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华南绍兴-恩平富碱侵入岩带的厘定及其动力学意义初探 总被引：18，自引：5，他引：18
根据野外地质及室内岩相学、矿物成分和岩石化学的研究，从华南腹地厘定了一条重要的中生代NE向富碱侵入岩带－绍兴－恩平富碱侵入岩带。该岩带全长约1400km，宽100－150km，不仅发育有狭义的碱性岩（方沸黑云橄榄黄长岩、白榴黄长煌斑岩、霞石正长岩、霓辉石正长岩、黑榴石正长岩和含霓石石英正长岩）和碱性花岗岩（钠闪石花岗岩、霓辉石钠闪石花岗岩），还发育有大量的正长岩类－二长岩类－碱长花岗岩或晶洞钾长花岗岩。这些富碱侵入岩主要形成于晚中生代。绍兴－恩平燕山期富碱侵入岩带的厘定将对研究华南中生代的动力学的背景与演化具有重要的意义。 相似文献
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金沙江—红河富碱侵入岩带岩石—矿物学及岩石化学特征 总被引：4，自引：0，他引：4
金沙江－红河富碱侵入岩带,是我国两条著名的富碱侵入岩带之一,也是我国最重要的铜（钼）、金（铅锌）成矿带。因此,对该带内岩石学、矿物学及岩石化学的深入研究,将有助于在该岩带内找寻更多的大中型矿床。 相似文献
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云南三江地区富碱侵入岩与煌斑岩的同源性 总被引：8，自引：1，他引：8
云南三江地区富碱侵入岩与煌斑岩的同源性金志升黄智龙朱成明（中国科学院地球化学研究所，贵阳５５０００２）关键词三江地区富碱侵入岩煌斑岩同源性三江地区富碱侵入岩带（亦称哀牢山－金沙江富碱侵入岩带）是世界上著名的富碱侵入岩带之一，前人对该区富碱侵入岩进行过... 相似文献
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北山—阿拉善地区二叠—三叠纪富碱侵入岩的岩石学特征 总被引：11，自引：2，他引：11
甘肃北山－内蒙古阿拉善地区发育有一套以正长岩、石英正长岩、霓辉正长岩、霓霞正长岩类为代表，包括碱性辉长岩、二长岩、石英二长岩、碱长花岗岩和碱性花岗岩等类岩石在内的富碱侵入体。本文总结了它们的空间分布、形成时代、产状、岩石组合和岩石化学特征；指出它们具有近东西向的分布特征，主体形成于二叠－三叠纪时期，具有富碱、碱性岩类的岩石化学特征，构成一条富碱侵入岩带；认为其时空分布特点与华北地台、塔里木地台北缘及邻区碱性岩带一致，是华北－塔里木北缘及邻区巨型碱性岩带的重要组成部分。 相似文献
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华北克拉通北部地区古-中元古代富碱侵入岩年代学及意义 总被引：9，自引：15，他引：9
本文报道华北克拉通北部燕辽三叉裂堑系和辽-吉拗拉谷内一系列古-中元古代富碱侵入岩的锆石U-Pb年龄。这些岩体整体呈近东西向分布，与该地区同期发育的其他非造山球斑花岗岩、斜长岩和大红裕组火山岩都形成于拉张性构造环境，并构成了一条长近千公里的迄今国内外最古老的富碱侵入岩带。该富碱侵入岩带具有东部较老（〉1．8Ga）和西部年轻（1．7Ga左右）的特点，它提供了华北克拉通在1．85—1．70Ga期间处于裂解构造格局的最好证据，丰富了全球性前寒武纪超大陆裂解的研究内容。 相似文献
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岩浆矽卡岩及其矿床 总被引：19，自引：0，他引：19
岩浆矽卡岩是由钙硅酸盐熔（流）体或钙矽卡岩质岩浆贯入结晶或／和隐爆团结（结晶）形成的。主要呈脉状体，少数呈角砾岩筒（带），受断裂、裂隙构造控制，可产于各类不同岩石（层）中。岩浆矽卡岩与富碱中基－中酸性侵入岩密切共生，两者在主化学成分上具共轭、互补关系，组成特征的岩浆矽卡岩 －富碱（中基－中酸）侵入岩对。它们是深部高位岩浆房受钙质强烈混染的富碱闪长质岩浆发生不混溶分 离所衍生的两种不同性质的熔（流）体或岩浆的产物。与岩浆矽卡岩有关的各类矿床，主要是含同生铁氧 化物／硫化物液体的钙矽卡岩（矿）浆，伴随其成岩演变的产物，并构成了一个特殊的（岩）浆矽卡岩矿床系列。 相似文献
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滇西北与喜马拉雅期富碱斑岩有关的金矿成矿系统 总被引：4，自引：0，他引：4
滇西北地区广泛发育一套以喜马拉雅期为主，以富碱为特点的斑岩体(脉)，空间上具有以岩体(脉)集中区为单元，不同单元组成岩带，多岩带近平行产出的特征。富碱岩浆是地幔富碱质流体经由深大断裂上升至壳-幔混合带激发其岩石部分熔融的产物。金矿成矿与岩浆成岩一脉相承，形影相随，具有与富碱岩体完全一致的时空分布特点，体现了其成岩成矿受区域构造控制的一体化特征。成矿流体主要源于地幔，矿质则地幔与岩浆源区兼而有之。岩浆和岩浆活动是金矿成矿作用中深部矿质上升的载体和不断聚集的动力。由(近)EW向构造活动一地幔富碱质流体上升-壳-幔混合带内岩浆形成-富碱岩浆分异演化一流体成矿构成了统一的区域成矿系统，称之为该区与喜马拉雅期富碱岩浆活动有关的金矿(构造)-壳-幔(流体-岩浆)成矿系统。 相似文献
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在浙东沿海地区存在一条北北东向线型展布的、规模可观的富碱侵入岩带,岩带由碱长花岗岩和碱性花岗岩组成。其岩石地球化学特点是高硅(SiO2>76%)、富碱(N_2O K_2O>8.2%)、低铝(Al_2O_3<12.5%)、贫钙镁(CaO<0.4%、MgO<0.2%)、富集Rb、Th(U)、Nb(Ta)、Zr、Zn和Ga等元素;稀土元素模式曲线具缓右倾“V”字形,铕亏损强烈。上述地球化学特征与福建魁歧碱性花岗岩基本一致并类似澳大利亚东南Lachlan褶皱带A型花岗岩。研究表明,该富碱花岗岩带是燕山晚期岩浆演化后期产物,受区域深断裂控制,即可能是处于活动大陆边缘的深断裂在拉张条件下由深源富碱岩浆上侵而成。 相似文献
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Kenneth Hewitt Dr. 《GeoJournal》1992,27(1):47-60
The review examines mountain land risks, especially those that involve sudden, more or less localized bouts of damage and disasters. Geographers' studies to date have mainly dealt with natural hazards, emphasizing those like avalanches, large landslides or natural dams that are uniquely associated with mountain environments. Such work is briefly reviewed. Earthquake risks are then singled out to help define and discuss problems faced by this work. They are shown to depend strongly upon aspects of mountain environments other than seismicity. Human vulnerability appears to be mainly dependent upon socioeconomic and habitat conditions which, although they determine seismic impacts, may and usually do develop independent of it. Moreover, these ingredients of risk are most closely associated with, or definitive of, the mountain people and areas. They are most strongly influenced by human agency, both in deciding who and what are exposed to risk, and in actually increasing or decreasing unfavorable responses to earthquakes. Recent earthquake disasters in the mountains also record how rapid changes in these social and habitat conditions, rather than seismicity, are increasing the scale and altering the forms of damage. These changes in turn, however, are largely dependent upon developments, initiatives and penetration from outside the mountains, and responses of mountain people more or less enforced by them. The importance of so-called highland-lowland interactions, is even more obvious in the most destructive of human hazards discussed, those of war and other armed violence. Mountain lands and peoples are shown to have been subject to recurrent warring, and a disproportionate share of the deployment of state violence in this century. Most of the casualties are resident civilians. They have been usually threatened by other uses of armed violence, including insurgency and counter-insurgency warfare and genocidal actions by state forces. Refugees and expellees from war zones have included great numbers of mountain folk. Another fast growing hazard of the late twentieth century, not unrelated to war and militarism, the international trafficking in and addiction plagues of hard drugs, has a unique relation to mountains. The South American growers of the coca leaf, and Southwest and Southeast Asian growers of the opium poppy are mountain farmers. Their participation is bringing a range of severe risks to their high valleys, as well as benefits. Finally the paper addresses the conceptual problems brought about by the compounding of determinist assumptions in both mountain land and hazards research. These include not only environmental determinist notions, or related Neo-Malthusian and Social Darwinist ideas, but the various historicist ones of assumed technological, economic and political stages of development. It is argued that such social constructions of the problem of hazards and disaster are dubious, and have become a major impediment to understanding and risk mitigation. Alternative frameworks require more attention to the regional, state, and global patterns of influence shaping risk in mountain lands, but also to the human ecology of mountain societies taking account of matters to which the expediences of technocratic expertise have made us blind. 相似文献
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STEPHEN J. WESTHEAD 《Geology Today》1991,7(4):130-133
Parys Mountain, a small hill in north-east Anglesey, North Wales, has a very long history of copper mining, although exploration from 1955 onwards failed to locate deposits that were economic in modern terms. However, more detailed studies since the early 1980s have revealed a much more promising prospect. 相似文献
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贵州凯里亘古存在的活像饱经沧桑慈祥老人容貌的人面山和奇丽险峻雄伟香炉山及其多处人脸模样的象形地质景观,形态逼真罕见特殊,自然状态保存较好,环境优美协调,具有极高的拟生态和美学观赏价值,充分体现了贵州山地旅游资源的精彩魅力,应当成为"多彩贵州风,山地公园省"及凯里打造国际化旅游城市的核心旅游资源(地质)景观之一,加强与旅游资源大普查相关成果的整合开发,或将加快和提升凯里地区国际旅游城市的影响和品质。 相似文献
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The Holocene Activity Evidence of the Yema River-Daxue Mountain Fault in Western Qilian Mountain 总被引：2，自引：0，他引：2
Altyn Tagh fault controls the deformation characteristics of the northern margin of the Qinghai-Tibet Plateau.The sinistral slip rate of the eastern segment of the fault reduces gradually where the reduction transforms into the deformation within Qilian Mountain,forming a series of thrust faults and strike-slip faults.Among them,the Yema River-Daxue Mountain fault is one of the important structural transform faults in the study area.Based on the differences of the geometrical characteristics and activities,the fault is divided into four segments,the Yema River segment,the Shibandun segment,the Liushapo segment and the Baishitougou segment,among which the former three are Holocene active faults,and the Baishitougou segment belongs to late Pleistocene fault.The excavated trenches imply a total of 6 paleoearthquake events,and at least 4 events have occurred during Holocene,whose occurrence times are 8300±700 yr BP,6605±140 yr BP,4540±350 yr BP,2098±47 yr BP,respectively.The recurrence interval is 2600±600 yr BP that is close to the lapsed time of the last one,2098±47 yr BP,which suggests that the Yema River-Daxue Mountain fault is in a high risk of major earthquakes in the future.The vertical coseismic displacements of the four Holocene paleoearthquake events are 100 cm,42 cm,40 cm and 50 cm,respectively,the horizontal coseismic displacements are 5 m,4.5-5.5 m,5-8 m and 4-5.5 m,separately,and then the reference magnitude of the paleoearthquake events is conjectured to be M7.6±0.1. 相似文献
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Nigel J. R. Allan Dr. 《GeoJournal》1992,27(1):5-11
The celebrated 1972 Stockholm environmental conference focused attention on the condition of the world's environment. A twenty year retrospective summary is provided by the introduction and specialty papers on all facets of mountain society and habitat relationships. Theories, models and paradigms that guided mountain research are critically examined. Specific attention is given to the application of the ecology paradigm. Contemporary discoveries and developments about resource management in mountains are elucidated. Assessments of the mountain environment, including wildlife habitat, tourism and recreation, forests, hazards, deforestation, food plant biodiversity, risk and hazard, are provided by the specialty articles. These papers were prepared for the 1992 Earth Summit in Rio de Janeiro. 相似文献
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