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Fluid inclusions hidden in coesite-bearing zircons from ultrahigh-pressure metamorphic rocks in southwestern Sulu terrane, eastern China

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Fluid inclusions hidden in coesite-bearing zircons from ultr...

2004年全国岩石学与地球动力学研讨会

作者： LIU Fulai, xu Zhiqin institute of geology, chinese academy of Geological {5., {5. 100087, China

Primary fluid inclusions, together with coesite mineral inclusions, are identified in the same zircon domains by Laser Raman spectroscopy, cathodoluminescence (CL) image and micro-texture analysis in paragneiss and retrogressive eclogite from the main drilling hole of chinese Continental Scientific Drilling Project, southwestem Sulu terrane. Most fluid inclusions are characterized by CO (gas) - HO (liquid) two-phase;a few by HO one-phase liquid inclusions. These features indicate that the eclogite and its country-rocks may not be located in the "dry system", but in the "Wet system" circumstance, when the Sulu terrane occurred ultrahigh-pressure metamorphism. The SHRIMP U-Pb dating suggests that the time for fluid and coesite inclusions trapped in metamorphic recrystallized zircon domains is about 230-236 Ma (the weighted mean = 233.7±4.3 Ma);this age is in agreement with many reported Triassic UHP metamorphic ages of 230-245.Ma from eclogites and gneissic rocks in Sulu-Dabie terrane. This research not only shows important significance for an in-depth study of the fluid property and evolutional feature, and fluid-rock interaction mechanism in Sulu-Dabie UHP terrane, but also provides a new method for exactly identifying the primary fluid inclusions preserved in zircons from the ultrahigh-pressure metamorphic rocks in the world.

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Mapping forest fire risk zones with spatial data and principal component analysis

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Science China(Technological sciences) 2006年第z1期49卷 140-149页

作者： xu Dong, Guofan Shao, DAI Limin, HAO Zhanqing, TANG Lei & WANG Hui institute of Applied Ecology, chinese academy of sciences, Shenyang 110016, China Graduate University of chinese academy of sciences, beijing 100039, China Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA Department of Management, Shenyang institute of Aeronautical Engineering, Shenyang 110034, China Department of City Development, Jinan University, Jinan 25.002, China 1. institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China2. Graduate University of Chinese Academy of Sciences Beijing 100039 China3. Department of Forestry and Natural Resources Purdue University West Lafayette IN 47907 USA4. Department of Management Shenyang Institute of Aeronautical Engineering Shenyang 110034 China5. Department of City Development Jinan University Jinan 250002 China

By integrating forest inventory data with remotely sensed data, new data layers for factors that affect forest fire potentials were generated for Baihe Forestry Bureau in Jilin Province of China. The principle component analysis was used to sort out the relationships between forest fire potentials and environmental factors. The classifications of these factors were performed with GIS, generating three maps: a fuel-based fire risk map, a topography-based fire risk map, and an anthropogenic-factor fire risk map. These three maps were then synthesized to generate the final fire risk map. The linear regression method was used to analyze the relationship between an area-weighted value of forest fire risks and the frequency of historical forest fires at each forest farm. The results showed that the most important factor contributing to forest fire ignition was topography, followed by anthropogenic factors.

关键词： wildfire risk, regression analysis, geographic information system, remote sensing, Baihe Forestry Bureau.

THE SCIENTIFIC PROGRESSES OF chinese CONTINENTAL SCIENTIFIC DRILLING （CCSD） PROJECT: AN OVERVIEW

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THE SCIENTIFIC PROGRESSES OF CHINESE CONTINENTAL SCIENTIFIC ...

2004年全国岩石学与地球动力学研讨会

作者： xu Zhiqin (Laboratory of Continental dynamics, institute of geology, chinese academy of Geological {5., {5., 100037 )

＜正＞ By employing modern deep drilling techniques, chinese Continental Scientific Drilling Project （CCSD） is going to drill a 5.00 m deep hole at the Sulu ultra-high pressure metamorphic belt. The scientific objective is to reveal the 3-D deep materials constitutions of convergent plate margins, to improve our understanding of questions with regard to the physical and chemical processes that are responsible for the formation and evolution of UHP metamorphic terrains worldwide and finally to establish a deep laboratory for long term observation of present crustal activities.

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川东二叠纪生物礁的再认识

石油与天然气地质 2002年第1期23卷 12-18页

作者：范嘉松吴亚生中国科学院地质与地球物理研究所北京100029

通过川东 8口二叠纪长兴期钻井岩芯剖面的详细研究 ,铁山 5.、天东 10井代表典型的礁相剖面 ;板东 4井、双 15.既有礁相沉积 ,且有棘屑滩沉积 ;卧 117井、黄龙 1井以及云安 14井基本上由碳酸盐台地沉积组成 ;池 2 4井出现两种类型的礁... 详细信息

通过川东 8口二叠纪长兴期钻井岩芯剖面的详细研究 ,铁山 5.、天东 10井代表典型的礁相剖面 ;板东 4井、双 15.既有礁相沉积 ,且有棘屑滩沉积 ;卧 117井、黄龙 1井以及云安 14井基本上由碳酸盐台地沉积组成 ;池 2 4井出现两种类型的礁相 :海绵骨架礁和海绵障积礁。川东礁相剖面中的白云岩以海水与淡水混合作用而成的白云石化为主导因素 ,但它们在深埋阶段以后 ,又遭受后期白云石化的叠加 ,因此表现出许多深埋白云石化的地化特征。白云岩的原始沉积既可能是礁骨架岩 ,也可能是棘屑滩 ,甚至是碳酸盐台地沉积。因此在寻找礁型白云岩储层时。

关键词：油气地质生物礁二叠纪川东钻井岩芯

Rb-Sr chronological characteristics of Jurassic granitoid gravels in north margin of Dabie block,Central China

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Rb-Sr chronological characteristics of Jurassic granitoid gr...

中国科学院地质与地球物理研究所2001学术年会

作者： LI Zhong,LI Renwei,SUN Shu & ZHANG Wenhua institute of geology and geophysics,chinese academy of {5., beijing 1.0029,China

Granitoid gravels are discovered from alluvial fan conglomerates,the base of Jurassic Fenghuangtai Formation (J),in the north margin of Dabie block and the south part of the Hefei *** granitoid gravels make up 5.—10%of all gravels by volume percent For the four components,K-feldspar,biotite,amphibole and whole rock divided from two selected granitoid gravel samples,their Rb-Sr isotopes are measured,which gives two formation ages of granitoids:(428±20) Ma and(430±5.) Ma,and means that the Early Paleozoic granitoid intrusive rocks once existed in the Dabie Mountain provenances of *** granitoids occur in the tectonic setting of post-collision uplift according to lithogeochemical discriminant analysis.

关键词： Dabie block Hefei Basin granitoid gravels Rb-Sr isotope chronology depositional provenance

A thinned lithospheric image of the Tanlu Fault Zone,eastern China:Constructed from wave equation based receiver function migration

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A thinned lithospheric image of the Tanlu Fault Zone,eastern...

中国科学院地质与地球物理研究所2006学术年会

作者： Ling Chen,Tianyu Zheng,and Weiwei xu Seismological Laboratory(SKL-LE),institute of geology and geophysics,chinese {5. of {5.,beijing 1.0029,PR China

We apply the newly proposed wave equation-based receiver function poststack migration method to the Northern China interior Structure Project broadband data to image the lithospheric structure of the Tanlu Fault Zone area in eastern *** migration result reveals a 60- to 80-km-thick present-day lithosphere beneath the study region,significantly thinned from the Paleozoic lithosphere of >180 *** lithosphere asthenosphere boundary(LAB) is coherently imaged along the 00-km east-west profile,displaying an arc-like shape with its apex roughly coincident with the transverse location of the Tanlu Fault Zone on the *** obvious uplift from6 km to2 km of the Moho is also clearly detected right below this fault *** coincidence of the imaged Moho uplift and the LAB apex with the surface location of the Tanlu Fault Zone provides seismological evidence for the steep geometry and deep penetration of the fault system,and indicates that the Tanlu Fault Zone might have acted as a major channel for anthenosphere upwelling during the Mesozoic-Cenozoic continental extension and lithospheric thinning in eastern *** analysis and synthetic modeling suggest that both the Moho and the LAB are sharp and *** latter,in particular,is constrained to have a 3-7%drop in S wave velocity over a depth range of 10 km or *** a rapid velocity change at the base of the lithosphere in the study region cannot be solely explained by thermal variation,but likely reflects the presence of volatiles or melt in the asthenosphere,or is partially attributed to the compositional contrast between the preserved depleted and dehydrated cratonic lithospheric veneer and the uplifted hydrated and fertile asthenospheric materials.

关键词： Tanlu Fault Zone Receiver function Migration Lithosphere thinning

Challenges and opportunities in Quaternary palynology

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Science China Earth sciences 2024年第7期67卷 2148-2161页

作者： Qinghai xu Houyuan LU Zhuo ZHENG College of Geographical sciences Hebei Key Laboratory of Environmental Change and Ecological ConstructionHebei Normal UniversityShijiazhuang 050024China Key Laboratory of Cenozoic geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China School of Earth sciences and Engineering Sun Yat-sen UniversityZhuhai 519082China

Quaternary palynology plays a pivotal role in investigating global climate change and various other research fields,serving as an essential tool for the quantitative analysis of paleoenvironment ***,due to the vast diversity of terrestrial ecosystems and intricate interactions between vegetation,climate,and human activities,further advancements are required in the following aspects within this discipline.(1)The accuracy of classification in pollen morphology and fossil pollen identification needs improvement,particularly at the species *** represents a significant challenge in present Quaternary ***-aided intelligent recognition holds promise as a solution for species identification based on more detail pollen morphology.(2)Most pollen-based vegetation and climate reconstructions overlook the significance of bare *** bare ground can lead to substantial inaccuracies when quantitatively reconstructing past vegetation and climate.(3)While pollen records provide reliable information on paleoclimate changes,current quantitative climate reconstruction models heavily rely on modern pollen datasets derived from present-day vegetation disturbed more or less by human *** introduces bias and uncertainties into paleoclimate reconstruction.(4)Although pollen can serve as an indicator of human activities,accurately quantifying the intensity of human influence remains *** accurate identification of crop pollen,reconstructing reliable land cover/use data,and integrating multidisciplinary data may enhance the identification and quantification of signals related to human activity in pollen records.

关键词： Quaternary palynology Paleoclimate Paleovegetation Human activity

Preliminary Response of Soil Fauna to Simulated N Deposition in Three Typical Subtropical Forests

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Pedosphere 2006年第5期16卷 596-601页

作者： xu Guo-Liang MO Jiang-Ming ZHOU Guo-Yi FU Sheng-Lei institute of Ecology South China Botanical Garden Chinese Academy of Sciences Guangzhou 510650 （China） Graduate School of the chinese academy of sciences Beijing 100039 （China）

A field-scale experiment arranged in a complete randomized block design with three N addition treatments including a control (no addition of N), a low N (5.g m-2 year-1), and a medium N (10 g m-2 year-1) was performed in each of the three typical forests, a pine (Pinus massoniana Lamb.) forest (PF), a pine-broadleaf mixed forest (MF) and a mature monsoon evergreen broadleaf forest (MEBF), of the Dinghushan Biosphere Reserve in subtropical China to study the response of soil fauna community to additions of N. Higher NH4+ and NO3- concentrations and a lower soil pH occurred in the medium N treatment of MEBF, whereas the NO3- concentration was the lowest in PF after the additions of N. The response of the density, group abundance and diversity index of soil fauna to addition of N varied with the forest type, and all these variables decreased with increasing N under MEBF but the trend was opposite under PF. The N treatments had no significant effects on these variables under MF. Compared with the control plots, the medium N treatment had significant negative effect on soil fauna under MEBF. The group abundance of soil fauna increased significantly with additions of higher N rates under PF. These results suggested that the response of soil fauna to N deposition varied with the forest type and N deposition rate, and soil N status is one of the important factors affecting the response of soil fauna to N deposition.

关键词： Dinghushan Biosphere Reserve N deposition soil fauna subtropical China

East Asian monsoon instability at the stage 5./4 transition

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East Asian monsoon instability at the stage 5a/4 transition

中国科学院地质与地球物理研究所2002学术年会

作者： SHANGFA XIONG,ZHONGLI DING,TUNGSHENG LIUAND JINGZHAO ZHANG institute of geology and geophysics,chinese academy of {5.,1.0029 beijing,China

The physics involved in the abrupt climate changes of the late Quaternary have eluded paleoclimatologists for many *** paleoclimatic records characteristic of different elements of the global climate system are needed for better understanding of the cause-feedback relationships in the *** East Asian monsoon is an important part of the global climate system and the mechanical linds between the East Asian monsoon and other climatic elements around the world may hold a key to our knowledge of abrupt climate changes in East Asia and probably over a larger part of the *** studies have detected millennial-scale winter monsoon oscillations during the last glaciation and probably also during the last interglaciation in loess sequences across China. However,less attention has been paid to the abrupt summer monsoon changes and the stage 5./4 transition,an important period for the evolution of the East Asian monsoon when the global climate shifted torards the last *** we report on two loess sections from eastern China which were dated using a thermoluminescence(TL) *** pedogenic and other sediment parameters suggest that the summer monsoon experienced a two-step abrupt retreat at the stage 5./4 *** variations in the proxies for the winter monsoon are synchronized with the summer monsoon proxies during this brief *** a direct and immediate lin between high latitude and low latitude *** changes may be correlated with similar climatic oscillations observed in the North Atlantic,Europe and Antarcica,raising the possibility that the forcing factors that induced these changes are global in extent.

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