检索结果-南通市图书馆

Geochemical Mapping:With Special Emphasis on Analytical Requirements

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2008年第2期82卷 451-462页

作者： XIE Xuejing CHENG Hangxin LIU Dawen Research Center of Applied Geochemistry Institute of Geophysical and Geochemical Exploration Chinese Academy of Geological Sciences Langfang Hebei 065000 Development and Research Center China Geological Survey Chinese Academy of Geological Sciences Langfang Hebei 065000

More than 40 national and regional geochemical mapping projects in the world carried out from 1973 to 1988 do not conform to common standards. In particular they have many analytical deficiencies. In the period 1988 to 1992, the International Geochemical Mapping project （Project 259 of UNESCO＇s IGCP Program） prepared recommendations designed to standardize geochemical mapping methods. The analytical requirements are an essential component of the overall recommendations. They included the following： 71 elements should be analyzed in future mapping projects; the detection limits of trace and ultratrace elements must be lower than the corresponding crustal abundances; and the Chinese GSD and Canadian STSD standard sample series should be used for the correlation of global data. A proposal was also made to collect 5000 composite samples, at very low sampling densities to cover the whole Earth＇s land surface. In 1997 an IUGS Working Group on Global Geochemical Baselines was formed to continue the work which began with IGCP 259. From 1997 up to now, new progress has been made especially in China and FOREGS countries under the aegis of this working group, including the study of suitable sampling media, development of a multi-element analytical system, new proficiency test for selection of competent laboratories and role of wide-spaced mapping in mineral exploration. One of the major problems awaiting solution has been the inability of many laboratories to meet the IGCP recommendations to generate high quality geochemical maps. Fortunately several laboratories in China and Europe have demonstrated an ability to meet the requirements and they will be well placed to render technical assistance to other countries.

关键词： geochemical mapping geoanalysis analytical requirement extremely low density sampling

Geomorphic signatures of active tectonics in Subansiri River Basin, eastern Himalayas

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2020年第6期17卷 1523-1540页

作者： Diganta KUMAR Bhagawat Pran DUARAH Department of geological Sciences Gauhati UniversityGuwahatiAssam-781014India

The Subansiri,a major tributary of the Brahmaputra with its catchment area(35763 km^2)spreading almost entirely in the Eastern Himalayas across almost all the major and local tectonic features in the area witnesses large numbers of seismic *** tectonic indices like relief and slope,drainage pattern,longitudinal profile,valley profile,hypsometry,valley asymmetry factors and transverse topographic symmetry index,stream length gradient,valley floor-height ratio extracted from SRTM 3 arcsecond data prove that the evolving basin morphology has substantial contribution from the Himalayan *** data are incorporated in the study to establish the potentially active tectonic elements in the catchment *** study shows that the western part of the Subansiri River Basin is profoundly tilted towards north in the upper catchment and towards east in the lower and middle part of the *** predominant tectonic movements in the western part of the basin caused the tilting of the basin towards north in the upstream and towards east in the middle and lower parts.

关键词： Eastern Himalayas Active tectonics Subansiri Geomorphometry SRTM DEM Seismicity

Natural gas origins of large and medium-scale gas fields in China sedimentary basins

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2008年第S1期51卷 1-13页

作者： ZHANG ShuiChang &ZHU GuangYou Research Center of Research institutes of PetroChina Exploration and Development,Beijing 100083,China Research Center of Research institutes of PetroChina Exploration and Development Beijing China

China sedimentary basins present abundant natural gas resource thanks to its unique geological *** highly-matured hydrocarbon source rocks,widespread coal-measure strata and low temperature Quaternary saline strata,etc.,indicate the wide foreground of China natural gas resources. Up to now,most of the petroliferous basins have been discovered to have wholesale natural gas accumulation from Precambrian,Paleozoic,Mesozoic to Cenozoic in the east,the central,the west and the coast of *** large and medium-scale gas reservoirs are mainly composed of hydrocarbon gas with big dry coefficient,tiny non-hydrocarbon,wide carbon isotope distribution and varying origin types,the hydrocarbon gas includes coal-formed gas,oil-formed gas,biogenic gas and inorganic gas, ***-formed gas is the main type of China natural gas resources,in particular several explored large-scale gas fields(>100 billion cubic meter)of Kela 2,Sulige and Daniudi,etc.,they all belong to coal-formed gas fields or the gas fields consisting mostly of coal-formed ***-formed gas is also abundant in China marine basins,for example marine natural gas of Sichuan Basin generated from crude oil cracking *** and secondary biogenic gas fields were discovered respectively in the Qaidam Basin and Western Slope of Songliao *** addition,inorganic gases are mainly distributed in the eastern China,in particular the Songliao Basin with abundant carbon dioxide accumulation,indicating that the eastern China present large exploration potential of inorganic gas.

关键词： natural gas origin sedimentary basin large and medium-scale gas field

Non-matrix-matched analysis of U-Th-Pb geochronology of bastn?site by laser ablation inductively coupled plasma mass spectrometry

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2021年第4期64卷 667-676页

作者： Tao LUO He ZHAO Wen ZHANG Jingliang GUO Keqing ZONG Yongsheng LIU Junfeng ZHANG Zhaochu HU State Key Laboratory of geological Processes and Mineral Resources China University of GeosciencesWuhan 430074China

Bastn?site is widespread in alkali granite, carbonatite and REE ore deposits. The U-Th-Pb ages of bastn?site can constrain the mineralization age. Currently, the lack of suitable in situ analysis reference material is the major obstacle of bastn?site U-Th-Pb geochronology. In this study, the matrix effects of U-Pb and Th-Pb age determination in bastn?site using glass NIST 610 as the external calibration reference were evaluated with the 193-nm excimer LA-ICP-MS analysis in normal and additional gases laser ablation modes. The obtained U-Th-Pb ages of bastn?site were approximately 7–11% lower than their reference values in the normal analytical mode(without additional gas). Fortunately, the determined systematic age biases in UTh-Pb dating were significantly reduced(less than 1–2%) with the addition of water vapor within the ablation chamber. This reduction may be attributed to the observed significant suppression of206 Pb/238 U and208 Pb/232 Th downhole fractionation in both NIST 610 glass and bastn?site by introducing a small quantity of water vapor in the ablation chamber. In addition, the obtained206 Pb/238 U and208 Pb/232 Th ages of bastn?site K-9, LZ1384, and MAD809 showed great consistency with their corresponding recommended values. The obtained results show that accurate and precise U-Th-Pb ages of bastn?site can be simultaneously obtained by using glass NIST 610 as the primary calibration standard in 193-nm LA-ICP-MS with the water vapor-assisted method. This simple and effective water vapor-assisted non-matrix-matched laser ablation method helps to promote the geological application of bastn?site U-Th-Pb geochronology.

关键词： LA-ICP-MS U-Th-Pb ages Non-matrix-matched method Bastn?site

Separation and Precise Measurement of Lithium Isotopes in Three Reference Materials Using Multi Collector-Inductively Coupled Plasma Mass Spectrometry

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2012年第5期86卷 1297-1305页

作者： TIAN Shihong HOU Zengqian SU Aina HOU Kejun HU Wenjie LI Zhenzhen ZHAO Yue GAO Yanguang LI Yanhe YANG Dan YANG Zhusen School of Earth Science and Mineral Resources China University of GeosciencesBeijing 100083China Key Laboratory of Metallogeny and Mineral Assessment Ministry of Land and ResourcesInstitute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China Institute of Hydrogeology and Environmental Geology Chinese Academy of Geological SciencesShij'iazhuangHebei 050061China Jiangxi Provincial Institute of geological Survey Nanchang 330030China Kunming University of Science and Technology KunmingYunnan 650093China China geological Survey Beijing 100037China

Lithium separation technique for three reference materials has been established together with precise determination of lithium isotope using a Neptune multi collector-inductively coupled plasma mass spectrometry （MC-ICP-MS）. The solutions of lithium element standard reference materials, potassium, calcium, sodium, magnesium and iron single element, were used to evaluate analytical methods applied. Three separate stages of ion-exchange chromatography were carried out using organic cation-exchange resin （AG 50W-X8）. Lithium was enriched for the three stages using different eluants, which are 2.8 M HCl, 0.15 M HCl and 0.5 M HCl in 30% ethanol, respectively. The columns for the first and second stages are made of polypropylene, and those for the third stage are made of quartz. Total reagent volume for the entire chemical process was 35 mL for three reference materials. The recovery yielded for the three stages is 98.9-101.2% with an average of 100.0%, 97.6-101.9% with an average of 99.9%, and 99.8-103.3% with an average of 100.6%, respectively. The precision of this technique is conservatively estimated to be ±0.72-1.04‰ （2σ population）, which is similar to the precision obtained by different authors in different laboratories with MC-ICP-MS. The δ7 Li values （ 7 Li/ 6 Li relative to the IRMM-016 standard） determined for andesite （AGV-2） and basalt （BHVO-2） are 5.68‰ （n=18）, 4.33‰ （n=18）, respectively. The δ7 Li value （ 7Li/6Li relative to the L-SVEC standard） determined for IRMM-016 is -0.01‰ （n=15）. All these analytical results are in good agreement with those previously reported. In addition, the results for the same kinds of samples analyzed at the MLR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of geological Sciences, are consistent with those obtained at the Plasma Laboratory, University of Maryland, within analytical uncertainty. According to these experiment results, it is concluded that this proposed proc

关键词： lithium isotopes standard solution AGV-2 BHVO-2 IRMM-016 MC-ICP-MS

Zircon SHRIMP U-Pb Dating and Geochemical Characteristics of Late Variscan Granites of the Daitongshan Copper Deposit and Lamahanshan Polymetallic-Silver Deposit, Southern Daxing'anling, China

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2013年第5期24卷 772-795页

作者：周振华李泊洋王挨顺武新丽欧阳荷根冯佳睿 MRL Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological Sciences No. 10 Institute of geological Exploration Inner Mongolia Bureau of Geology & Mineral Resources geological Survey Institute of Inner Mongolia School of Earth Science and Mineral Resources China University of Geosciences Research Institute of Petroleum Exploration and Development PetroChina

Daxing＇anling （大兴安岭） area is one of the regions that Phanerozoic granites are extremely developed in NW China. At present, the Hercynian granitoid research lags behind the Mesozoic granitoid research. In this article, we have taken systematic petrochemistry and geochronology researches on the Hercynian granitoids in Daitongshan （代铜山） copper deposit and Lamahanshan （喇嘛罕山） silver poly- metallic deposit, which were located at southern section of Daxing＇anling metallogenic belt. Zircon SHRIMP U-Pb dating results show that, the granite aplites in Daitongshan and the gneissic granites inLamahanshan were formed at （265±5）-（268±9） Ma and （252±2）-（252.6±3.4） Ma, respectively, which were both the products of late Herynian tectonic-magmatic events. Samples from Lama- hanshan are characterized by high SiO2 （69.72 wt.%-74.65 wt.%）, high potassium （3.53 wt.%-4.55 wt.%） and low P205 （0.03 wt.%0.12 wt.%）, aluminum saturation index （A/CNK） range from 0.95 to 0.98, Rb, Nd and K are en- riched, whereas the elements such as Nb, Ta, P and Ti are depleted, which belong to I-type grani- toids. Characteristics of samples from Daitong- shan are similar to H-type granitoids. The magmasource may be mostly originated from the lithospheric mantle component which were transformated or affected by the subduction components, and its formation may be closely related with the subduction and orogenesis of the Paleo-Asian Ocean.

关键词： SHRIMP U-Pb dating geochemistry Variscan Daitongshan copper deposit Lamahan-shan silver polymetallic deposit Daxing'anling.

Origins of the supercontinent cycle

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2013年第4期4卷 439-448页

作者： R.Damian Nance J.Brendan Murphy Department of Geological Sciences.316 Clippinger Laboratories.Ohio University.Athens.OH 45701.USA Department of Earth Sciences st.Francis Xavier UniversityAntigonishNova Scotia B2G 2W5.Canada

The supercontinent cycle, by which Earth history is seen as having been punctuated by the episodic assembly and breakup of supercontinents, has influenced the rock record more than any other geologic phenomena, and its recognition is arguably the most important advance in Earth Science since plate tectonics. It documents fundamental aspects of the planet＇s interior dynamics and has charted the course of Earth＇s tectonic, climatic and biogeochemical evolution for billions of years. But while the widespread realization of the importance of supercontinents in Earth history is a relatively recent development, the supercontinent cycle was first proposed thirty years ago and episodicity in tectonic processes was recognized long before plate tectonics provided a potential explanation for its occurrence. With interest in the supercontinent cycle gaining momentum and the literature expanding rapidly, it is instructive to recall the historical context from which the concept developed. Here we examine the supercontinent cycle from this perspective by tracing its development from the early recognition of long-term epi- sodicity in tectonic processes, through the identification of tectonic cycles following the advent of plate tectonics, to the first realization that these phenomena were the manifestation of episodic superconti- nent assembly and breakup.

关键词： Supercontinent cyclePlate tectonicsTectonic episodicitySecular trends

Balanced Cross-Section and Crustal Shortening Analysis in the Tanggula-Tuotuohe Area,Northern Tibet

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2011年第1期22卷 1-10页

作者：李亚林王成善马超 Ganqing Xu Xixi Zhao State Key Laboratory of geological Processes and Mineral Resources School of the Earth Sciences and Resources Research Center for Tibetan Plateau Geology China University of Geosciences Beijing 100083 China Department of Earth and Ocean Science University of Waikato Hamilton New Zealand institutes of Geophysics and Planetary Physics University of California Santa Cruz CA95064 USA

The Tanggula （唐古拉） thrust system and the Tuotuohe （沱沱河） foreland basin, which represent major Cenozoic tectonic units of the central Tibetan plateau, have been recently studied. Field investigation, analyses of deformation and construction of two restored balanced structural sections suggest 75-100 km （51%-64%） of N-S shortening in the Tanggula thrust system and 55-114 km （42%-47%） of N-S shortening in the Tuotuohe basin. The shortening ratios indicate that the Tanggula- Tuotuohe area has undergone intensive deformation and crustal shortening during the Early Tertiary, resulting not only in crustal thickening, but also in large scale volcanism and in rapid uplift of the Tanggula Mountains.

关键词： Tibetan plateau Tanggula Mountains balanced cross-section crustal shortening uplift.

Organic compositions of lacustrine source rocks in Jiyang super-depression and its implication to petroleum geology

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2006年第5期51卷 573-584页

作者： ZHANG Linye SONG Yitao WANG Guangli HUANG Difan Institute of geological Sciences Shengli Oilfield Co. Ltd. Dongying 257015 China Institute of Petroleum Exploration and Development CNPC Beijing 100083 China Key laboratories for Petroleum Formation Mechanisms Chinese Ministry of Education Petroleum University of China Beijing 102249 China

The compositions of organic matter in four immature source rocks from Tertiary strata of Jiyang super-depression, the most typical continental rift subsidence basin in East China, have been stud- ied by different extracting methods with CHCl3, MAC and CS2/NMP, respectively. The results suggest that there are great differences among the chemical compositions of organic matter in the source rocks derived from different depositional environments. About 79% of all the organic matter exists by non- covalent bond in the Es4 source rocks which were deposited under the saline lacustrine, indicating that its organic matter is not the real kerogen, but mainly composed of soluble organic matter which is easy to generate hydrocarbon at lower temperature. This is why the immature oils were derived from Es4 source rocks in Dongying depression. In contrast, around 60% of organic matter exists by covalent bond in Es3 source rocks which were deposited under the deep brackish-fresh lacustrine, showing that Es3 source rocks are mainly composed of kerogen producing mature hydrocarbon at higher temperature. The thermal simulation experiments, upon the remaining solid source rocks which were sequentially extracted by the three solvents, have been carried out. The chloroform extracts from the simulation product have been compared with the other three solvent extracts gained at room temperature. It is obvious that re-markable odd/even predominance (OEP) is mainly the characteristic of soluble organic matter; phytane mostly exists in the soluble organic matter by means of non-covalent bonds and characteristics of soluble organic matter are similar to these in immature oils produced in Jiyang super-depression.

关键词：有机成分 CS2/NMP混合溶剂非共价键未成熟生油岩可溶有机质石油地质学不成熟石油