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1.
中国东部燕山期火山-岩浆大爆发   总被引:18,自引:0,他引:18  
中国东部燕山期存在惊天动地的火山-岩浆大爆发,形成了7条火山岩带,8种岩石系列和组合,构成了四大火成岩省。在近20×10^6a内有数百万立方千米的高温岩浆出地表,喷发速率约为0.03km^3/a对全球气候环境变化和生物灭绝产生巨大影响,火山-岩浆大爆发与成矿作用大集中是壳幔物质和能量大循环的必然结果,深部地幔柱地岩石圈的突变机制极大地控制了燕山期地质生态的大变革。  相似文献   

2.
浙江省萤石矿床区域成矿规律与找矿方向研究   总被引:2,自引:1,他引:1  
黄国成  张永山  程海艳 《矿床地质》2015,34(6):1209-1222
萤石矿是浙江省的优势矿种之一,储量在中国名列前茅。根据矿床成因可分为火山-次火山热液充填型、岩浆期后热液充填型和岩浆热液交代型3种类型。火山-次火山热液充填型萤石矿床主要分布于浙东南火山岩分布区,成矿作用与中生代火山活动关系密切;岩浆期后热液充填型和岩浆热液交代型萤石矿床主要分布于浙西北燕山期花岗岩周围,成矿作用与燕山期岩浆侵入活动密切相关。文章根据浙江省萤石矿床的成因类型、成矿作用、构造环境、成矿时代等特征,可将其归纳为2个成矿系列:与中生代火山-次火山热液有关的萤石矿床成矿系列和与中生代岩浆侵入作用有关的萤石矿床成矿系列。其中,与中生代岩浆侵入作用有关的萤石矿床成矿系列又可分为与燕山期中酸性岩浆期后热液充填作用有关的萤石矿床成矿亚系列及与燕山期中酸性岩浆热液交代作用有关的萤石矿床成矿亚系列。在此基础上,提出了2大萤石矿床成矿系列的找矿方向分别为浙东南晚白垩世火山断陷盆地边缘断裂、火山口环形和放射状断裂及浙西北高氟岩体。  相似文献   

3.
苗儿山岗岩复式岩基年代学研究的进展及时代划分方案   总被引:4,自引:0,他引:4  
徐伟昌  张运洪 《岩石学报》1994,10(3):330-337
华南苗儿山花岗岩复式岩基的岩浆活动时代可分为加里东晚期(368Ma)、海西期(260Ma)、印支期(218~197Ma)、燕山期(192~94Ma)。燕山期又可分为两个亚期;燕山早期第一阶段(19~168Ma);第二阶段(155~131Ma)和燕山晚期(115~94Ma)。岩浆活动与区域地壳运动及深部构造密切有关。  相似文献   

4.
中国东部燕山期岩石圈-软流圈系统大灾变与成矿环境   总被引:84,自引:9,他引:75  
中国东部在燕山期发生了岩石圈_软流圈系统(LAS) 大灾变事件, 并识别出被扰动的LAS的两种类型, 即在挤压造山环境下的岩石圈巨大减薄与巨大增厚作用; 它们分别对应相关的安第斯型和海西型成矿作用。大量的新生、热地幔物质和再活化的热的下地壳物质取代、加热和注入冷的岩石圈和地壳是燕山期成矿大爆发的基因和基本的深部环境。再活化和活动的岩石圈尺度的不连续带是成矿带的良好储矿空间。巨大的岩浆_流体_成矿系统是形成巨大矿集区的必需。从深部成矿环境来看, 中国东部具有巨大的找矿潜力  相似文献   

5.
大兴安岭中南段铜矿成矿背景及找矿潜力   总被引:25,自引:4,他引:21  
大兴安岭中南段主要铜矿类型为斑岩-热液脉型,其成矿与燕山早期浅定位中酸性侵入体有成因联系,成矿时代集中180Ma ̄160Ma,与中生代早期岩石圈伸展背景下幔源岩浆底侵-同熔-分异作用有关,由于其形成于区域大规模火山喷发之前,深部岩浆来不及进行彻底分异,对铜的大规模成矿不利。因此,寻找大型以上规模的铜矿床必须综合考虑岩浆条件和矿源层两个主要因素。本区大规模岩浆作用晚期(燕山晚期)形成的紫金山式铜矿应  相似文献   

6.
中国东南部地幔柱及其与中生代大规模成矿关系初探   总被引:21,自引:4,他引:21  
中国东南部是我国的钨锡铜金多金属矿床集中区,燕山期发生大规模成矿作用,研究大规模成矿的地球动力学背景显得尤为重要。本文结合前人的研究资料,初步讨论中国东南部地幔柱及其与中生代大规模成矿关系。通过对中国东南部地幔柱的地质和地球物理方面特征综合分析后,初步探讨了地幔柱构造的岩浆作用和成矿制约。本文认为中国东南部地幔柱不仅可能造成中生代火山─岩浆大爆发,而且可能与中生代大规模成矿有关。  相似文献   

7.
张丕富  吴锡生 《地质论评》1991,37(5):429-436
浙江治岭头金银矿床系燕山晚期火山热液作用之产物。随燕山期火山作用的演化,蕴藏在岩浆中的金、银等成矿物质逐渐进入岩浆后期热液中形成含矿热液。含矿热液沿火山塌陷断裂向上运移,由于物理化学障的作用,致使含矿热液大量涌人火山塌陷断裂的次一级张扭裂隙中成矿成晕。  相似文献   

8.
庐枞火山盆地位于长江中下游成矿带中段,中生代燕山期强烈的火山-潜火山岩浆作用孕育了盆地内的铀多金属成矿作用。研究表明,盆地内铀成矿是潜火山岩侵位后的地质事件,潜火山岩浆活动对铀成矿起主导作用。潜火山岩浆演化晩期的残余相富铀,在石英正长岩中形成晶质铀矿等高温矿物。结合岩石铀含量分析结果,笔者认为石英正长岩可构成铀源体,潜火山岩浆期后热液与铀源体相互作用,促成了成矿流体演化。早期流体以岩浆水为主,成矿期流体为岩浆水与大气降水混合的产物,成矿流体性质由碱性向酸性演化。温度降低及流体的混合作用,促使矿质在成矿有利空间卸载。  相似文献   

9.
早元古代角闪岩相大型韧性剪切带和叠加其上的中生代脆性张裂破碎带共同组成的复合构造是治岭头金矿主要的控矿构造。成矿热液主要来自燕山期火山-岩浆活动。成矿物质主要来自上地壳下部的重熔岩浆。中生代火山岩盖层是避免矿液逸散的必不可少的屏蔽层。矿床类型属于燕山期火山-岩浆热液成因的后韧性剪切带型金矿。  相似文献   

10.
通过矿田一些地质地球化学等成因依据的研究和长坡矿热水喷口的发现,提出区域地球化学场的存在,中元古界—下古生界原始矿源层的形成,泥盆纪海底火山—热水成矿作用、华力西—印支期大广地区石油的形成—迁移—聚积过程形成富含金属成矿物质的油气田,燕山期岩浆热液叠加改造成矿作用以及燕山期构造—岩浆作用破坏富含金属成矿物质的油气田而成矿等—系列地质作用在大厂地区地质历史上有机组合,形成大厂超大型矿床,而泥盆纪火山及海底热水作用、燕山期构造—岩浆作用则是主导成矿作用.  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.
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   

13.
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   

14.
Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.  相似文献   

15.
PALEONTOLOGY     
正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.)  相似文献   

16.
正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.)  相似文献   

17.
正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.)  相似文献   

18.
PETROLOGY     
正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus.,  相似文献   

19.
正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an  相似文献   

20.
正20141266Fan Chaoyan(Guangdong Provincial Key Laboratory of Mineral Resources and Geological Processes,Guangzhou 510275,China);Wang Zhenghai On Error Analysis and Correction Method of Measured Strata Section with Wire Projection Method(Journal of  相似文献   

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