http://www.sciencedirect.com/science/article/pii/S1674987112000266     

Yan Tang  Longkang Sang  Yanming Yuan  Yunpeng Zhang  Yunlong Yang 《地学前缘(英文版)》2012,3(5):647-660

Major,trace and rare earth element(REE) concentrations of Late Triassic sediments(finegrained sandstones and mudstones) from Hongcan Well 1 in the NE part of the Songpan-Ganzi Basin, western China,are used to reveal weathering,provenance and tectonic setting of inferred source areas. The Chemical Index of Alteration(CIA) reflects a low to moderate degree of chemical weathering in a cool and somewhat dry climate,and an A-CN-K plot suggests an older upper continental crust provenance dominated by felsic to intermediate igneous rocks of average tonalite composition.Based on the various geochemical tectonic setting discrimination diagrams,the Late Triassic sediments are inferred to have been deposited in a back-arc basin situated between an active continental margin(the Kunlun-Qinling Fold Belt) and a continental island arc(the Yidun Island Arc).The Triassic sediments in the study area underwent a rapid erosion and burial in a proximal slope-basin environment by the petrographic data. while the published flow directions of Triassic lurbidites in the Aba-Zoige region was not supported Yidun volcanic arc source.Therefore,we suggest that the Kunlun-Qinling tcrrane is most likely to have supplied source materials to the northeast part of the Songpan-Ganzi Basin during the Late Triassic.  相似文献   

考虑震源破裂过程的青海玉树地震震动图研究   总被引：4，自引：0，他引：4  

陈鲲  俞言祥  高孟潭  吕红山 《中国地震》2011,27(1):56-64

为了在缺少实时台站数据的情况下,研究震后地表地震动分布,本文尝试通过对震源做出某些约束,以提高震动图的精度.由于青海玉树地震的发震断层近似直立(倾向83°),震源破裂过程在时间和空间上呈明显的分区特征,分别考虑了地表破裂的线源发生模型和主震震级分解方法,用考虑了场地效应的震动图快速生成方法生成震动图.将两种方法生成的震动图与调查烈度比较.结果表明,基于震源破裂过程对主震震级进行分解,综合考虑各子事件生成震动图的方法,对震后的应急决策和灾情的快速评估是可行的.  相似文献   

龙潭水库诱发地震震源参数分析     

乔慧珍  张永久  任月霞  宫悦  赵敏 《四川地震》2011,(4):16-20

利用广西龙滩水库地震台网记录的数字地震波资料,用波谱分析方法计算了龙滩水库库区ML2．5—4．5级共计95个地震的震源参数。并对震源参数进行分析,结果表明：库区视应力的范围在0-3．5巴之间,2007年7月17日库区最大4．5级地震的视应力最大,为3．07巴。视应力随震级的增大呈幂函数增大趋势,两者的拟合关系为：σap...  相似文献   

青海玉树莫海拉亨铅锌矿床S、Pb、Sr-Nd同位素组成: 对成矿物质来源的指示——兼与东莫扎抓铅锌矿床的对比   总被引：7，自引：3，他引：4  

田世洪  侯增谦  杨竹森  刘英超  宋玉财  王富春  鲁海峰 《岩石学报》2011,27(9):2709-2720

青海玉树地区莫海拉亨铅锌矿床和东莫扎抓铅锌矿床均位于青藏高原金沙江缝合带和班公湖-怒江缝合带夹持的羌塘地体东北缘,是"三江"北段铜铅锌多金属成矿带铅锌矿床的2个典型代表。笔者曾通过对东莫扎抓铅锌矿床的S-Pb-Sr-Nd同位素组成特征研究,认为其成矿物质来源于沉积地层。本文在野外地质观察基础上,亦对莫海拉亨铅锌矿床的矿石矿物和重晶石进行了S同位素组成分析,对矿石矿物、脉石矿物和区域地层进行了Pb同位素组成分析,对脉石矿物进行了Sr-Nd同位素组成分析。分析结果表明,硫化物δ³⁴S值为-30.0‰~7.4‰,峰值为-18‰~-2‰,反映了总体富轻硫的特征,而重晶石δ³⁴S值为20.2‰~+24.2‰,来自于第三纪陆相盆地。宽的δ³⁴S变化可以解释为流体在盆地内活动期间与不同地层单元发生相互作用,从而继承了不同物质单元的S同位素特点,还原硫应主要来自于硫酸盐的细菌还原或者含硫有机质的热还原,反映硫来自沉积盆地。矿石矿物的²⁰⁶Pb/²⁰⁴Pb、²⁰⁷Pb/²⁰⁴Pb和²⁰⁸Pb/²⁰⁴Pb分别为18.298~18.694、15.298~15.721、38.169~38.894,而脉石矿物的²⁰⁶Pb/²⁰⁴Pb、²⁰⁷Pb/²⁰⁴Pb和²⁰⁸Pb/²⁰⁴Pb分别为18.418~18.672、15.418~15.719、38.403~38.845。矿石矿物和脉石矿物的Pb同位素组成介于区域上地壳Pb组成范围内,总体类似于MVT矿床,显示Pb等金属元素来源于上地壳岩石。脉石矿物的(⁸⁷Sr/⁸⁶Sr)_i、ε_Sr(t)、(¹⁴³Nd/¹⁴⁴Nd)_i和ε_Nd(t)分别为0.70851~0.70906、57.4~65.2、0.512265~0.512361、-6.5~-4.6。Sr-Nd同位素特征亦显示脉石矿物的物质来源于上地壳岩石。总体来说,莫海拉亨铅锌矿床的S-Pb-Sr-Nd同位素特征均与东莫扎抓铅锌矿床的一样,显示均来自沉积地层。并结合矿床地质特征和地球化学特征,讨论了莫海拉亨铅锌矿床和东莫扎抓铅锌矿床形成的动力学背景。  相似文献   

贝尔凹陷“源断势”对油成藏与分布的控制作用          下载免费PDF全文

付广  刘云燕 《地质科学》2011,46(4):1068-1078

为了研究贝尔凹陷源岩、断裂和势能场(简称“源断势”)控藏模式,采用油藏分布与源、断、势叠合方法,分别对油成藏、分布控制作用和控藏模式进行了研究,结果得到:1)南一段油源区控制着油藏形成与分布的范围;2)低势区控制着油聚集的部位;反向断裂翘倾隆起的低势区控制着南屯组和铜钵庙组油聚集成藏,反转构造低势区控制着大磨拐河组油聚...  相似文献   

郑州市地下水源热泵应用适宜性与环境影响分析     

田良河  刘新号  闫震鹏  焦红军  杨坡  谭菊萍 《城市地质》2011,6(4):51-56

本文在分析郑州市现有地温空调系统应用的基础上,从水文地质条件、浅层地温场特征、经济效益等方面分析了郑州市地下水源热泵应用的适宜性,研究了热泵运行对地下水环境的影响,认为地下水源热泵应用效果较好,经济社会效益明显,适宜推广应用,为城市地下水源热泵发展应用提供了依据。  相似文献   

世界主要深水含油气盆地烃源岩特征   总被引：2，自引：1，他引：1  

范玉海  屈红军  张功成  冯杨伟  关利群  雷露 《海相油气地质》2011,16(2):27-33

对墨西哥湾、巴西东部大陆边缘、西非被动大陆边缘、澳大利亚西北陆架、挪威中部陆架、南海等六个地区的22个深水含油气盆地烃源岩特征(主力烃源岩形成的时代、构造背景、沉积环境、类型、地球学化指标等)的综合研究结果表明,世界深水含油气盆地主力烃源岩主要集中在白垩系,其次为第三系和侏罗系;裂谷期烃源岩占绝对优势,其次为被动陆缘期...  相似文献   

广西合浦、南宁、宁明、百色盆地烃源岩有机地球化学特征与勘探潜力分析   总被引：2，自引：1，他引：1  

邵昌民  赵斌 《海相油气地质》2011,16(1):33-44

广西合浦、南宁、宁明等第三系盆地的主要烃源岩层与百色盆地一样,均是中始新统深湖-半深湖相暗色泥质岩层,特点是分布面积广,厚度大,有机质丰度高.有机碳含量多数大于2.0%,达到"好"到"最好"的评价标准.有机质成熟度多数处于低熟阶段,部分在成熟阶段.干酪根类型主要为Ⅱ1型.综合分析认为:合浦、南宁、宁明三个盆地都具有优质...  相似文献   

Oil-oil and oil-source rock correlations in the Alpine Foreland Basin of Austria: Insights from biomarker and stable carbon isotope studies     

Reinhard Gratzer  Achim BechtelReinhard F. Sachsenhofer  Hans-Gert LinzerDoris Reischenbacher  Hans-Martin Schulz 《Marine and Petroleum Geology》2011,28(6):1171-1186

The Alpine Foreland Basin is a minor oil and moderate gas province in central Europe. In the Austrian part of the Alpine Foreland Basin, oil and minor thermal gas are thought to be predominantly sourced from Lower Oligocene horizons (Schöneck and Eggerding formations). The source rocks are immature where the oil fields are located and enter the oil window at ca. 4 km depth beneath the Alpine nappes indicating long-distance lateral migration. Most important reservoirs are Upper Cretaceous and Eocene basal sandstones.Stable carbon isotope and biomarker ratios of oils from different reservoirs indicate compositional trends in W-E direction which reflect differences in source, depositional environment (facies), and maturity of potential source rocks. Thermal maturity parameters from oils of different fields are only in the western part consistent with northward displacement of immature oils by subsequently generated oils. In the eastern part of the basin different migration pathways must be assumed. The trend in S/(S + R) isomerisation of ααα-C₂₉ steranes versus the αββ (20R)/ααα (20R) C₂₉ steranes ratio from oil samples can be explained by differences in thermal maturation without involving long-distance migration. The results argue for hydrocarbon migration through highly permeable carrier beds or open faults rather than relatively short migration distances from the source. The lateral distance of oil fields to the position of mature source rocks beneath the Alpine nappes in the south suggests minimum migration distances between less than 20 km and more than 50 km.Biomarker compositions of the oils suggest Oligocene shaly to marly successions (i.e. Schoeneck, Dynow, and Eggerding formations) as potential source rocks, taking into account their immature character. Best matches are obtained between the oils and units a/b (marly shale) and c (black shale) of the “normal” Schöneck Formation, as well as with the so-called “Oberhofen Facies”. Results from open system pyrolysis-gas chromatography of potential source rocks indicate slightly higher sulphur content of the resulting pyrolysate from unit b. The enhanced dibenzothiophene/phenanthrene ratios of oils from the western part of the basin would be consistent with a higher contribution of unit b to hydrocarbon expulsion in this area. Differences in the relative contribution of sedimentary units to oil generation are inherited from thickness variations of respective units in the overthrusted sediments. The observed trend towards lighter δ¹³C values of hydrocarbon fractions from oil fields in a W-E direction are consistent with lower δ¹³C values of organic matter in unit c.  相似文献   

辽吉裂谷区铅锌金矿床S、Pb同位素组成特征及其地质意义   总被引：1，自引：0，他引：1  

马玉波  邢树文  张增杰 《地质学报》2013,87(9):1399-1410

辽吉裂谷区发育有众多大中型铅锌、金等多金属矿床,本文选择该地区的青城子榛子沟铅锌矿、白云金矿、五龙金矿、荒沟山铅锌矿和临江金矿作为研究对象,开展其矿石S、Pb同位素分析及其地质意义研究.数据显示榛子沟脉状铅锌矿δ34SCDT值介于-10.3‰～6.8‰之间,白云金矿δ34SCDT值介于-7.7‰～1.9‰之间,五龙金矿δ34 SCDT值介于0.8‰～3.6‰之间,荒沟山铅锌矿δ34 SCDT值介于6.7‰～17.8‰之间,临江金矿δ34 SCDT值介于0.7‰～1.5‰之间.研究区铅锌金矿床的矿石硫同位素主要有两种来源,其一来自于早期火山喷流沉积而成的地层硫,如青城子榛子沟层状铅矿矿体和荒沟山层状铅锌矿;另一类为后期岩浆硫,如青城子榛子沟脉状铅锌矿、白云金矿、五龙金矿以及临江金矿,此类岩浆硫形成过程中,对早期地层硫进行了混染.辽吉裂谷区典型多金属矿床矿石铅同位素值变化较大,206 pb/204 Pb值介于15.72～24.02,207pb/204 Pb值介于15.32～16.43,208pb/204 Pb值介于34.96～39.79,不同的矿床其比值具有不同特点.研究区铅同位素μ值相对集中且较大,显示铅源具有上地壳物质特征,但均受到了不同铅源的混合.榛子沟铅锌矿脉状矿体矿石铅和岩体铅均为混合铅源,矿石铅为上地壳与地幔的混合源铅,而岩体铅则是造山带铅与上地壳的混合源铅;白云金矿床矿石铅为造山带铅,而其岩体铅为上地壳与地幔的混合源铅;五龙金矿的铅同位素主要来源于元古宙造山带铅,同时又有幔源铅的混合;荒沟山铅锌矿矿石铅一组为正常铅,微偏钍铅,来源于统一矿源层,另外一组铅为放射成因铅,即铀铅,而临江金矿矿石铅属于放射成因铅.  相似文献