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NanoSIMS analytical technique and its applications in earth sciences

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Science China earth sciences 2015年第9期58卷 1758-1767页

作者： YANG Wei HU Sen ZHANG JianChao HAO JiaLong LIN YangTing Key Laboratory of earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences

Despite the significant improvement on spatial resolution, NanoSIMS still preserves relatively high mass resolution, sensitivity, and analytical precision. It has become an important analytical platform to determine chemical compositions of solid materials, and has been widely used in space, earth, life, and materials sciences, etc. By using a Cs＋ ion beam with a size as small as 50 nm scanning over sample surfaces, we are able to obtain high spatial resolution images of up to 7 species simultaneously. When utilizing Faraday cup, high analytical precision of 0.3‰-0.5‰ （1SD） for C, O and S isotopic analysis can be achieved. Although this precision level is still lower than that of conventional SIMS, it already meets the major requirements of earth sciences. In 2011, the first NanoSIMS of China （Cameca NanoSIMS 50L） was installed at institute of Geology and Geophysics, Chinese Academy of sciences. Based on the working mechanism and analytical modes of the instrument, this paper will systematically introduce the analytical methods established with the NanoSIMS and their potential applications in earth sciences. These methods include trace element distribution images in mineral zoning, high spatial resolution （2-5/am） Pb-Pb and U-Pb dating, water content and H isotopic analysis for silicate glass and apatite, C isotopic analysis for diamond and graphite, O isotopic analysis for carbonate, S isotopic analysis for sulfides. In addition, the specific requirements for sample preparation will also be introduced in order to facilitate domestic earth scientists＇ use.

关键词： NanoSIMS micro-beam analysis elemental distribution images Pb-Pb and U-Pb dating stable isotopes

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Impacts of the annual cycle of background SST in the tropical Pacific on the phase and amplitude of ENSO

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Atmospheric and Oceanic Science Letters 2025年第01期 14-19页

作者： Song Jiang Congwen Zhu Ning Jiang State Key Laboratory of Severe Weather (LASW) Chinese Academy of Meteorological Sciences College of earth and Planetary sciences University of Chinese Academy of Sciences

基于1982–2022年资料分析,本文发现,热带太平洋海温年循环的主导模态为反对称模式,是ENSO发展的背景场.然而,其对ENSO相位和振幅的异常影响尚未可知.反对称模态异常可以通过Bjerknes反馈影响ENSO的年际变化,其正(负)异常可以通过更早(... 详细信息

基于1982–2022年资料分析,本文发现,热带太平洋海温年循环的主导模态为反对称模式,是ENSO发展的背景场.然而,其对ENSO相位和振幅的异常影响尚未可知.反对称模态异常可以通过Bjerknes反馈影响ENSO的年际变化,其正(负)异常可以通过更早(更晚)的季节循环转变时间和更大(更小)的年平均值增强冬季El Ni?o (La Ni?a)的强度.根据随机敏感性实验分析,与反对称模态变化有关的赤道中东太平洋海温异常可达±0.3℃以上.研究结果为背景海温年循环对ENSO的影响提供了新的见解,这可能对ENSO的预测具有重要意义.

关键词：年循环海表面温度异常反对称模态 ENSO

Modeling the Middle Jurassic ocean circulation

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Journal of Palaeogeography 2015年第4期4卷 373-386页

作者： Maura Brunetti Christian Vérard Peter O.Baumgartner institute for Environmental sciences University of Geneva institute of earth sciences University of Lausanne

We present coupled ocean-sea-ice simulations of the Middle Jurassic（~165 Ma） when Laurasia and Gondwana began drifting apart and gave rise to the formation of the Atlantic Ocean. Since the opening of the Proto-Caribbean is not well constrained by geological records, configurations with and without an open connection between the Proto-Caribbean and Panthalassa are examined. We use a sea-floor bathymetry obtained by a recently developed three-dimensional（3D） elevation model which compiles geological, palaeogeographical and geophysical data. Our original approach consists in coupling this elevation model, which is based on detailed reconstructions of oceanic realms, with a dynamical ocean circulation model. We find that the Middle Jurassic bathymetry of the Central Atlantic and Proto-Caribbean seaway only allows for a weak current of the order of 2 Sv in the upper 1000 m even if the system is open to the West. The effect of closing the western boundary of the Proto-Caribbean is to increase transport related to barotropic gyres in the southern hemisphere and to change water properties, such as salinity, in the Neo-Tethys. Weak upwelling rates are found in the nascent Atlantic Ocean in the presence of this superficial current and we discuss their compatibility with deep-sea sedimentological records in this region.

关键词： Jurassic modeling ocean circulation palaeoclimate

Water mass characteristics in the western North Pacific based on a streamfunction projection

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Science China earth sciences 2015年第11期58卷 2067-2077页

作者： MA Xiao SUN Che institute of Oceanology Chinese Academy of Sciences College of earth sciences University of Chinese Academy of Sciences

A streamfunction projection method called gravest empirical mode(GEM) is applied to the hydrographic section at 137°E to filter out eddy noises in the western North Pacific and derive quantitative ensemble-average water mass properties in the North Equatorial Current region. The GEM fields capture more than 80% of total property variances in the thermocline layer. The core layer structures of key water masses, including the North Pacific Tropical Water(NPTW) and the North Pacific Intermediate Water(NPIW), are examined with a definition of water mass boundary based on property gradient. It shows that a tongue of maximal root-mean-square(RMS) residual exists in the upper half of NPIW for all water properties. These subsurface RMS tongues appear to be close to sharp property gradients. It is the first time a GEM diagnosis is applied to nutrient data, which reveals a drastic difference of N/P reaction rate ratio above and below the maximal-nutrient core at 1250 m. Additionally, a GEM velocity reconstruction successfully produces the North Equatorial Undercurrent(NEUC), demonstrating the stable thermal-wind nature of this newly-discovered current.

关键词： streamfunction projection gravest empirical mode water masses western North Pacific

Enveloping Relief Surfaces of Landslide Terrain

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Journal of Mountain Science 2007年第3期4卷 203-208页

作者： A.K.Pachauri Abhirup Chatterjee Reeta Gaur Department of earth sciences Indian Institute of Technology

Two relief surfaces that envelop the rock fall region in a part of Garhwal Himalayas around Chamoli have been identified. Relative relief and absolute relief have been analyzed and the enveloping surfaces recorded at two levels of relief in the landscape. All landslide activity lies within these surfaces. The lower enveloping surface （800 m） dips due south by 7-8 degrees, due to an elevation rise of lOO meters within 12 km from south to north, i.e., a gradient of 8 percent. The nature of the surface is smooth. The upper enveloping surface （〉 2500 m） is almost parallel to the lower one but its surface is undulatory due to landslides and denudation. The area has been a seismically active region and has undergone seismic activity up until recently, as evidenced by the Chamoli earthquake of 29th March 1999. The effects of earthquakes are seen at higher levels in the form of landslide imprints on the terrain.

关键词： Relief landslide terrain Himalayas

Early Cretaceous Magma Mingling in Xiaocuo,Southeastern China Continental Margin:Implications for Subduction of Paleo-Pacific Plate

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Acta Geologica Sinica(English Edition) 2016年第5期90卷 1713-1742页

作者： ZHOU Liyun WANG Yu HEI Huixin ZHOU Xiaohui institute of earth sciences China University of GeosciencesBeijing Department of earth and Environmental sciences University of Waterloo

Magma mingling has been identified within the continental margin of southeastern *** study focuses on the relationship between mafic and felsic igneous rocks in composite dikes and plutons in this area,and uses this relationship to examine the tectonic and geodynamic implications of the mingling of mafic and felsic *** magmatic enclaves（MMEs） show complex relationships with the hosting Xiaocuo granite in Fujian area,including lenticular to rounded porphyritic microgranular enclaves containing abundant felsic/mafic phenocrysts,elongate mafic enclaves,and back-veining of the felsic host granite into mafic ***-ICP-MS zircon U-Pb analyses show crystallization of the granite and dioritic mafic magmatic enclave during ca.132 and 116 *** host granite and MMEs both show zircon growth during repeated thermal events at-210 Ma and 160-180 *** from the magma mingling zone generally contain felsic-derived zircons with well-developed growth zoning and aspect ratios of 2-3,and maficderived zircons with no obvious oscillatory zoning and with higher aspect ratios of ***,these two groups of zircons show no obvious trace element or age *** Hf-isotope compositions show that the host granite and MMEs have similar ε（Hf）（t） values from negative to positive which suggest a mixed source from partial melting of the Meso-Neoproterozoic with involvement of enriched mantlederived magmas or juvenile *** lithologies,mineral associations,and geochemical characteristics of the mafic and felsic rocks in this study area indicate that both were intruded together,suggesting Early Cretaceous mantle—crustal interactions along the southeastern China continental *** Early Cretaceous magma mingling is correlated to subduction of Paleo-Pacific plate.

关键词： magma mingling mafic and felsic magma zircon U-Pb ages zircon Hf isotopes southeastern China continental margin

Big earth Data from space: a new engine for earth science

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Science Bulletin 2016年第7期61卷 505-513页

作者： Huadong Guo Lizhe Wang Dong Liang institute of Remote Sensing and Digital earth Chinese Academy of Sciences

Big data is a strategic highland in the era of knowledge-driven economies, and it is also a new type of strategic resource for all nations. Big data collected from space for earth observation—so-called Big earth Data—is creating new opportunities for the earth sciences and revolutionizing the innovation of methodologies and thought patterns. It has potential to advance in-depth development of earth sciences and bring more exciting scientific *** Academic Divisions of the Chinese Academy of sciences Forum on Frontiers of Science and Technology for Big earth Data from Space was held in Beijing in June of *** forum analyzed the development of earth observation technology and big data, explored the concepts and scientific connotations of Big earth Data from space, discussed the correlation between Big earth Data and Digital earth, and dissected the potential of Big earth Data from space to promote scientific discovery in the earth sciences, especially concerning global changes.

关键词： Big data Big earth Data from spaceDigital earth earth sciences earth observation Scientific big data Data-intensive science

Equatorial aurora: the aurora-like airglow in the negative magnetic anomaly

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National Science Review 2020年第10期7卷 1606-1615页

作者： Fei He Yong Wei Weixing Wan Key Laboratory of earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences College of earth and Planetary sciences University of Chinese Academy of Sciences

The most fantastic optical phenomena in the earth’s upper atmosphere are the auroras. They are highly informative indicators of solar activity, geomagnetic activity, upper atmospheric structures and dynamics,and magnetospheric energetic particles. An area where the geomagnetic field differs significantly from the expected symmetric dipole, such as at the South Atlantic Anomaly, where the magnetic field intensity is low,gives rise to stronger precipitation of energetic particles into the upper atmosphere. Impact excitation and the subsequent airglow emissions exhibit aurora-like dynamic signatures. Nomenclatures of nonpolar aurora or equatorial auroras are similar to those used with the polar auroras owing to their similar excitation mechanisms. This paper provides an overview of the knowledge and the challenges concerning auroral activity at the South Atlantic Anomaly, or more generally, at the negative magnetic anomaly. We emphasize systematic investigation of the equatorial auroras to reveal the temporal and spatial evolution of the magnetic anomaly and the behaviour of energetic particles in near-earth space.

关键词： aurora geomagnetic field South Atlantic Anomaly negative magnetic anomaly energetic particles

On the origin of microbial magnetoreception

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National Science Review 2020年第2期7卷 472-479页

作者： Wei Lin Joseph L.Kirschvink Greig A.Paterson Dennis A.Bazylinski Yongxin Pan Key Laboratory of earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences Institutions of earth Science Chinese Academy of Sciences France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms Chinese Academy of Sciences Division of Geological & Planetary sciences California Institute of Technology earth-Life Science institute Tokyo Institute of Technology Department of earth Ocean and Ecological Sciences University of Liverpool School of Life sciences University of Nevada at Las Vegas College of earth and Planetary sciences University of Chinese Academy of Sciences

A broad range of organisms, from prokaryotes to higher animals, have the ability to sense and utilize earth’s geomagnetic field—a behavior known as magnetoreception. Although our knowledge of the physiological mechanisms of magnetoreception has increased substantially over recent decades, the origin of this behavior remains a fundamental question in evolutionary biology. Despite this, there is growing evidence that magnetic iron mineral biosynthesis by prokaryotes may represent the earliest form of biogenic magnetic sensors on earth. Here, we integrate new data from microbiology, geology and nanotechnology, and propose that initial biomineralization of intracellular iron nanoparticles in early life evolved as a mechanism for mitigating the toxicity of reactive oxygen species(ROS), as ultraviolet radiation and free-iron-generated ROS would have been a major environmental challenge for life on early earth. This iron-based system could have later been co-opted as a magnetic sensor for magnetoreception in microorganisms, suggesting an origin of microbial magnetoreception as the result of the evolutionary process of exaptation.

关键词： magnetoreception biomineralization magnetotactic bacteria exaptation