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1.
千里山花岗岩体地质地球化学及与成矿关系   总被引:51,自引:6,他引:51  
千里山花岗岩由似斑状黑云母花岗岩、等粒黑云母花岗岩和花岗斑岩组成。前两期岩体分别与两期钨多金属矿化有关,后一期与铅锌银成矿密切相联。两套花岗岩虽然均来自地壳,但取于不同源地。该岩体既为富F、Li,Rb,Be,Ga的BELIF花岗岩,又是富U,Th的高热花岗岩。  相似文献   

2.
浙闽沿海地区Ⅰ型—A型复合花岗岩体的地球化学及成因   总被引:11,自引:2,他引:9  
邱检生  王德滋 《岩石学报》1999,15(2):237-246
以鼓山-魁岐,青田和普陀山桃花岛三个典型岩体为例,系统研究了浙闽沿海I型-A型复合花岗岩体的地质和地球化学特征,研究结果表明:复合岩体中Ⅰ型与A型花岗岩在主量,微量和稀土元素特征上均存在明显变异。总体而言,A型花岗岩较之I型花岗岩富硅,富碱,贫钙,镁,铝,并具偏高的Rb/Sr,Rb/Ba,Ga/Al和偏低的LREE/HREE比值及显著的铕负异常。  相似文献   

3.
西昆仑山A型花岗岩带的发现及其地球动力学意义   总被引:18,自引:0,他引:18  
姜耀辉  杨万志 《地质论评》2000,46(3):235-244
西昆仑山发育一条醒目的A型花岗岩带,空间上与库地幔台展布范围相一致;它形成于印支晚期,与海西晚期Ⅰ型花岗岩共生;岩石相对富碱、LREE、Y、Nb、Zr,贫A1、Mg、Ca、Ba、Sr及过渡元素,又以SiO2含量范围宽(66%~77%)为其显著特色,与澳大利亚东部ChaelundiA型花岗岩极为相似。研究表明,花岗岩属A1型,形成于造山晚期相当稳定的拉张环境,是在岩石圈拆沉过程中侵位的。  相似文献   

4.
安徽茅坦A型花岗岩研究   总被引:22,自引:1,他引:21  
吴才来  黄许陈 《地质学报》1998,72(3):237-248
安徽茅坦花岗岩体是由4次侵入的细粒花岗岩、花岗斑岩、中粒花岗岩和粗粒花岗岩组成的复式岩体。各期次岩石具有高硅,富碱,富LREE、Y,Nb,Zr等大离子高电价元素及低Al、Mg,Ca、Ni、Cr,Ti,V的特点,与国内外A型花岗岩相似。岩石中副矿物种类聚多,以含碳硅石,磷钛矿等深源矿物为特征。锆石晶形以正锥面(111)和四方柱面(110)最为发育,与一般I型花岗岩有明显的差异。研究表明,该复式岩体为  相似文献   

5.
武夷山高溪和富城花岗岩体地球化学及其与铀成矿的关系   总被引:6,自引:2,他引:6  
从成矿地质条件分析,武夷火山铀成矿带中的主要铀矿床的共同点是都具有花岗岩基底岩石。选择富城和高溪两花岗岩体进行地球化学研究。这两个岩体均为复式岩基,其主体岩石都形成于印支晚期(高溪:214.6Ma;富城:203~226Ma)。岩体中的长石为微斜长石;黑云母为铁云母和铁叶云母。岩石化学表现为富硅、偏碱和铝过饱和的特征。微量元素Co、Ni、Cr、Sr、Ba含量和Sr/Ba比值较低,Rb、Nb、Pb、Zn的含量和Rb/Sr比值高。稀土总量较高,轻稀土富集,轻、重稀土的比值高,并有强烈的铕亏损。高溪和富城两岩体的初始锶同位素组成高(分别为0.71239和0.7198),钕同位素组成低(-6.62~-12.84),这些表明高溪岩体属改造型花岗岩。两岩体中活性铀的比例高,特别是在蚀变作用中活性铀的比例增加。铅同位素追踪研究表明,在蚀变过程中岩体中的铀发生了大量的丢失。矿石铅同位素和岩体铅同位素都位于造山带的演化线附近,且矿石铅、火山岩铅、花岗岩铅及基底变质岩铅同位素组成呈线性关系,据此认为高溪和富城花岗岩体分别是形成570和6722矿床主要铀源体之一  相似文献   

6.
苏北牛山片麻状A型花岗岩及其成因   总被引:5,自引:3,他引:2  
苏北牛山片麻状花岗岩形成于震旦期,富含碱性长石,普遍含有碱性镁铁矿物,具有高硅、富碱、低铝、贫水,富含Nb、Zr、Y、Ga、REE及Eu明显亏损等特征,为A型花岗岩。其Y/Nb、Yb/Ta、Ce/Nb等比值较高,Ga×104/Al和碱度较低,属A2亚型花岗岩。它是苏胶造山带在晋宁期碰撞造山后的拉张环境下,由地幔热流上涌,致使下地壳岩石部分熔融,产生的岩浆于中地壳侵位而形成。  相似文献   

7.
张宏飞  骆庭川 《现代地质》1994,8(4):453-458
扬子克拉通北缘的铁船山岩体形成于新元古代,其岩石类型为霓石-钠铁门石花岗岩,岩石富碱质、St、Fe、REE和高场强元素,而贫Al、Ca、Mg、Sr、Ba、Co、Ni等组分,δEu=0.20,A/KNC=0.85,K2O+Na2O/Al2O3=1.09,A·R=9.28,岩石属典型的A型花岗岩,Nd、Sr和O同位素示踪反映其成岩物质来自于壳幔混合源区。根据区域地质背景的综合分析,岩体形成于活动陆缘的张裂构造环境,属活动板块边缘拉张型花岗岩。  相似文献   

8.
浙闽沿海地区I型-A型复合花岗岩体的地球化学及成因   总被引:28,自引:7,他引:21  
《岩石学报》1999,15(2):88
以鼓山-魁岐、青田和普陀山-桃花岛三个典型岩体为例,系统研究了浙闽沿海I型-A型复合花岗岩体的地质和地球化学特征。研究结果表明:复合岩体中I型与A型花岗岩在主量、微量和稀土元素特征上均存在明显变异。总体而言,A型花岗岩较之I型花岗岩富硅、富碱、贫钙、镁、铝,并具偏高的Rb/Sr、Rb/Ba、Ga/Al和偏低的LREE/HREE比值及显著的铕负异常。两类花岗岩的Nd、Sr同位素组成均具有壳幔混熔岩浆的特点,但仍存在一定的变异。上述变异既有岩浆分异演化的影响,又有幔源岩浆卷入的贡献,在不同的复合岩体中起主导作用的因素各不相同。通过对岩石产出动力地质背景的全面分析,结合本区不同复合岩体中二类花岗岩具不同地球化学变异特点的地质事实,提出浙闽沿海I型-A型复合花岗岩是区域构造应力、断裂构造、幔源岩浆卷入和岩浆分异演化多种因素综合作用的结果  相似文献   

9.
福建将乐一带白云母化花岗岩成因的初步探讨   总被引:1,自引:0,他引:1  
游天寿  黄新鹏 《福建地质》1989,8(3):225-234,T001
本文以野外地质学、岩石学、岩石化学及微量元素、稀土元素地球化学等大量的实际资料为基础,从白云母化花岗岩的形成方式、物质来源和岩体形成的构造环境等方面来探讨将乐一带白云母化花岗岩的成因问题。论证了福建加里东期白云母化花岗岩是地壳深部硅铝质重熔的花岗岩,具有典型的岩浆型花岗岩特征。将乐一带白云母化花岗岩形成于加里东旋迥地槽回返封闭的晚期,因碰撞而闭合所产生的强烈褶皱促使地壳增厚,深部温度升高,从而局部产生重熔形成富铝花岗岩浆,沿构造上侵定位于震旦-寒武纪变质岩中。属陆-陆碰撞后花岗岩。  相似文献   

10.
广州-佛冈地区显生宙花岗岩类Nd-Sr同位素示踪研究   总被引:3,自引:1,他引:2  
广州-佛冈地区显生宙花岗岩类岩体ISr为0.7016 ̄0.7391,Nd同位素T2DM值在1.17 ̄2.27Ga之间。广佛地区极可能具有统一的属华夏古陆一部分的元古代基底,其Nd同位素T2DM值为2.11 ̄2.27Ga。具低T2DM值(1.17 ̄1.35Ga)的古生代和中生代花岗岩类岩体的存在,表明广佛地区在古生代和中生代有一定的地壳增长,相应花岗岩岩体的成岩物质有幔源成分的加入,其中燕山晚期的地  相似文献   

11.
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.  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.
Robert L. Linnen   《Lithos》2005,80(1-4):267-280
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.  相似文献   

15.
正20140876 Gao Junbo(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,China);Yang Ruidong Study on the Strontium Isotopic Composition of Large Devonian Barite Deposits from Zhenning,Guizhou Province(Geochimica,  相似文献   

16.
METALS DEPOSITS     
正20141470 Chai Lu(Shenyang Institute of Geology and Mineral Resources,CGS,Shenyang110034,China);Zhu Qun Distribution of Significant Metal Mineral Resources the in Adjacent Areas of China,Russia and Mongolia(Geology and Resources,ISSN1671-1947,CN21-1458/P,22(5),2013,p.397-402,2 illus.,3 tables,20 refs.)Key words:metal ores,China,Russia,Mongolia  相似文献   

17.
GEOPHYSICS     
正20141944Bao Hanyong(Research Institute of Exploration and Development,Jianghan Oilfield,SINOPEC,Wuhan 430223,China);Guo Zhanfeng Tectonic-Thermal Evolution of the Subei Basin since the Late Cretaceous(Geological Journal of China Universities,ISSN1006-7493,CN32-1440/P,19(4),  相似文献   

18.
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   

19.
正20142512Chen Xiaoan(Jiangxi Provincial Research Institute of Soil and Water Conservation,Nanchang 330029,China);Yang Jie Distribution Characteristics and Causes of Collapse Erosion(Journal of Mountain Research,ISSN1008-2786,CN51-1516/P,31(6),2013,p.716-722,2illus.,7tables,14refs.)  相似文献   

20.
SEISMIC GEOLOGY     
正20140644Cao Ying(Earthquake Administration of Yunnan Province,Kunming 650224,China);Wu Xiaoping Research on Structural Stress Field Basing on Focal Mechanism Solutions Data in Sichuan-Yunan Area(Journal of Seismological Research,ISSN1000-0666,CN53-1062/P,36(2),2013,p.165-172,6illus.,2tables,16refs.)  相似文献   

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