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1.
煤型气烃类组分的稳定碳、氢同位素组成研究   总被引:18,自引:3,他引:18  
我国主要含油气盆地中的煤型气和油型气烃类气体的稳定碳、氢同位素组成的对比研究表明:煤型气甲烷的碳同位素组成在未成熟到低成熟阶段(R0<0.7%)与油型气无明显差别。从低成熟开始,煤型气甲烷随热演化程度的增高相对油型气逐渐富集重碳同位素。在热演化程度达到1.0左右时,二者δ13C1的差别最大(达7‰左右)。之后随热演化程度的增加,二者δ13C1的差值逐渐减小,当热演化程度达到过成熟阶段之后,二者又基本相近。煤型气和油型气重烃的碳同位素组成,主要受气短岩母质碳同位素组成的控制。重烃的碳同位素组成是鉴别煤型气和油型气的较有效的指标,通常煤型气的δ13C2>-28‰,而油型气的δ13C2<-28‰。热演化程度对煤型气重烃的碳同位素组成影响不够明显,而对油型气重烃碳同位素组成有一定的影响。煤型气(甲烷及重烃)的氢同位素组成主要与源岩沉积时的水介质有关,由陆相淡水环境沉积的源岩形成的煤型气相对富集氢同位素气。煤型气从甲烷到了烷随着碳数的增加,氢同位素组成依次增重,即δD1<δD2<δD3<δD4.  相似文献   

2.
天然气碳同位素部分反序与乙烷碳同位素特征的模拟研究   总被引:4,自引:1,他引:3  
郑建京  吉利明 《沉积学报》1999,17(12):811-814
通过煤系源岩热模拟烃类气地球化学研究,结合源岩自然演化形成天色气的研究,认为煤原岩在热演经进行中,随化程度增高δ^13C1值从轻变重,δ^13C2变化较小,在低演化阶段一般为-28‰±(Ro=0.45%~0.56%),当源岩进入生烃门限阶段δ^13C2值一般为-26‰~23‰左右。且随热演化程度增高进一步变重,但一般不大于-20‰。烃类气碳同位素系列4 部分反序现象,不仅仅是不同成因天然气混源特征  相似文献   

3.
塔里木盆地前陆区和台盆区天然气的地球化学特征及成因   总被引:4,自引:1,他引:3  
通过对塔里木盆地天然气碳氢同位素分析,主要存在两种类型天然气,即油型气与煤型气。油型气烷烃气碳同位素组成较轻(δ13C2<-28‰,δ13C3<-25‰),氢同位素组成偏重,成烃母质主要为海相沉积环境形成的寒武系—下奥陶统或中下奥陶统烃源岩,分布区域主要为台盆区;而煤型气烷烃气碳同位素组成较重(δ13C2>-28‰,δ13C3>-25‰),氢同位素组成偏轻,成烃母质主要为陆相沉积环境形成的三叠系—侏罗系烃源岩,分布区域主要为前陆区。在塔里木盆地,烷烃气同位素组成局部倒转主要与烃源岩热演化程度差异有关;同时,在局部地区硫酸盐热还原(TSR)也可引起碳同位素组成的局部倒转。塔里木盆地天然气中3He/4He值偏高可能与残留在岩石中的少量深部气体混入气藏有关。  相似文献   

4.
不同沉积环境及成熟度干酪根的碳氢同位素地球化学特征   总被引:13,自引:0,他引:13  
王万春 Schid.  M 《沉积学报》1997,15(A12):133-137
干酪根的碳同位素组成与源岩有无相关性存在不同认识,此次研究表明,在陆相沉积条件下,腐泥干酪根相对富集轻碳同位素^13C,腐殖型干酪根相对富集重碳同位素13C。热模拟实验表明,热演化过程对干酪根碳同位素产生明显影响,但其H/C原子比热演化程度增高而减小。  相似文献   

5.
天然气气-源对比的地球化学研究   总被引:7,自引:0,他引:7  
气-源对比是天然气勘探开发和油气理论研究的重要课题,同位素地球化学是气-源对比的重要手段,尤其是碳、氢稳定同位素和稀有气体同位素已经被广泛应用于烃源岩、母质环境、源岩热演化程度、成藏过程和天然气混源判识,系统的介绍了利用碳、氢以及稀有气体同位素判识天然气成因来源,利用甲烷碳同位素与源岩热演化程度数学模式进行气源追索, 利用甲烷氢同位素及其空间分布判识母质环境和成藏过程,利用稀有气体同位素判识是否深部来源气体并利用其年代积累效应进行气-源对比等方法.  相似文献   

6.
气-源对比是天然气勘探开发和油气理论研究的重要课题,同位素地球化学是气-源对比的重要手段,尤其是碳、氢稳定同位素和稀有气体同位素已经被广泛应用于烃源岩、母质环境、源岩热演化程度、成藏过程和天然气混源判识,系统的介绍了利用碳、氢以及稀有气体同位素判识天然气成因来源,利用甲烷碳同位素与源岩热演化程度数学模式进行气源追索,利用甲烷氢同位素及其空间分布判识母质环境和成藏过程,利用稀有气体同位素判识是否深部来源气体并利用其年代积累效应进行气-源对比等方法。  相似文献   

7.
本文旨在指出,测定^12C和^13C甲烷的氘取代模式的分析技术的发展,可能导致获得更好的有关各主要甲烷源类型源强度分布的约束条件。测定甲烷同位素组成的传统方法,要求将甲烷分子燃烧成CO2供做δ^13C分析,将伴生的水还原为H2供做δD分析。当只利用δ^13C-CH4和δD-CH4(甚至还有δ^14C-CH4)时,甲烷源的归属问题并未根本解决。源类型比每种源类型的独特示踪剂要多。如果同位素分析不用经  相似文献   

8.
我国煤的稳定同位素组成特征   总被引:2,自引:0,他引:2  
总结了煤及其煤化作用产物稳定同位素地球化学研究成果。煤的δ^13C值主要在-22.5‰~-25.5‰之间,中值为-24.4‰。煤化作用及地质年代影响极微,但煤岩显微组分对δ^13C值有明显影响,壳质组含量增加,煤的δ^13C值变轻。煤的热模拟演化产物δ^13C值;甲烷在液态烃产出峰值处有最烃的碳同位素组成,液态烃与煤有相似的δ^13C值,其族组分中烷烃部分随温度增高,δ^13C值有变重的趋势。煤的  相似文献   

9.
煤岩及其主显微组份热解气碳同位素组成的演化   总被引:13,自引:2,他引:13  
模拟实验是有机地球化学研究的重要组成部分 ,也是油气地球化学研究的重要手段。本文通过煤岩及其主要显微组分的热解成气模拟实验产物的组分和同位素组成分析 ,补充和完善了前人对煤岩热解气同位素组成分布的一些认识。同时 ,对比研究了煤型气与煤岩热解气的碳同位素分馏特征 ,结果表明两者具有良好的一致性 ,认为可以通过精细的热解模拟来提供不同含煤沉积盆地煤型气的判识指标 ,而模拟气与天然气碳同位素组成的对比 ,关键是对同位素分析资料的处理。在模拟系列产物碳同位素分析基础上 ,获得了单一成因来源天然气甲烷、乙烷碳同位素组成与演化程度之间的关系式以及演化过程中甲烷碳同位素之间的关系式 ,这些结果会对混源气的判识有重要意义。  相似文献   

10.
中国东部地幔CO2流体包裹体的碳同位素初步研究   总被引:21,自引:2,他引:21  
樊祺诚  储雪蕾 《地球化学》1996,25(3):264-269
采用分步加热爆裂法收集中国东部11个地点的新生代玄武岩中13个富CO2流体包裹体捕捞体(包括12个橄榄岩和1个麻粒岩)的CO2,做了碳同位素测定,800℃的δ^13C主要集中分布于-16.0‰--22.0‰,1100℃的δ^13C主要集中分布于-21.0‰-29.0‰。初步结果表明,地幔演化不同阶段的流体CO2碳同位素组成不同。  相似文献   

11.
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.  相似文献   

12.
Well investigated platforms have been selected in each continent, and the history of Cretaceous transgressions and regressions there is concisely reviewed from the available evidence. The factual records have been summarized into a diagram and the timing of the events correlated between distant as well as adjoining areas.On a global scale, major transgressions were stepwise enlarged in space and time from the Neocomian, via Aptian-Albian, to the Late Cretaceous, and the post-Cretaceous regression was very remarkable. Minor cycles of transgression-regression were not always synchronous between different areas. Some of them were, however, nearly synchronous between the areas facing the same ocean.Tectono-eustasy may have been the main cause of the phenomena of transgression-regression, but certain kinds of other tectonic movements which affected even the so-called stable platforms were also responsible for the phenomena. The combined effects of various causes may have been unusual in the Cretaceous, since it was a period of global tectonic activity. The slowing down of this activity followed by readjustments may have been the cause of the global regression at the end of the Cretaceous.  相似文献   

13.
The Afyon stratovolcano exhibits lamprophyric rocks, emplaced as hydrovolcanic products, aphanitic lava flows and dyke intrusions, during the final stages of volcanic activity. Most of the Afyon volcanics belong to the silica-saturated alkaline suite, as potassic trachyandesites and trachytes, while the products of the latest activity are lamproitic lamprophyres (jumillite, orendite, verite, fitztroyite) and alkaline lamprophyres (campto-sannaite, sannaite, hyalo-monchiquite, analcime–monchiquite). Afyon lamprophyres exhibit LILE and Zr enrichments, related to mantle metasomatism.  相似文献   

14.
正20140751 Guo Xincheng(Geological Party,BGMRED of Xinjiang,Changji 831100,China);Zheng Yuzhuang Determination and Geological Significance of the Mesoarchean Craton in Western Kunlun Mountains,Xinjiang,China(Geological Review,ISSN0371-5736,CN11-1952/P,59(3),2013,p.401-412,8  相似文献   

15.
正20141058 Chen Ling(Key Laboratory of Mathematical Geology of Sichuan Province,Chengdu University of Technology,Chengdu610059,China);Guo Ke Study of Geochemical Ore-Forming Anomaly Identification Based on the Theory of Blind Source Separation(Geosci-  相似文献   

16.
SEISMIC GEOLOGY     
正20141334 Chen Kun(Institute of Geophysics,China Earthquake Administration,Beijing100081,China);Yu Yanxiang Shakemap of Peak Ground Acceleration with Bias Correction for the Lushan,Sichuan Earthquake on April20,2013(Seismology and Geology,ISSN0253-4967,CN11-2192/P,35(3),2013,p.627-633,2 illus.,1 table,9 refs.)Key words:great earthquakes,Sichuan Province  相似文献   

17.
正20141624 Cai Xiongfei(Key Laboratory of Geobiology and Environmental Geology,Ministry of Education,China University of Geosciences,Wuhan 430074,China);Yang Jie A Restudy of the Upper Sinian Zhengmuguan and Tuerkeng Formations in the Helan Mountains(Journal of Stratigraphy,ISSN0253-4959CN32-1187/P,37(3),2013,p.377-386,5 illus.,2 tables,10 refs.)  相似文献   

18.
PALEONTOLOGY     
正20142263Lü Shaojun(Geological Survey of Jiangxi Province,Nanchang 330030,China)Early-Middle Permian Biostratigraphical Characteristics in Qiangduo Area,Tibet(Resources SurveyEnvironment,ISSN1671-4814,CN32-1640/N,34(4),2013,p.221-227,2illus.,2tables,22refs.)Key words:biostratigraphy,Lower Permian,Middle Permian,Tibet  相似文献   

19.
正20142560Hu Hongxia(Regional Geological and Mineral Resources Survey of Jilin Province,Changchun 130022,China);Dai Lixia Application of GIS Map Projection Transformation in Geological Work(Jilin Geology,ISSN1001-2427,CN22-1099/P,32(4),2013,p.160-163,4illus.,2refs.)  相似文献   

20.
GEOCHEMISTRY     
正20140692 Duo Tianhui(No.402 Geological Team,Exploration of Geology and Mineral Resources of Sichuan Authority,Chengdu611730,China);Wang Yongli Computer Simulation of Neptunium Existing Forms in the Groundwater(Computing Techniques for Geophysical and Geochemical Exploration,ISSN1001-1749,CN51-1242/P,35(3),  相似文献   

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