoproterozoic structure layers were the NE/NW, NEE/NWW, and sub-EW-strending, respectively.

Fang M.,Nanjing University | Ju W.,Nanjing University | Liu X.,China University of GeosciencesBeijing | Yu Z.,Hangzhou Normal University | And 2 more authors.
Terrestrial, Atmospheric and Oceanic Sciences | Year: 2015

This study examines the spatio-temporal variations in the sea-surface chlorophyll-a (Chl-a) concentration and their associated underlying driving forces in the northern South China Sea (SCS) from 2004 - 2010. A stratified analysis method and the Moderate Resolution Imaging Spectroradiometer (MODIS) Chl-a product, the National Centers for Environmental Prediction (NCEP) reanalysis data, with maps of monsoon winds and current systems were used in this work. Validation indicated that the MODIS-derived Chl-a is in good agreement with in-situ measurements (R2 = 0.815), accurate enough for analyzing the temporal-spatial variations of Chl-a in the northern SCS. The results show that the spatial heterogeneity of the Chl-a concentration was lowest in winter and increased in spring. The seasonal Chl-a concentration dynamics varied spatially and depended predominantly on the distance from the coastline. The most important factors that affect the Chl-a concentration spatial variability were identified as the monsoon, surface current and sea surface temperature (SST).

Dong F.,Chongqing Technology and Business University | Xiong T.,Chongqing Technology and Business University | Sun Y.,Chongqing Technology and Business University | Huang H.,China University of GeosciencesBeijing | Wu Z.,Zhejiang University
Journal of Materials Chemistry A | Year: 2015

A novel environmental catalyst, black defective (BiO)2CO3 microspheres, was prepared by a vacuum heat treatment method. It was interesting to discover that the as-obtained catalyst contained the Bi element phase, Bi5+ ions and oxygen defects. These components endowed the black (BiO)2CO3 microspheres with efficient catalytic performance in NO removal. In situ DRIFTS investigation demonstrated that the adsorbed NO molecules at the active sites (Bi0, Bi5+ and oxygen defects) could react with the O2 activated by oxygen defects to produce nitrogen dioxide, nitrite and nitrate in the dark. When visible light was applied, highly enhanced catalytic activity can be achieved. On one hand, the visible light was transformed to thermal energy, accelerating the thermocatalytic reaction. On the other hand, the visible light could directly initiate the photocatalysis reaction as the generated oxygen defects could narrow the band gap of (BiO)2CO3 and the plasmonic effect of the Bi element promoted the separation of electron-hole pairs. The highly efficient performance for NO removal under visible irradiation was correlated with the synergistic integration of thermocatalysis and photocatalysis. In addition, a facile method was developed to activate and regenerate the used catalyst for recycling application. This work could provide an innovative technology for NO removal by exploiting the synergistic integration of room temperature catalysis and visible photocatalysis and opens up new opportunities for the design of efficient and low-cost catalysts for air purification. This journal is © The Royal Society of Chemistry.

Zhang L.Y.,China University of GeosciencesBeijing | Liu S.A.,China University of GeosciencesBeijing | Zhao P.L.,China University of GeosciencesBeijing | Wang F.Y.,Hefei University of Technology
Acta Petrologica Sinica | Year: 2015

The origin of porphyry copper deposits in the Middle-Lower Yangtze River has been controversial for a long time. This paper aims to track the source of ore-bearing porphyries and associated mafic xenoliths by using high-precision Cu isotopic analysis of a series of Mesozoic plutons in the Ningzhen area. The results show a wide range of δ65 Cu of Anjishan dioritic porphyries from -0.13‰ to +0.36‰ and a homogeneous Cu isotopic composition of the gabbro xenoliths from +0.14‰ to +0.19‰. δ65 Cu of the Tongshan porphyries are in the range of +0.03‰ to +0.36‰, and gabbro xenoliths are from +0.10‰ to + 0.20‰. δ65 Cu of granodiorite in Xiangshan pluton is + 0.20‰ ± 0.06‰ and δ65 Cu value of the gabbro xenolith is + 0.16‰ ± 0.06‰. Overall, δ65 Cu values of porphyries from the three plutons exhibit a relatively large range; however, δ65 Cu of gabbro xenoliths cluster between +0.1‰ and +0.2‰, with an average value of +0.15‰ ± 0.05‰, consistent with the mantle value (+0.07‰ ± +0.10‰). Previous studies show that the ore-bearing porphyries in Ningzhen have high MgO, high Mg# values and low radiogenic Pb isotopic compositions, and that ancient lower crustal rocks commonly show variable Cu isotopic compositions. Thus, the genesis of the ore-bearing porphyries and the origin of copper in these deposits might be best explained by magma mixing between the magmas derived from metasomatized mantle and melts originated from old lower continental crust.

Dai C.,China University of Petroleum - East China | Wu X.,China University of Petroleum - East China | Li W.,China University of Petroleum - East China | You Q.,China University of GeosciencesBeijing | And 4 more authors.
Soft Matter | Year: 2015

To understand the role of electrostatic interactions and hydrogen bonds in the formation of wormlike micelles with the aid of sodium salicylate, two quaternary ammonium surfactants with the headgroup decorated by one hydroxyethyl group N-cetyl-N-(2-hydroxyethyl)dimethylammonium bromide and two hydroxyethyl groups N-cetyl-N,N-di(2-hydroxyethyl)methylammonium bromide, abbreviated as CHEMAB and CDHAB, respectively, were synthesized in this work. Single crystal X-ray diffraction was used to study the intermolecular interactions of surfactants, and 1H NMR and rheological measurements were employed to investigate the molecular arrangement and morphology of the wormlike micelles. The synergistic interactions of hydrogen bonding and more effective shielding of electrostatic repulsion contribute to the formation and viscoelastic behavior of wormlike micelles. The results also revealed the aggregation behavior of surfactants with hydroxyethyl headgroups in aqueous solutions. © The Royal Society of Chemistry.

Xu K.,China University of GeosciencesBeijing | Yu B.,China University of GeosciencesBeijing | Gong H.,China University of GeosciencesBeijing | Ruan Z.,China University of GeosciencesBeijing | And 2 more authors.
Geoscience Frontiers | Year: 2015

Abstract Oil and gas exploration in carbonate rocks was extremely successful in recent years in the Ordovician in Tarim Basin, NW China. Here, we investigate the carbonate reservoirs in the Bachu area of the Tarim Basin through petrological and geochemical studies combined with oil and gas exploration data. Geochemical analysis included the major, trace, and rare earth elements; fluid inclusion thermometry; clay mineral characterization; and carbon and oxygen isotopes of the carbonate rocks. Homogenization temperatures of the fluid inclusions of Well He-3 in the Bachu area indicate three groups, 60-80 °C, 90-130 °C, and 140-170 °C, and suggest that the carbonate rocks experienced modification due to heating events. The porosity in the reservoir is defined by fractures and secondary pores, and there is a notable increase in the porosity of the carbonate reservoirs in proximity to magmatic intrusion, particularly approximately 8-10 m from the intrusive rocks. The development of secondary pores was controlled by lithofacies and corrosion by various fluids. We identify supercritical fluids with high density (138.12-143.97 mg/cm3) in the Bachu area. The negative correlations of δ13C (-2.76‰ to -0.97‰) and δ18O (-7.91‰ to -5.07‰) suggest that the carbonate rocks in the study area were modified by high-salinity hydrothermal fluid. The formation of clay minerals, such as illite and montmorillonite, caused a decrease in porosity. Our study demonstrates the effect of magmatic intrusions in modifying the reservoir characteristics of carbonate rocks and has important implications for oil and gas exploration. © 2015 China University of Geosciences (Beijing) and Peking University.

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