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依托青海省矿产地质志研编项目,在收集矿产勘查、科研成果资料以及调研典型矿床的基础上,对青海省铁矿时空分布、成矿系列和成矿模式进行了研究,取得以下主要成果:1)青海省铁矿床主要形成于元古代、寒武纪—奥陶纪和三叠纪,自北向南成矿时代由老变新,空间上主要分布于祁连、东昆仑构造带,祁连构造带以产出寒武纪—奥陶纪海相火山-沉积型铁矿床为特色,东昆仑构造带主要产出元古代沉积变质型和三叠纪接触交代矽卡岩型铁矿床;2)将青海省铁矿床划分为九个矿床成矿系列;3)厘定了青海省主要类型铁矿床产出的构造环境,认为元古代沉积变质型铁矿产于大陆边缘,寒武纪—奥陶纪及二叠纪—三叠纪海相火山-沉积型铁矿产于大陆裂谷、岛弧或弧后盆地,三叠纪接触交代矽卡岩型铁矿产于碰撞-后碰撞造山带;4)概述了九个系列矿床成矿特征,建立了元古代沉积变质型、寒武纪—奥陶纪海相火山-沉积型、二叠纪—三叠纪海相火山-沉积型、三叠纪接触交代矽卡岩型4个主要矿床成矿系列的成矿模式。 相似文献
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中国前寒武纪铁矿床时空分布和演化特征 总被引：17，自引：2，他引：15
前寒武纪是中国铁矿重要成矿期,该时期的铁矿资源／储量占全国的656％。前寒武纪铁矿床类型可分（火山）沉积变质型铁矿床、与火山-侵入活动有关的铁矿床、沉积型铁矿床、复合成矿作用型铁矿床和岩浆型铁矿床五类,再细分为条带状铁建造铁矿床、与细碧角斑质火山-侵入活动有关的中浅变质铁矿床、沉积-变质热液改造型铁矿床等8个亚类。（火山）沉积变质型铁矿床是前寒武纪铁矿床的主要类型,其储量、矿产地和开采量均占全国首位,其中最主要的是条带状铁建造铁矿床亚类,是前寒武纪的特征类型,是仅发育在前寒武纪时期的铁矿床。中国最古老的铁矿床形成于古太古代,新太古代是中国铁矿最重要的形成时期,此期间形成铁矿的储量约占全国铁矿总储量50％,矿床类型是与绿岩带有关的阿尔戈马型条带状铁建造铁矿床。中国前寒武纪铁矿床主要分布在中国东部、陆块区和陆块边缘和内部的裂谷中,其成矿规模、成矿区域、成矿类型和成矿演化特点明显。 相似文献
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河南信阳高梁店乡铁铜矿矿区位于华北地台南缘陆壳增生带——东秦岭加里东构造岩浆带的东端,主体由二郎坪群火山、沉积、构造杂岩带构成.矿体主要呈透镜状产出于二郎坪群大栗树组第二岩性段斜长角闪(片)岩中,具有明显的层控特征,铁矿石中常见似层状黄铜矿,似层状矽卡岩化和硅化为近矿围岩的主要蚀变类型.根据矿床地质-地球化学特征,结合矿石的矿物共生组合、硫同位素组成及流体包裹体成分及特征,认为该矿床的形成与古生代二郎坪群的海相火山喷发沉积密切相关,早期的海底火山喷发形成了大量的玄武岩质熔岩(富含铁、铜),在火山喷发旋回的间歇期,形成了喷流沉积型的铁矿层和碳酸盐岩层;晚期受加里东末期-海西早期区域变质作用的影响,造成矿区基性火山岩变质形成层状矽卡岩,同时叠加了热液成因的浸染状、脉状铜铁矿化.故该矿床属于火山-沉积变质改造型含铜磁铁矿床. 相似文献
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新疆阿尔泰克兰盆地金属矿床地质特征及成矿作用 总被引：2，自引：1，他引：1
在前人工作基础上,文章综述了新疆阿尔泰克兰盆地金属矿成矿背景和地质特征。其赋矿地层主要为上志留统—下泥盆统康布铁堡组变质火山沉积岩系,少数为中-上泥盆统阿勒泰组变质火山沉积岩系。成因类型划分为海相火山岩型、矽卡岩型、Sedex型、造山型和伟晶岩型5种类型,其中海相火山岩型为主要类型,进一步划分出VMS型、火山热液型、火山沉积型和矿浆-火山热液型4个亚类型。根据同位素测年结果,矿床成矿时代分为3期:早泥盆世(410~389 Ma),是主要成矿期,与海相火山作用有关,主要形成海相火山岩型,少数矽卡岩型矿床;晚石炭世—二叠纪(320~258 Ma),主要形成与岩浆期后热液、伟晶岩或构造热液活动有关的矽卡岩型、伟晶岩型稀有金属矿和造山型金矿;早-中三叠世(248~232 Ma),形成少量伟晶岩型稀有金属矿。硫同位素表明矽卡岩型铁矿的硫来自与成矿有关的花岗岩;火山沉积岩型和矿浆-火山热液型铁矿的硫除来自火山岩外,还有细菌还原海水硫和闪长岩;VMS型矿床的硫主要是海水硫酸盐细菌还原硫和来自岩浆(来自火山喷气或火山作用)。 相似文献
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正2矿产资源概况2.6金属矿产资源阿富汗金属矿产资源较为丰富,铁矿、铬矿、铜矿和锡矿等比较突出,有的在中亚地区还具有一定代表性。(1)铁矿资源阿富汗有铁矿床、铁矿点近60处,主要矿床类型为沉积变质型和矽卡岩型、热液型。沉积变质型铁矿分布最广、规模较大,其资源储量占全国资源储量的80%以上,而矽卡岩型铁矿和热液型铁矿,虽然矿石品位 相似文献
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沉积变质型铁矿成矿条件及富铁矿形成机制 总被引：1，自引：0，他引：1
我国铁矿床类型有沉积变质型、岩浆型、接触交代 热液型(矽卡岩型)、火山岩型、沉积型和风化淋滤型6种,以沉积变质型最为重要。我国的沉积变质型铁矿床主要分布于华北克拉通,以鞍山式铁矿为代表,沉积时代为新太古代末,为阿尔果马型条带状铁建造 (BIF)变质而成;吕梁地区的袁家村式铁矿为苏比利尔型BIF变质而成,BIF沉积时代为2. 384~2. 210 Ga或新太古代末;舞阳、霍邱地区的沉积变质型铁矿可能为苏比利尔型BIF变质产物,BIF沉积时代分别为2. 473~2. 468 Ga、＜2. 54 Ga。BIF的形成与缺氧环境向大氧化事件初期的层化海洋环境过渡有关,海水中巨量溶解的铁质部分氧化,在初始层化海洋氧化还原界面附近的浅海环境以胶体形式沉淀。我国的BIF遭受区域变质变形作用,成为条带状磁铁石英岩,作为沉积变质型铁矿开发利用。BIF经历后期流体改造可形成富铁矿,形成机制有“去硅富铁”、“铁质活化再富集”和“去碳酸盐富铁”3种,弓长岭富铁矿的成矿年龄为1. 85 Ga左右,由BIF“去硅富铁”而成;齐大山富铁矿可能形成于2. 5 Ga,由BIF“铁质活化再富集”而成;袁家村富铁矿形成于1. 41~1. 34 Ga,可能由含碳酸盐的BIF“去碳酸盐富铁”而成。 相似文献
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辽宁鞍本地区沉积变质型富铁矿的成因：Fe、Si、O、S同位素证据 总被引：2，自引：0，他引：2
辽宁鞍本地区是我国最重要的鞍山式沉积变质型(BIF)铁矿矿集区,弓长岭铁矿是我国唯一的由鞍山式贫铁矿经后期热液改造形成的大型磁铁富矿.本文在前人工作基础上,对比研究了鞍本地区贫铁矿、富铁矿和蚀变围岩的铁、硅、氧、硫同位素组成特征和空间变化规律,结合磁铁富矿的地质特征,对成矿流体的性质、来源、成矿作用和富矿成矿机制提出了新的认识.指出鞍本地区富铁矿的成矿作用与辽东地区古元古代造山运动结束后(1.85 Ga)地壳抬升引发的非造山岩浆侵入和热液活动有关,成矿溶液由大气降水演化形成,而非变质热液或混合岩化热液;成矿溶液淋滤了辽河群蒸发盐地层中富13C碳酸盐、富34S石膏、CH4等成矿物质,成矿溶液具偏酸性弱还原特征;铁质活化再富集是鞍本地区富铁矿形成的重要机制,成矿溶液与贫铁矿及围岩反应使铁质以Fe2+形式活化迁移.温度降低、氧逸度升高或与大气降水混合是溶液中Fe2+氧化形成磁铁矿沉淀的主要原因;在Fe2+被氧化形成磁铁矿的同时,成矿溶液中的CH4被氧化形成石墨,与磁铁矿一起沉淀下来,形成含石墨磁铁富矿;溶液中SO42-被还原形成富34S黄铁矿. 相似文献
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Emily Keeble David I. Whiteside Michael J. Benton 《Proceedings of the Geologists' Association. Geologists' Association》2018,129(2):99-119
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
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The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts 总被引：4，自引：0，他引：4
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
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Muriel Rocher Stéphane Baize Stéphane Jaillet Edward Marc Cushing Yannick Lozac&#x;h Francis Lemeille 《Comptes Rendus Geoscience》2003,335(8):701-708
Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ1 roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003). 相似文献
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正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level 相似文献
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正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7), 相似文献
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正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci- 相似文献
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正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli- 相似文献
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正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.) 相似文献
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正20142002 Wei Hualing(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang065000,China);Zhou Guohua Element Content and Mineral Compositions in Different Sizes of Soil in Tongling Area,Anhui Province(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(11),2013,p.1861 相似文献