检索结果-南通市图书馆

Geological Features of Triassic Alkaline and Subalkaline Igneous Complexes in the Yan-Liao Area

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 1992年第4期66卷 339-355页

作者： Mou Baolei Yan Guohan department of geology, Peking university, Beijing Fei Zhenbi department of geology Peking University Beijing

A number of Triassic (245-195 Ma) alkaline or subalkaline igneous complexes were discovered in theYan-liao area in the northern part of the North China platform. These complexes are all poor in SiO_2; most ofthem are rich in Fe, Mg, K and P and such incompatible elements as Rb, Ba, U and Sr and REE; theinitial ^(87)Sr / ^(86)Sr ratios range from 0.7055 to 0.7057. They might have originated in the altered upper *** that basis coupled with the distribution of the Triassic System and the tectonic deformation, it is suggestedthat there should have existed a tectono-magmatic belt in the area in Triassic time, which is an important mani-festation of the Indosinian movement in the area.

关键词： Yan-Liao area alkaline or subalkaline complexes geochemistry

Distributions of fatty acids in a stalagmite related to paleoclimate change at Qingjiang in Hubei,southern China

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2005年第9期48卷 1463-1469页

作者： XIE Shucheng1,HUANG Junhua1,WANG Hongmei2,YI Yi1,HU Chaoyong1, caI Yanjun3.& CHENG Hai4 1. Faculty of Earth Science,China university of Geosciences,Wuhan 43.074,China 2. School of Environmental Studies,China university of Geosciences,Wuhan 43.074,China 3. SKLLQG,Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710075,China 4. department of {3. and geophysics,university of Minnesota,MN55455,usa Faculty of Earth Science China University of Geosciences Wuhan China School of Environmental Studies China University of Geosciences Wuhan China SKLLQG Institute of Earth Environment Chinese Academy of Sciences Xi’an China department of geology and geophysics University of Minnesota USA

Fatty acids extracted from a subtropical stalagmite at Qingjiang in Southern China’s Hubei Province were analysed using gas chromatography-mass spectrometry. These n-alkanoic acids range from C14 to C26 in carbon number, maximizing at C16, with a second dominance at C22. In contrast to the stalagmite analysed, the overlying soils are characterized by the dominance of heavy-molecular-weight homologues (>C20). The n-fatty acids in the stalagmite were proposed to be contributed by both the soil ecosystems and the microbes harboring in the percolating water and the cave. The ratios of unsaturated to saturated n-fatty acids (C16:1i/C16:0, C18:1/C18:0) appear to show trends comparable with the oxygen isotope records of the stalagmite carbonate, with enhanced values associated with the cold episode such as Heinrich event 1. This paleoclimate-dependent record of the n-fatty acids might reflect microbial changes in physiology and activity in response to the temperature. This record shows somewhat difference from the previous paleoclimate signal extracted from n-alkanols and n-alkan-2-ones of the same stalagmite. The acid record fails to document the well-known Younger Dryas event which was effectively shown by the latter two biomarkers derived from soil ecosystems. This discrepancy might result from the changing biogeochemical impact on different lipid fractions as well as the varied organism populations in different ecosystems.

关键词： biomarker, ecosystem, microbe, speleothem, paleoclimate, Quaternary.

Comprehensive evaluation of mechanism of "chimney effect" using principles of magnetism, geochemistry and mineralogy

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第9期43卷 743-748页

作者： LIU Qingsheng 1, CHENG Tongjin 2 and LIU Shugen 3.1. department of Applied geophysics, China university of Geosciences, Wuhan 43.074, China 2. Center of Petroleum Geochemistry, China National Star Petroleum Corporation, Hefei 23.022, China 3. The St department of Applied geophysics China University of Geosciences Wuhan China Center of Petroleum Geochemistry China National Star Petroleum Corporation Hefei China The State Key Laboratory of Oil/Gas Reservoir geology and Exploitation of China Chengdu Institute of Technology Chengdu China

Study of forming mechanism of "chimney-effect" (CE) has important significance for basic theory and applications of non-seismic geophysical and geochemical methods locating oil/gas reservoirs. The theoretical basis of comprehensive evaluation of mechanism of CE using principles of magnetism, geochemistry and mineralogy has been reviewed, with the problems to be solved: (ⅰ) study for the relationship between process of oil/gas migration and geochemical field; (ⅱ) analysis of genesis of magnetic, geochemical and mineralogical anomaly; (ⅲ) interpretation of surface soil magnetism and geochemical anomaly combined with seismic data.

关键词： chimney effect (CE) hydrocarbon microseepage oil/gas accumulation.

Interactions between hotspots and the Southwest Indian Ridge during the last 90 Ma:Implications on the formation of oceanic plateaus and intra-plate seamounts

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2011年第8期54卷 1177-1188页

作者： ZHANG Tao 1,2,3.4,LIN Jian 5 & GAO JinYao 3.4 1 Institute of Geodesy and geophysics,Chinese Academy of Sciences,Wuhan 43.077,China 2 Graduate university of Chinese Academy of Sciences,Beijing 100049,China 3.The Second Institute of Oceanography,State Oceanic Administrator,Hangzhou 3.0012,China 4 Key Laboratory of Submarine Geosciences,State Oceanic Administrator,Hangzhou 3.0012,China 5 department of {3. and geophysics,Woods Hole Oceanographic Institution,Woods Hole,MA 02543.usa Institute of Geodesy and geophysics Chinese Academy of Sciences Wuhan China Graduate university of Chinese Academy of Sciences Beijing China The Second Institute of Oceanography State Oceanic Administrator Hangzhou China Key Laboratory of Submarine Geosciences State Oceanic Administrator Hangzhou China

This study investigates the relationship between the hotspot-ridge interaction and the formation of oceanic plateaus and seamounts in the Southwest Indian *** first calculated the relative distance between the Southwest Indian Ridge (SWIR) and relevant hotspots on the basis of models of plate reconstruction,and then calculated the corresponding excess magmatic anomalies of the hotspots on the basis of residual bathymetry and Airy *** results reveal that the activities of the Marion hotspot can be divided into three main phases:interaction with the paleo-Rodrigues triple junction (73.6-68.5 Ma),interaction with the SWIR (68.5-42.7 Ma),and intra-plate volcanism (42.7-0 Ma).These three phases correspond to the formation of the eastern,central,and western parts of the Del cano Rise,*** magnitude and apparent periodicity of the magmatic volume flux of the Marion hotspot appear to be dominated by the hotspot-ridge *** periodicity of the Marion hotspot is about 25 Ma,which is much longer than that of the Hawaii and Iceland hotspots (about 15 Ma).

关键词： Southwest Indian Ocean hotspot-ridge interaction magmatic volume flux oceanic plateaus seamounts

The Experimental Results of Pb and Zn Partitioning between Fluid and Melt, and Their Application to the Research on Metallogeny

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 1989年第2期63卷 189-196页

作者： Peng Shenglin department of geology, Central-South university of Technology, Changsha, Hunan Province department of geology Central-South University of Technology Changsha Hunan Province

Three logarithmic linear equations between D_(Me)^(V/L) and [m_(NaCl)], and the relationship of D_(Me)^(V/L) versus F/Cl or K/Na mole ratios have been established by the experiments of the partitioning of Pb and Zn between granitic silicate melt and aqueous fluid. These results have been used to quantitatively study some essential problems, such as the possibility and degree of Pb-Zn mineralization in the system of granitic magma and hydrothermal fluid, and the influence of the relative contents of alkali and volatiles on the Pb-Zn mineralization in the same system. Some new points have been put forward in this paper.

关键词： and Their Application to the Research on Metallogeny The Experimental Results of Pb and Zn Partitioning between Fluid and Melt Zn Pb

PGE patterns of ores of Dajing Cu-polymetallic deposit in Linxi County, Inner Mongolia:Indicator to source of metallogenic elements

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2002年第13期47卷 1119-1124页

作者： CHU Xuelei, SUN Min & ZHOU MeifuInstitute of geology and geophysics, Chinese Academy of Sciences, Beijing 100029, China Key Laboratory of Mineral Resources, Institute of geology and geophysics, Chinese Academy of Sciences, Beijing 100101, China department Institute of geology and geophysics Chinese Academy of Sciences Beijing China Key Laboratory of Mineral Resources Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China department of Earth Sciences The University of Hong Kong Hong Kong China

By comparing PGE patterns of sulfide ores with that of basic-ultrabasic dikes occurring in the Dajing Cu-polymetallic deposit, we discover that there are similar positive slopes between the basic-ultrabasic dikes and the black ores composed mainly of sphalerite and galena, reflecting affinity of their source. The PGE patterns of the yellow ores composed basically of chalcopyrite, arsenopyrite and pyrite are actually different. One is close to the pattern of the mantle 1herzolite, and others resemble the pattern of the basic rocks. However, the concentrations of Ru are higher in the yellow ores, reflecting that sulfur attains or approaches saturation in their parent magma. The PGE characteristics of ores and dikes show that the magmas derived from the deep of crust and the metallogenic elements were supplied mainly by growth material of the crust. In addition, the mantle-derived magma also offered some elements.

关键词： Da Hinggan area polymetallic deposit PGE pattern hypomagma.

Hydrogen isotopic characteristics and their genetic relationships for individual n-alkanes in plants and sediments from Zoigê marsh sedimentary environment

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2010年第9期53卷 1329-1334页

作者： DUAN Yi1, ZHENG ChaoYang2 & WU BaoXiang1 1 Key Laboratory of Petroleum Resources Research, Institute of geology and geophysics, Chinese Academy of Sciences, Lanzhou 73.000, China 2 department of geology, Northwest university, Xi’an 710069, China Key Laboratory of Petroleum Resources Research Institute of Geology and Geophysics Chinese Academy of Sciences Lanzhou China department of geology Northwest University Xi’an China

To understand internal relations of their hydrogen isotopic compositions in typical marsh environment, we, using GC-IRMS analytical technique, measured the hydrogen isotopes of individual n-alkanes in the herbaceous plant, woody plant leaf, and sediments from Zoigê marsh in China. The results show significant differences in the hydrogen isotopic compositions of n-alkanes among the different kinds of plants and the different species in the same kind. δD values of n-alkanes in the herbaceous plants (from -254‰ to -184‰) are lighter than those in woody plant leaf ( from -195‰ to -142‰ ), and the hydrogen isotopic compositions of n-alkanes in K. tibetica P. are lighter than P. pratensis L. The mean δD values of n-alkanes in the sediments from Zoigê marsh reflect that they were derived from herbaceous plants, which is consistent with the peat samples being composed mainly of herbaceous plant remnants. The significant differences in hydrogen isotopic compositions of n-alkanes among the sedimentary samples are caused possibly by environment factors and the difference in input quantity of different herbaceous plants. A certain negative correlation exists between the δ13. and δD values of n-alkanes in the samples, and plant types can be distinguished using the cross plot of δD vs. δ13. values of n-alkanes in the plants. These data and recognitions provide scientific basis for hydrogen isotopic applied research of individual n-alkanes.

关键词： marsh environment plants sediments individual lipids hydrogen isotopes genetic relationship

Petrographic Features and Sedimentary Environments of the Middle-Upper Ordovician at Shetai Town of Urad Front Banner, Inner Mongolia

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 1991年第4期65卷 401-416,459页

作者： Zhang Xiulian Wang Yinghua Pan Rongsheng department of geology,Peking university Liu Linqun department of geology Peking University

Most of the hinterland of the North China platform is devoid of Late Ordovician strata. The BaiyanhuaMountain section at Shetai Town is a standard section of the Upper Ordovician newly established in recentyears at the northernmost margin of the platform. This establishment directly involved the determination of thenorth boundary of the platform and the understanding of its evolutionary Listory. The area is quite differentfrom the binterland of the platform in Middle Ordovician rock types and sedimentary environments, with theformer characterized by frequent slope deposits and the latter consisting almost entirely of platform deposits.The present paper focuses on the petrographic features and sedimentary ervironments of the Middle-UpperOrdovician strata in the area, providing further theoretical support to the establishment of the section and fil-ling the gap in this respect.

关键词： Petrographic Features and Sedimentary Environments of the Middle-Upper Ordovician at Shetai Town of Urad Front Banner

Metallogenic characteristics of epithermal gold deposits in Tianshan, Xinjiang, China

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 138-139页

作者： FENG Jianzhong~1, FU Shuixing~2, WU Dewen~3.and YANG Zian~3.1. department of geology, Peking university, Beijing 100871, China 2. Beijing Institute of geology for Mineral Resources, Beijing 100012, China 3. Center of Remote Sensing for geology, CNNC, Beijing 101601, China department of geology Peking University Beijing 100871 China Beijing Institute of geology for Mineral Resources Beijing 100012 China Center of Remote Sensing for geology CNNC Beijing 101601 China

TIANSHAN in southern Xinjiang belongs to the Paleozoic island arc system in which volcanic rocks are extensively distributed. A series of epithermal gold deposits such as the Axi, Xitan, Cuiling andShuangfengshan gold deposits have been discovered. 1 Geological settings of epithermal gold deposits in Tianshan, southern Xinjiang Tianshan in southern Xinjiang belongs to the Paleozoic island arc system. To its north is the Kazakhstan plate, and to its north is the Tarim plate. From west to east, the tectonic units are characterizedby Yili island arc, southern Tianshan arc-basin, Jiaoluotage island arc and Xingxingxia island arc. TheEW-trending Tianshan ore belt is controlled by Kanggurtag geosuture. In its west part, it is controlled byShenglidaban geosuture. The linear structure is NNW-trending; from north to south, the faults

关键词： metallogenic characteristics gold deposits Tianshan Xinjiang.