检索结果-南通市图书馆

Carbon and Oxygen Stable Isotope Values and Microfossils at 4..4.4.5ka BP in Tai Co,Tibet,{3.,and Their Paleoclimatic Significance

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2011年第5期85卷 1036-1050+1052-1056+1051页

作者： ZHENG Mianping~(1,2.*),LIU Junying~(1,3.,MA Zhibang~(1,4.,WANG Hailei~(1,2. and MA Nina~(1,2. 1 MLR Key Laboratory of Saline Lake Resources and Environment,Institute of Mineral Resources,CAGS, beijing 10003.,{2. 2.Research and Development Center for Saline Lakes and Epithermal Deposits,chinese Academy of Geological Sciences,beijing 10003.,{2. 3.Institute of geology,chinese Academy of Geological Sciences,beijing 10003.,{2. 4.Key Laboratory of Cenozoic geology and Environment,chinese Academy of Sciences,beijing 10002., china MLR Key Laboratory of Saline Lake Resources and Environment Institute of Mineral Resources CAGS Beijing 100037 China Research and Development Center for Saline Lakes and Epithermal Deposits Chinese Academy of Geological Sciences Beijing 100037 China Institute of geology Chinese Academy of Geological Sciences Beijing 100037 China Key Laboratory of Cenozoic geology and Environment Chinese Academy of Sciences Beijing 100029 China *Correspondence: Mianping ZHENG *Correspondence: Corresponding author. E-mail: zhengmp2010@***

Two sedimentary sections were measured at Tai Co(Co means lake in Tibetan) in western Tibet,*** two sections are almost all composed of clay carbonate beds except in their lower parts where there are carbonized plants at>10 cm depths and dark-colored carbonate clay and clay at 50-70 cm depths,yielding abundant gastropods,ostracods,and *** carbon and oxygen stable isotope values of carbonate,ostracods,and charophytes and ecological features of microfossil communities indicate the following climatic change in the area from 4..4.to 4.5 ka BP:at 4..4.2..2.ka BP,the climate was relatively wet;at 2..2.2..5 ka BP,it was slightly warm-dry;at 2..5-2..5 ka BP,it was warm-wet;at 2..5-2..0 ka BP,it was slightly cold-wet;at 2..5-17.5 ka BP,it became cold abruptly and slightly wet,implying the climate of the last glacial maximum;at 17.5-16.0 ka BP,it was slightly cold-dry;at 16.0-11.8 ka BP,it was slightly warm-wet;at 11.8-10.4.ka BP,it was relatively cold-dry, roughly equivalent to the climate of the Younger Dryas,and at 10.4.ka BP,the temperatures began to rise again;at 10.4.9.4.ka BP,it was slightly warm-wet;at 9.4.8.5 ka BP,there occurred short warm-wet oscillations;at 8.5-7.9 ka BP,it was slightly dry-cold,representing a strong temperature-lowering and drying event in the postglacial stage;at 7.8-6.3.ka BP,it was slightly warm-wet;at 6.3.4.5 ka BP,the climate tended to be cold-dry.4.5 ka BP recorded the maximum aridity since the late part of the late Pleistocene.

关键词： sedimentary environment index paleoclimatic changes late Pleistocene-Holocene(4..4.4.5 ka BP) Tai Co Tibet

Carbon and hydrogen isotopic characteristics of natural gases from the Luliang and Baoshan basins in Yunnan Province, china

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Earth Sciences 2006年第9期49卷 938-946页

作者： XU Yongchang1, LIU Wenhui2. SHEN Ping1, WANG Wanchun1, WANG Xiaofeng1, Tenger1, YAN Yaomin3.& LIU Ruobin3.1. Lanzhou Center of Oil & Gas Resources, Institute of geology and Geophsics, chinese Academy of Sciences, Lanzhou 73.000,{2. 2. Research Institute of Petroleum Exploration and Production, SINOPEC, beijing 100083.{2. 3. South Branch of Petroleum Exploration and Production Company, SINOPEC, Kuming 650000,{2. 1. Lanzhou Center of Oil & Gas Resources Institute of Geology and Geophsics Chinese Academy of Sciences Lanzhou 730000 China 2. Research Institute of Petroleum Exploration and Production SINOPEC Beijing 100083 China 3. South Branch of Petroleum Exploration and Production Company SINOPEC Kuming 650000 China

The Luliang and Baoshan basins of Yunnan Province are two small-sizedcontinental oil/gas-bearing sedimentary basins, which were developed at the bases of theCarboniferous and Devonian systems during the Late Tertiary, covering an area of 3.0} km^2.and 2.{3.m^2. respectively. Since the 1990s, there have been discovered small-sized natural gas pools inthese two basins. The natural gases are composed mainly of hydrocarbon gases, with nonhydrocarbonsaccounting for less than 2.. Of the hydrocarbon gases, methane accounts for more than 99%, and thecomponents above C_2.account for less than 0.2.. On the basis of previous studies of geologicalbackground, the composition of natural gases and their carbon isotopic composition, it has beendefined that these two gas pools are of bacterial origin. In this work we have comprehensivelymeasured the carbon and hydrogen isotopic composition of natural gases from these two basins andhave gone into the details of the mechanism of gas generation. The δ^(13.C_1 values of naturalgases from the Luliang Basin are within the range of -72.1 per thousand - -73.3.per thousand, andthe δD_(CH_{3. values, -2.0} per thousand - -2.{3.per thousand, indicating that the bacterial gasgeneration is dominated by the way of CO_2.reduction. It has been evidenced that undercontinental-facies fresh water conditions there did occur the CO_2.reduction as a process ofbacterial gas generation. The δ^(13.C_1 values of natural gases from the Baoshan Basin are withinthe range of - 62.5 per thousand - -63.5 per thousand, and the δD_(CH_{3. values, -2.2.per thousand- -2.0 per thousand. These isotopic characteristics are fallen into transitional phase of acetatefermentation and CO_2.reduction as defined by Whiticar et al. (1986). An important discovery in theLuliang Basin is the carbon isotopic composition of ethane of purely biogenetic origin, i.e., itsδ^(13.C_2.values are within the range of - 61.2.per thousand - - 66.0 per thousand. These carbonisotopic values have been r

关键词： bacterial gas, carbon and hydrogen isotope, CO2 reduction, acetate fermentation.

Estimating possible impact of human activity on the warm season temperature in beijing since the industrial era

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 2010年第16期55卷 1590-1593页

作者： QIN Li1,2.& ZHOU Xin1,2.1 Institute of geology and {3.,{2. Academy of Sciences,beijing {4.,china 2.Graduate University of {2. Academy of Sciences,beijing 10004.,china Institute of geology and geophysics Chinese Academy of Sciences Beijing China Graduate University of chinese Academy of Sciences Beijing China

Global surface temperature shows an increasing trend over the past 100 *** and natural factors have been invoked to explain this warming, but their relative contribution and the spatial variability remain *** on a 2.50-year temperature record from a stalagmite near beijing, we explore the possible impacts of human activity on the warm season temperature in beijing since the industrial era using the method of singular spectrum analysis (SSA).The results suggest that the warm season temperature in beijing under the natural forcing should have an overall decreasing trend for the past 13. years (1870 to 2.00 AD) with an amplitude of 0.4.±0.84.C, while the instrumental record and stalagmite data show an increase of 1.08°*** imply that human activity would have caused an increase in the warm season temperature of beijing for about 1.53.0.84.C compared to its natural trends, from 1870 AD to 2.00 *** results also suggest that anthropogenic forcing began to significantly influence the temperature since 1870 AD, and the effect further intensified since 1915 AD.

关键词：人类活动北京温度工业时代季节温暖估计地表气温

A circum-earth shear zone at low-latitudes and episodic large earthquakes in it and the circum-Pacific seismic zone

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2006年第9期49卷 897-903页

作者： MA Zongjin1, DU Pinren1, REN Jinwei2.& GAO Xianglin1 1. Institute of geology, china Earthquake Administration,{2., china 2. Institute of Earthquake Science, china Earthquake Administration, beijing 10003., china 1. Institute of geology China Earthquake Administration Beijing 100029 China 2. Institute of Earthquake Science China Earthquake Administration Beijing 100036 China

Because of the differential motions between the Northern and Southern Hemispheres of the Earth, there exists a motion discordant zone between them. On the surface this zone consists of 13.large faults dominant with strike-slip. We call it a global shear zone at low-latitudes (E system). By statistical analysis of temporal distribution of earthquakes Mw≥7.5 in the E system and the circum-Pacific (P system) during 1900―2.03. we find that there exist quasi-episodic and alternative activities in and between these two systems. This phenomenon is likely associated with the half-sphere oscillation in dilation and contraction and the change of the Earth’s rotation rate.

关键词： shear zone, circum-Pacific zone, great earthquake, quasi-episode.

DMTB:A comprehensive online resource of 16S rRNA genes,ecological metadata,oligonucleotides,and magnetic properties of magnetotactic bacteria

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 2011年第6期56卷 476-478页

作者： LIN Wei1,2. LI Bi1,2.& PAN YongXin1,2.1 Paleomagnetism and Geochronology Laboratory, Key Laboratory of the Earth’s Deep Interior, Institute of {3. and geophysics, {2. Academy of Sciences, beijing 10002.,{4. 2.France-china Bio-Mineralization and Nano-Structures Laboratory, Institute of {3. and geophysics, {2. Academy of Sciences, beijing 10002.,{4. Paleomagnetism and Geochronology Laboratory Key Laboratory of the Earth"s Deep Interior Institute of Geology and Geophysics Chinese Academy of Sciences France-china Bio-Mineralization and Nano-Structures Laboratory Institute of Geology and Geophysics

Magnetotactic bacteria (MTB) are of interest in microbiology, biomineralization, advanced magnetic materials, and bio-geo-sciences because of their ability to form highly ordered intracellular magnetic minerals. Great strides for MTB studies have been made in the past four decades. In this paper we complied the first internet-accessible database for MTB, Database of Magnestotactic Bacteria (DMTB). It contains information of 16S rRNA gene sequences, corresponding ecological metadata, oligonucleotides, and magnetic properties of MTB. The comprehensive information contained in DMTB will provide a very useful data resource for researchers from different disciplines. The website of DMTB is at http://***/.

关键词： rRNA基因序列趋磁细菌 16S 网上资源寡核苷酸磁学性质生态磁性材料

The freeze-thaw metallogenic model of regenerated gold placers under cold low temperature conditions

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 1999年第S2期44卷 11-13页

作者： ZHANG Baolin~1, WANG Chunhe~2. WANG Jie~1 and SONG Changchun~2.1. Institute of geology and {3., {2. Academy of Sciences, beijing 10002.,{4. 2. Changchun Institute of Geography, {2. Academy of Sciences, Changchun 13.02.,{4. Institute of geology and geophysics Chinese Academy of Sciences Beijing 100029 China Changchun Institute of Geography Chinese Academy of Sciences Changchun 130021 China

LOCATED in the mined-out areas of primary gold placers, the regenerated gold placers in permafrost zonesare a kind of special low temperature deposit formed under modem cold climate conditions. Although theregeneration phenomenon was first discovered in South America, the scale and periodicity of the regeneration are more evident in permafrost environment of Northern Hemisphere.

关键词： regeneration gold placer freeze-thaw model.

Age of Yingfeng rapakivi granite pluton on the north flank of Qaidam and its geological significance

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2004年第4期47卷 357-365页

作者： XIAO Qinghui1,2. LU Xinxiang1,3. WANG Fei4. SUN Yangui5, WEI Xiangdong3.& XING Zuoyun6 1. Division of Granite geology,{2. Geological Survey, Yichang 4.3.03.{2. 2. Information Center of Ministry of Land and Resources, beijing 100812.{2. 3. Geological Survey of Henan Province and Institute of Geological Research of Henan Province, Zhengzhou 4.0053.{2. 4. Geological Institute,{2. Seismological Bureau, beijing 10002.,{2. 5. Geological Survey Institute of Qinghai Province, Xining 81003.0}{2. 6.{2. University of Geosciences, Wuhan 4.0074.{2. Division of Granite geology China Geological Survey Yichang 443003 China Information Center of Ministry of Land and Resources Beijing 100812 China Geological Survey of Henan Province and Institute of Geological Research of Henan Province Zhengzhou 450053 China Geological Institute China Seismological Bureau Beijing 100029 China Geological Survey Institute of Qinghai Province Xining 810032 China china University of Geosciences Wuhan 430074 China

The Yingfeng rapakivi granite on the north flank of Qaidam is a newly discovered Proterozoic rapakivi pluton in china, which was found after the discovery of Shachang rapakivi in Miyun County, beijing and Kuandian rapakivi in Jilin Province. Yingfeng rapakivi pluton is ex-posed on the north side of the suture belt between Qinling-Kunlun orogenic belt and North china plate. U-Pb zircon isotopic dating and Ar-Ar isotopic dating of both hornblende and K-feldspar from the Yingfeng rapakivi granite have been conducted. The results show that the age of (1776±3.)Ma at the upper intercept in Concorde diagram represents the age of formation of the plu-ton, whereas the age of (5{3. {3.1) Ma at the lower intercept and Ar-Ar mineral dating of horn-blende and K-feldspar correspond to the age of a later event affecting the pluton, suggesting that Yingfeng pluton has ever been affected by strong regional Caledonian-Hercynian tectonic movement after its formation. The discovery of middle Proterozoic Yingfeng rapakivi granite pro-vides a petrologic evidence for the timing of cratonization of both the continental crust basement in western china and the basement of the North china plate and for a rifting event taking place in the mid-Proterozoic, suggesting that an amalgamation of ancient china continents had ever happened during the L liang Movement?between the early Proterozoic and the mid-Proterozoic.

关键词： rapakivi, U-Pb dating, Ar-Ar dating, Kunlun-Qinling orogenic belt.

The crystal structure of (Fe_(4.Cr_(4.Ni)_(9)C_(4.

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2005年第3期48卷 338-345页

作者： SHI Nicheng1, MA Zhesheng1, XIONG Ming1, DAI Mingquan1, BAI Wenji2. FANG Qingsong2. YAN Binggang2.& YANG Jingsui2.1. X-ray Diffraction Laboratory, china University of Geosciences, beijing 100083. china 2. Institute of geology, {4. Academy of Geological Sciences, beijing 10003., china 1. X-ray Diffraction Laboratory China University of Geosciences 100083 Beijing China 2. Institute of geology Chinese Academy of Geological Sciences 100037 Beijing China

(Fe4.r4.i)9C4.is a metal carbide mineral formed by combination of Fe, Cr and Ni with C. It occurs in a chromite deposit in the Luobusha ophiolite, Tibet. Based on the determina- tion of its crystal structure, the empirical formula is (Fe4.12.r3.84.i0.96)8.92.3.70 and the simplified formula is (Fe4.r4.i)4.9. The mineral is hexagonal with a = 1.3.3.2.2. nm, c = 0.4.690(9) nm, space group P63.m c, Z=6 and the calculated specific gravity Dx = 7.089 g/cm3. Fe, Cr and Ni occupy different crystallographic sites and their coordination numbers are approximately 12. forming an alternate stacking sequence of flat and puckered layers along the c axis. Some me- tallic atoms have a defect structure. The interatomic distances of Fe, Cr and Ni are 0.2.2.— 0.2.66 nm, and the distances between Fe, Cr, Ni and C are 0.1893.0.2.69 nm. The coordina- tion number of carbon is 6. It occurs in interstices of the metallic atoms Fe, Cr and Ni to form trigonal-prismatically coordinated polyhedra. These coordination polyhedra are linked with each other via shared corners or shared edges into a new type of metal carbide structure.

关键词： Luobusha of Tibet, metal carbide, crystal structure.

Genesis of excess argon in phengite and significance of ^(4.)Ar-^(3.)Ar age spectra for omphacite:A case study on UHP eclogite of South Dabie Terrain,china

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 2000年第15期45卷 1345-1351页

作者： WANG Songshan, GE Ningjie, SANG Haiqing & QIU Ji1. Institute of geology and geophysics, {2. Academy of Sciences,{3.,{4. 2. Department of Earth and Space Science, University of Science and Technology of{4., Hefei 2.002.,{4. Correspondence should be addressed to Wang Songshan Institute of geology and geophysics Chinese Academy of Sciences Beijing China Department of Earth and Space Science University of Science and Technology of China Hefei China

The Ar-Ar dating of phengite and omphacite in ultrahigh-pressure (UHP) eclogite of Bixiling and Hengchong in the South Dabie Terrain shows that the content range of excess argon is as high as (0.4.1.3.×10 8 mol· g 1. The genesis of the excess argon is discussed. The Ar-Ar age spectra of omphacite could not support the opinion that the UHP metamorphism occurred in Caledon epoch and pre-Caledon epoch.

关键词： South Dabie Terrain ultrahigh-pressure metamorphics phengite omphacite excess argon.