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铝土矿是金属铝的主要来源,近年来,随着经济社会快速发展和城镇化逐步推进,中国铝需求量逐年走高。文章简要概括了铝土矿的分布特点、主要类型及主要资源国的铝土矿分布情况,着重介绍了最近几年铝土矿勘查开发的新进展,以深化对铝土矿空间分布、地质特征的认识,把握铝土矿的勘查开发趋势。根据矿石成因,铝土矿主要分为红土型和岩溶型两类,前者主要分布在非洲西部、南美洲北部、印度、东南亚及澳大利亚北部和西南部,后者主要分布在南欧、加勒比海地区、亚洲西部和中国。铝土矿勘查方面,在铝土矿储量大国中,几内亚、俄罗斯、澳大利亚主要以对大型成熟铝土矿山的扩边增储工作为主,巴西、加纳、牙买加等国则主要以勘探新区为主。铝土矿开发方面,目前全球铝土矿主要生产国为澳大利亚、几内亚和中国,2019年三国合计铝土矿产量约占世界总产量的70%。2020年上半年,受新冠肺炎疫情影响,主要金属价格出现恐慌性大幅下跌。虽然近期主要金属价格有震荡反弹趋势,但以美国、巴西、印度等为代表的世界主要经济体仍深陷疫情泥潭,英国、法国、意大利等欧盟国家仍面临较大防控压力,全球也存在爆发第二波疫情的可能,在此背景下,铝土矿勘查开发形势仍存在很大变数。 相似文献
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圭亚那地盾位于南美洲亚马孙克拉通的北部,其北部广泛发育太古宙典型的花岗岩-绿岩带,主要岩石组成为花岗岩、片麻岩和英云闪长岩,古元古代变质超基性-基性火山岩-侵入岩、其他变质火山岩等。由于独特的地质构造位置和复杂的构造演化历史,形成了良好的绿岩型金成矿地质背景,产生了大量的金矿床。通过总结圭亚那地盾北部绿岩带的岩石特征、成岩时代和构造演化历史,对委内瑞拉埃尔卡劳金矿、圭亚那欧迈金矿和苏里南罗瑟贝尔金矿进行典型矿床剖析,系统研究了该区绿岩带型金矿的成矿地质背景、成矿流体及成矿年代学特征,建立了区域绿岩带型金矿成矿模型,并在分析找矿要素的基础上,提出圭亚那地盾北部的金矿找矿方向。 相似文献
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委内瑞拉、圭亚那和巴西的圭亚那地盾的冲积金刚石的原始来源，已争论了很长时间。根据可靠证据认为，圭亚那地盾的金刚石至少有两个源区。第一个源区是该区大于200m厚的元古宙碎屑沉积层，称罗赖马群（Roraima）。但构成罗赖马群的金刚石原生来源和碎屑物质源尚不清楚。圭亚那地后金刚石的第二个源区是委内瑞拉西部的瓜尼亚莫（Guaniamo）地区含金刚石冲积矿床。金伯利岩指示矿物镁铝榴石（Pvrone）和石榴石、镁钛铁矿（Mgilmenite）出现在这些冲积物中。最近发现了原生的元古宙金伯利型源岩。但瓜尼亚莫金刚石的特征在整体上不同于罗赖… 相似文献
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六论贵州之铝土矿：——铝土矿矿床成因类型划分意见 总被引：4，自引：0，他引：4
本文在概述了国内者关于铝土矿矿床成因类型划分沿革之后，主要对贵州沉积类硬水铝石铝土矿矿床进行了初步的成因类型划分。根据铝土矿成矿时代、基底岩性、铝土矿含矿岩系剖面特征、主要矿石工业类型及成矿环境等认为，贵州铝土矿均属沉积类，其下划分为两个亚类和五个类型，即猫场型、后槽型、仙人岩型、凤王槽型和大竹园型。文中详细列举了１１个剖面的岩性及化学成分资料。本文仅供有关部门今后对我国铝土矿矿床进行全面、系统地 相似文献
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苏里南金矿主要位于圭亚那地盾古元古代花岗岩-绿岩带上,沿大型剪切带或断层带分布。通过实地调查、综合研究及结合前人资料的基础上初步认为当地主要有冲洪积型、残坡积型、剪切带(造山)型金矿等类型。剪切带型金矿与剪切构造活动同期或晚于构造变形期,与泛亚马逊造山期后钙碱性火山作用和深成侵入作用同期。根据罗斯贝尔金矿等典型矿床研究,苏里南金矿与圭亚那地盾其它造山型金矿成矿时代相近(2.023~1.955Ga),泛亚马逊主期的构造对金矿起到了导矿和容矿作用,同时提出苏里南金矿的主要找矿方向。 相似文献
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南美洲铁矿资源丰富、分布广泛、矿床规模大、矿石品位高、类型较齐全。从南美洲大地构造格架分析,分布在克拉通地盾区或其边缘的沉积-变质型铁矿和分布在安第斯海岸造山带的火山成因型铁矿最为重要,沉积-变质型铁矿主要形成于太古宙—元古宙,火山成因型铁矿主要形成于中新生代。综合研究分析,圈出10个铁矿重要成矿区带,主要分布在委内瑞拉的玻利瓦尔州,巴西的阿马帕州、帕拉州、米纳斯吉拉斯州、北里奥格兰德州、巴拉伊巴州、巴伊亚州、南马托格罗索州,玻利维亚的圣克鲁斯州,秘鲁的伊卡—阿雷基帕海岸带和智利的卡拉马—圣地亚哥海岸带等。通过对重要成矿区带内典型矿床的剖析,并采用统计分析方法总结南美洲铁矿成矿时空分布规律,为未来在该区寻找更多的铁矿资源提供参考。 相似文献
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Prof. Ulrich Petersen 《International Journal of Earth Sciences》1970,59(3):834-897
This paper discusses the broadscale distribution of some ore deposit types in South America, trying to discern possible relations with major geotectonic features. It does not cover all ore deposits but rather a selection based on available information, genetic types, geographic distribution, and a representation of deposit types which are either abundant or very rare in South America. Included are porphyry copper, zoned copper-zinc-lead-silver, contact-metasomatic, red-bed copper-uranium-vanadium, lead-zinc (including Mississippi Valley type), mercury, tin, pegmatite, carbonatite and alkalic complex, diamond, nickelcobalt-chromite-asbestos-talc, iron, bauxite, tungsten, titanium, uranium, gold, potash and phosphate deposits. Comparisons are made with the distribution of these deposit types in other continents, especially in North America and Africa. This leads to some speculations bearing on theories of ore genesis. The evidence suggests that upper crustal processes predominate in the formation of the majority of ore deposits considered (excepting carbonatites, alkalic complexes and diamond pipes). Also, the relative level of an orogenic belt exposed by erosion seems to be an important factor bearing on the presently known distribution of many ore deposit types. Furthermore, the fact that ore deposits of given types tend to be aligned along the Cordillera in more or less defined belts with changing chemical composition accross the Andes, which partake in all its inflections, and in patterns which are similar in North and South America, indicates that they are either dependent on the distribution of eugeosynclinal vs miogeosynclinal sediments in the original geosynclinal prism, or that their character is related to distance from the major batholitic masses or to shallow stocks and volcanic activity. The indicated correlation with sediment character and evaporites speaks in favor of modem concepts viewing hydrothermal fluids as mainly meteoric but heated and circulated largely by igneous activity. This study raises more questions than it can answer and calls attention to a number of problems requiring further research. From a practical point of view, this investigation reveals several possibilities for future exploration, as well as opportunities for further development of mineral resources in South America. Several countries could probably improve or diversify their mineral production significantly, thus raising the standard of living of their increasing population. Whereas in North America both Canada and the U.S.A. span from east to west the whole range of geological environments, from cratonic to geosynclinal and orogenic, in South America the distribución of countries is essentially either along the Cordillera or over shield areas, a fact of obvious geopolitical implications with regard to mineral resources. 相似文献
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西西非地区蕴藏着丰富的矿产资源,尤其以产出众多大型超大型的铝土矿、铁矿、金矿、金刚石矿等著称,在全球占有重要地位。矿床集中分布在三个构造域内,形成于不同的成矿期:(1)太古宙马恩(Man)地盾和雷圭巴特(Reguibat)地盾、古元古界莱奥(Leo)地盾及凯涅巴(Kéniéba)和卡伊(Kayes)构造窗,主要成矿事件包括在2.5-2.3Ga形成了多个巨型铁矿床;几乎所有金矿、斑岩型铜矿、铅锌矿和沉积型锰矿都形成于2.2-2.1Ga;原生金刚石矿床形成于两个时间段,分别是2.2-2.0Ga左右和中生代。(2)泛非期和海西期活动带成矿域,主要成矿事件包括前寒武纪2.1Ga左右以及680Ma左右发生的铁氧化物铜金矿床(IOCG)成矿事件,以及新元古代沉积型铁矿和磷矿。(3)克拉通内盆地和海岸盆地带,包括新生代在中生代辉绿岩之上发生的铝土矿化作用,新近纪/第四纪形成的砂矿床、鲕状铁矿床和沉积型磷矿。西非地区的矿产分布规律与成矿时代、赋矿岩石、区域构造密切相关,不同矿种区域集中分布特征明显。根据已发现的铁矿、铝土矿、金矿、金刚石矿等主要经济矿产的分布,结合区域地质背景等因素,在西非克拉通南部划分了3个重要成矿区:(1)马恩太古宙地盾铁、金刚石巨型成矿区;(2)莱奥古中元古界地盾(包括凯涅巴构造窗)金矿等巨型成矿区;(3)博韦(Bove)新元古-古生代盆地铝土矿巨型成矿区。这些巨型成矿区也是西非地区最重要的矿产地和成矿远景区。 相似文献
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Local economic development policies have surged in Brazil over the past decade—a major shift in this regionally diverse country of 27 states, over 5000 municipalities, and the largest economy in Latin America. We review the stylized facts, expected patterns and policy recommendations from the foundational studies in regional and urban economics. We then provide a summary of a more recent stream of scholarship focused on local economic development (LED) studies in developed and developing countries that have surged in the last 20 years. Based on this review, we then systemize the findings emerging from studies focused on analyzing local economic development policies in Brazil recognizing the distinctive contributions emerging from both the empirical and the case studies literatures. We identify key lessons for (and from) the Brazilian experience and conclude that Brazil and Latin American countries need a new generation of studies that undertake more rigorous evaluations of these policy experiments. Finally, we recommend steps to advance such research. 相似文献
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在市场经济条件下中国铝土矿的储量与产量可供性受价格波动影响明显。本文基于DCF财务现金流折现估值模型,编制2016—2020年中国铝土矿储量、产量与价格关系图,可直观地看到在不同市场价格、不同内部收益率时,2016—2020年中国铝土矿储量和产量供应能力,从而为我国编制铝土矿资源规划。通过分析可以看出:虽然眼下矿业形势低迷,但未来五年中国铝土矿仍然储量充沛、供应旺盛。已查明保有资源在2016年最大可供储量为31.82亿吨,最大可供产量为6 400万吨,到2020年最大可供储量为28.78亿吨,最大可供产量为7 300万吨。当务之急是合理布局并缩减过剩产能,促使铝土矿资源的开发利用健康可持续。 相似文献
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《Atmósfera》2014,27(1):61-76
The Carbon Tracker system will play a major role in understanding CO2 sinks and sources, gas exchange between the atmosphere and oceans, and gas emissions from forest fres and fossil fuels in Latin America and the Caribbean. This paper discusses the trends in carbon fluxes in the biosphere and ocean, as well as emissions from forest fres and fossil fuel use in the above-mentioned region, using the Carbon Tracker (CT) system. From 2000 to 2009, the mean carbon fluxes for the biosphere, fossil fuel use, wildfires and the ocean in Latin America and the Caribbean were −0.03, 0.41, 0.296, −0.061 Pg C/yr, respectively, and −0.02, 0.117, 0.013, −0.003 Pg C/yr, respectively, in Mexico. The mean net carbon flux for Latin America and the Caribbean was 0.645 Pg C/yr, and 0.126 Pg C/yr for Mexico. The terrestrial sinks in Latin America and the Caribbean are dominated by the forest, agricultural, grass and shrub regions, as well as the Andes mountain range and the net surface-atmosphere fluxes including fossil fuel are dominant in regions around large cities in Mexico, Brazil, Chile, and areas undergoing deforestation along the Amazon River. The results confirm that forest fres are an important source of CO2 in Latin America and the Caribbean. In addition, we can confirm that policies encouraging the use of ethanol in light vehicles in Brazil have helped to decrease carbon emissions from fossil fuel, and assume the effects of the Proárbol program on carbon sinks from the biosphere and from fire emissions sources in Mexico. Based on this analysis, we are confident that the CT system will play a major role in Latin America and the Caribbean as a scientific tool to understand the uptake and release of CO2 from terrestrial ecosystems, fossil fuel use and the oceans, and for long-term monitoring of atmospheric CO2 concentrations. 相似文献
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India is endowed with more than 3000 million tons of bauxite resources. Out of total India reserves, about 70% reserves are concentrated in Eastern Ghats (Odisha and Andhra Pradesh) region. Majority of the Eastern Ghat bauxite deposits are located at high altitude (high level type) and have been developed on khondalite and charnockite group of rocks with different geomorphological conditions. These are formed at an elevation of about 900- 1400 meter above mean sea level (msl). The physico-mechanical and technological properties of these bauxite vary widely depending upon the parent rock composition, mode of origin, geomorphological position, duration and age of bauxite formation. In the Bayer process the most important parameter that decides the economic importance is the quality of bauxite which again decides the digestion parameters for alumina extraction. Jawaharlal Nehru Aluminium Research Development and Design Centre (JNARRDC) is in process of evaluating the bauxite and laterite deposits of India for its suitability for commercial applications. The present paper highlights the geological and geomorphological features of Eastern Ghats bauxite deposits and their technological characteristics. These studies are required to evaluate the bauxite in terms of their suitability for metallurgical and non metallurgical applications. 相似文献