共查询到18条相似文献，搜索用时 156 毫秒
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希腊Samos岛西部晚中新世盐碱湖中硬硼钙石和钠硼解石的产状 总被引：1，自引：0，他引：1
<正> 0 引言工业硼酸盐矿床主要是钠硼酸盐、钠-钙硼酸盐和钙硼酸盐,如硬硼钙石、硼砂(原硼砂)、钠硼解石、贫水硼砂和板硼钙石。另外还有100多种硼酸盐矿物,但含量较低,其中最常见的有:图硼锶石、斜硼钠钙石、三方硼砂、砷硼镁钙石和水硼锶石。所有硼酸生产国(除前苏联外)的硼酸盐矿床都是表生沉积形成的,包括低—中等水溶性硼酸盐。相反,罕见的内生镁硼酸盐——硼镁石是前苏联的主要硼酸盐资源。表生类型的硼酸盐和硼酸的富集赋存在以下的环境中:(1)火山喷气和热泉;(2)海洋 相似文献
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柴达木盆地小柴旦湖硼酸盐的形成 总被引：6，自引：0，他引：6
本文探讨了小柴旦湖第四纪沉积物中的钠硼解石和柱硼镁石的特征和成因,并进行了盐湖卤水的模拟实验,认为硼酸盐矿物在卤水浓缩的早期到晚期均可形成。 相似文献
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<正>阿根廷是南美一个重要的硼酸盐资源地。 在南美,沿着阿根廷、玻利维亚、智利和秘鲁四国的公共边界,延伸885km长的安第斯山脉构造火山带上,由于当地的构造-火山活动及干旱气候,为硼酸盐矿床的沉积提供了条件,形成了大约40多个硼酸盐矿床。有靠近火山口附近的硼钠钙石和硼砂矿体,也有在盆地中的硼钠钙石、硼砂和板硼钙石矿层,储量达几百万吨,B2O3平均达到20％左右。其中以阿根廷北部的萨尔塔省的廷卡拉尤矿最为有名,该矿是世界上最有名的硼砂矿床之一。阿根廷北部也是该矿带上唯一有意义的硼酸盐生产区,阿根廷的大多数硼酸盐矿石都是产自廷卡拉尤矿。 相似文献
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西藏聂尔错镁硼矿地质特征及成矿机制 总被引：1，自引：0，他引：1
聂尔错镁硼矿为新近发现的一处镁硼矿床。本文通过对其区域地质资料、矿床地质特征研究,并与国内外矿床进行对比,分析了成矿物质来源和成矿机制,总结了成矿模式。聂尔错镁硼矿床赋存于中上全新统,有三个含矿层,中、上含矿层为主要可采矿层,下含矿层为次要含矿层;矿石类型包括粒状集合体库水硼镁石矿、含芒硝库水硼镁石矿、蜂窝状/块状柱硼镁石和混和类型矿石等4种,前两种为主要开采矿石,后两种为次要开采矿石。矿床对比研究表明,聂尔错镁硼矿床与其北部相邻的扎仓茶卡镁硼矿在有工业价值的硼矿物组合和形成矿床的地质环境等方面相同,属同类型矿床,但不同于国内外其它硼矿床。该矿床的成矿物质来源主要为新近纪火山岩。印度板块与亚洲版块碰撞,在靠近班公湖-怒江缝合带的聂尔错盐湖南部形成大面积富含B、Li、Mg、Na等成矿物质的新近纪火山岩,地热水及大气降水将大量成矿物质带入湖中,在干冷气候条件下,湖水浓缩成富含钠盐的饱和成矿溶液,并沉淀了库水硼镁石、柱硼镁石等,形成聂尔错镁硼矿床。 相似文献
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本文报道了青藏高原火山-沉积硼矿找矿的新成果,首次发现和确认在青藏高原存在富硼的火山-沉积二元结构的地层,其构造位置、岩石地层组合和时代与同一成矿带西部的安纳托利亚高原的大型火山-沉积硼矿床都一致,且地层的稀碱金属元素含量高正异常,并已发现有团块或条带状的钠硼解石和硼砂等硼酸盐矿物,局部硼含量达边界品位。说明雄巴盆地具备形成火山-沉积硼矿床的构造地质、岩石矿物和地球化学的先决条件,具有形成大型火山-沉积硼矿的潜力。该发现是我国突破大型火山-沉积硼矿的先导性成果,为在青藏高原找寻该类型硼矿床提供重要科学依据。 相似文献
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青海和西藏的某些天然硼酸盐矿物的硼同位素组成 总被引：4，自引：0，他引：4
硼同位素地球化学的研究越来越受到国内外学者的关注。本文对我国盐湖主要分布地区的青海、西藏的某些富硼盐湖中结晶析出的硼矿物进行了硼同位素分析。所有的硼酸盐矿物都经过了X射线和化学分析的验证。分析结果表明 ,采集的西藏地区的硼酸盐矿物的1 1 B 1 0 B值为 4.0 0 5 1～ 4.0 6 31,δ1 1 B值为 - 11.1‰～ +3.2‰ ;青海地区的硼酸盐矿物的1 1 B 1 0 B值为 3.930 7～ 4.0 42 0 ,δ1 1 B值为 - 2 9.5‰～ - 2 .0‰。这说明这些地区的硼酸盐矿物沉积均属于陆相成因。 相似文献
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辽东地区沉积变质硼矿床及硼同位素研究 总被引：2，自引：2，他引：2
辽东地区元古界硼矿床属于沉积变质硼矿。根据现代盐湖沉积 ,认为硼矿物沉积通常为硼砂 ,然后在区域变质作用过程中 ,硼砂矿物转变为硼镁矿物或硼铁矿等硼酸盐矿物 ,但辽东硼矿床中不同硼矿物的硼同位素有一定差别。电气石富10 B ,δ11B值较低或呈负值 ;而硼镁石与硼镁铁矿类矿物明显富集11B ,δ11B值较高 ,为 +2 3‰～ +17 4‰。根据水岩作用过程中硼同位素分馏特征的研究 ,11B与10 B比较有下列 4个特征 :( 1) 11B属于极不相容元素 ,优先进入水相 ,因此在变质残余矿物相中形成低的δ11B值 ;( 2 )在蚀变和交代变质反应中硅优先替代11B进入矿物晶格 ,因此在硅化交代中可以降低δ11B值 ,而脱硅反应中可以提高δ11B值 ;水化作用中 ,OH-带入11B ,使富水矿物具有较高的δ11B值 ;( 3)热水沉积及热液交代成因电气石均具有较低的δ11B值或者为负值 ;( 4)通过最近的研究表明 ,在热蒸馏过程中 ,硼同位素会发生明显的分馏 ,11B倾向于进入蒸汽相 ,而使残余相或后蒸馏相亏损11B ,形成较低的δ11B值。因此可以认为辽东地区元古界硼矿床属于热水沉积电气石岩在后期区域变质或热变质过程中分解出硼酸气水溶液交代镁碳酸盐形成硼镁石或硼镁铁矿矿物 ,而非蒸发沉积变质矿床。 相似文献
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大柴旦盐湖卤水演变及环境变化的矿物学记录 总被引：4，自引：0，他引：4
大柴旦盐湖因蕴藏固体和液体硼矿资源成为柴达木盆地诸多盐湖中最早被关注和开发的盐湖之一。然而,对其常年水体底部沉积剖面的相关研究工作却几乎没有开展。报道了该盐湖中央湖底硼矿层以上连续沉积剖面的加速器质谱计（AMS）^14C年代学和矿物学研究结果,首次揭示湖底硼矿层形成于约3600aBP之前,剖面的岩性与矿物组成标示了晚全新世以来该盐湖水化学演化的3个主要阶段,受降水量主控的入湖径流量决定了盐湖水位和卤水水化学的阶段性演化特征,以及各阶段中十年级和百年级的水化学变动。研究结果为探讨柴达木盆地北部晚全新世以来水文气候的演变历史提供了代理记录。 相似文献
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青藏高原盐湖硼酸盐矿物 总被引：10，自引：0，他引：10
西藏硼砂早就闻名中外。多年来有关单位对青藏高原盐湖进行调查研究的结果表明,本区盐类矿物的种类多、分布广、储量丰富,以硼酸盐尤为突出。现已发现十余种硼酸盐矿物,其中水碳硼石、章氏硼镁石和多水氯硼钙石是首次发现的新矿物。在昆仑山两侧还发现一种新类型盐湖——硫酸镁亚型硼酸盐盐湖,正在沉积各种水合硼酸镁盐。 我们在进行青藏高原盐卤硼酸盐研究中发现了含硼浓缩盐卤加水稀释成盐这一过程。这为水合硼酸镁盐的形成提供了新的实验解释。 相似文献
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Progress and Prospects of Salt Lake Research in China 总被引：3，自引：0，他引：3
ZHENG Mianping ZHANG Zhen KONG Weigang and LIN Yongjie ZHANG Yongsheng LIU Xifang NIE Zhen KONG Fanjing QI Wen Jia Qingxian PU Linzhong HOU Xianhu WANG Hailei 《《地质学报》英文版》2016,90(4):1195-1235
China has unique salt lake resources, and they are distributed in the east of Eurasian salt lake subzone of the Northern Hemisphere Salt Lake Zone, mainly concentrated in the regions with modern mean annual precipitation lower than 500 mm. This paper preliminarily reviews the progress made in salt lake research in China for the past 60 years. In the research of Paleoclimate and paleoenvironment from salt lake sediments, a series of salts have been proposed to be indicators of paleoclimate, and have been well accepted by scholars. The chloride-sulfate depositional regions of the west Qaidam and the east Tarim have been revealed to be the drought center of China since the Quaternary, and more than 6 spreading stages of arid climate(salt forming) have been identified. Five pan-lake periods with highstands have been proved to exist during the late Quaternary on the Tibetan Plateau. In mineral resource prospecting and theories of the forming of salt deposits: the atlas(1:2500000) of hydrochemical zoning of salt lakes on the Tibetan Plateau has been compiled for the first time, revealing the zonal distribution and transition from carbonate type to chloride type from south to north and presenting corresponding mineral assemblages for different type of salt lakes; several large continental salt deposits have been discovered and the theory of continental potash deposition has been developed, including the salt deposition in deep basins surrounded by high mountains, the mineral deposition from multistage evolution through chains of moderate or shallow lakes with multilevels, the origin of potassium rich brines in gravel layers, and the forming of potassium deposits through the inheriting from ancient salt deposits, thus establishing the framework of "Continental Potash Deposition Theory"; several new types of Mg-borate deposits have been discovered, including the ulexite and pinnoite bed in Da Qaidam Lake, Qinghai, the pinnoite and kurnakovite bed in Chagcam Caka, Tibet, the kurnakovite bed in Lake Nyer, and the corresponding model of borate deposition from the cooling and dissolution of boron rich brines was proposed based on principles of geology, physics and chemistry. The anti-floatation-cold crystallization method developed independently has improved the capacity of KCl production to 3 million tons per year for the Qarham, serving the famous brand of potash fertilizer products. One 1.2 million ton K-sulfate production line, the biggest in the world, has been built in Lop Nor, and K-sulfate of about 1.6 million tons was produced in 2015. Supported by the new technology, i.e. brine preparation in winter-cooling-solarization-isolation-lithium deposition from salt gradient solar pond" the highest lithium production base at Zabuye Lake(4421 m), Tibet, has been established, which is the first lithium production base in China that reaches the year production of 5000 tons of lithium carbonate. The concept of Salt lake agriculture(Salt land agriculture) has been established based on the mass growth of Dunaliella and other bacillus-algae and the occurrence of various halophytes in saltmarsh and salt saline-alkali lands, finding a new way to increase arable lands and develop related green industry in salt rich environments. Finally this paper presents some new thoughts for the further research and development on salt science, and the further progress in salt science and technology will facilitate the maturing of the interdisciplinary science "Salinology". 相似文献
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The Qarhan Salt Lake area is the Quaternary depocenter of the Qaidam Basin, and carries thick lacustrine sediments, as well as rich potassium and magnesium salt deposits. The abundant resources and thick sediments in this lake provide an ideal place for the study of biogas formation and preservation, salt lake evolution, and the uplift of the Tibetan Plateau. In this study, we attempt to construct a paleomagnetic and ~(230)Th age model and to obtain information on tectonic activity and salt lake evolution through detailed studies on a 1300-m-long drill core(15DZK01) from the northwestern margin of the Qarhan Salt Lake area(Dongling Lake). Based on gypsum ~(230)Th dating, the age of the uppermost clastic deposit was calculated to be around 0.052 Ma. The polarity sequence consist of 13 pairs of normal and reversed zones,which can be correlated with subchrons C2r.1r-C1n of the geomagnetic polarity timescale(GPTS 2012)(from ~2.070 Ma to ~0.052 Ma). Sedimentary characteristics indicate that Dongling Lake witnessed freshwater environment between ~ 2.070 Ma and 1.546 Ma. During this period, the sedimentary record reflects primarily lakeshore, shallow-water and swamp environments, representing favourable conditions for the formation of hydrocarbon source rocks. Between 1.546 Ma and ~ 0.052 Ma, the Dongling Lake was in sulphate deposition stage, which contrasts with the central Qarhan Salt Lake area, where this stage did not occur in the meantime. During this stage, Dongling Lake was in a shallow saltwater lake environment, but several periods of reduced salinity occurred during this stage. During the late Pleistocene at ~0.052 Ma, the Dongling Lake experienced uplift due to tectonic activity, and saltwater migrated through the Sanhu Fault to the central Qarhan Salt Lake area, resulting in the absence of halite deposition stage. The residual saline water was concentrated into magnesium-rich brine due to the lack of freshwater, and few potassium salt deposits occur in the Dongling Lake area. 相似文献
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柴达木盆地一里坪石膏~(230)Th定年及成盐期与第四纪冰期和构造运动的关系 总被引：1，自引：0，他引：1
本文采用多接收电感耦合等离子体质谱法(MC-ICP-MS),对柴达木盆地一里坪15YZK01钻孔中前336.2 m含石盐地层中的7个石膏样品进行230Th定年。依据年代-深度公式,获得S1-S4盐层的成盐年代分别为733.8~716.0 ka、581.9~573.8 ka、181.6~179.3 ka和158.0~154.2 ka;含芒硝粉砂地层的年代为171.6 ka。结合前人对一里坪表面盐壳的14C测年数据,证实一里坪表面盐层S5开始形成于末次冰期。15YZK01钻孔记录的成盐期与青藏高原第四纪冰期及构造运动存在一定的对应关系:石盐层S1对应于"昆黄运动"之后的望昆冰期,以及深海氧同位素第18阶段(MIS18);S2对应于大间冰期,但是该年代比较接近望昆冰期;S3和S4石盐层及含芒硝粉砂层对应于共和运动和倒数第二次冰期MIS6;S5石盐层开始形成的时代对应于末次冰期MIS2。同时,通过对柴达木盆地多个钻孔含盐地层的测年数据进行总结,证实中更新世以来青藏高原冰川活动与柴达木盆地盐类沉积存在着一定的对应关系。柴达木盆地西北部的成盐盆地中通常发于有倒数第二次冰期和末次冰期的石盐层;而盆地东南部的察尔汗盐湖区仅发现有末次冰期以来的石盐层。柴达木盆地成盐期受到青藏高原第四纪冰期和构造运动的影响,第四纪冰期中盐湖水源补给量的减少,是导致柴达木盆地成盐的重要驱动因素。 相似文献
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C. Helvacı 《Mineralium Deposita》1984,19(3):217-226
The Emet borate deposits were formed in two separate basins, possibly part of an interconnected lacustrine playa lake, in areas of volcanic activity, fed partly by thermal springs and partly by surface streams. The borates are interlayered with tuff, clay and marl. Limestone occurs above and below the borate lenses. Sediments in both basins are similar but borate minerals show different mineralogical and geochemical features in the two basins.The Emet borate deposits are the only deposits known to contain any of the minerals veatchite-A, tunellite, teruggite and cahnite. Principal minerals are colemanite, with minor ulexite, hydroboracite and meyerhofferite.Thermal springs associated with local volcanic activity are thought to be the source of the borates. The initial brines from which the borates crystallized are deduced to have been high in sulphite and sulphate, low in chloride, and hence it is assumed that the initial brines were fed at all times by abundant calcium and boron with minor amounts of arsenic, strontium and sulphur. Realgar, celestite and native sulphur are almost ubiquitous in borates and sediments, and appear to have formed at all stages during deposition and diagenesis.The early colemanite, meyerhofferite, ulexite and teruggite nodules were probably formed directly from brines penecontemporaneously within the unconsolidated sediments below the sediment/water interface, and continued to grow as the sediments were compacted. Later generations of colemanite occur in vugs, veins and as fibrous margins to colemanite nodules. Tunellite appears to have formed during diagenesis with enrichment of Sr in some places. Diagenetic alterations include the partial replacement of colemanite by veatchite-A, cahnite, hydroboracite and calcite. 相似文献
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柴达木盆地南缘祁漫塔格—鄂拉山地区斑岩-矽卡岩矿床地质 总被引：10，自引：3，他引：7
柴达木盆地南缘祁漫塔格-鄂拉山地区发育斑岩-矽卡岩型铜多金属矿床,成矿主元素为Cu、Mo、Pb、Zn,大部分矿床伴生Au、Ag。斑岩型和矽卡岩型矿（化）体共生于同一个矿区之中,是这类矿床的一个重要特点。与成矿有关的侵入体是印支期的中酸性小岩体,它们具有浅成_超浅成和高侵位等特点。斑岩-矽卡岩矿床的成岩年龄和成矿年龄一致,形成于中三叠世至晚三叠世。它们是东昆仑造山带晚碰撞造山阶段壳-幔作用（幔源岩浆底侵-岩浆混合）的产物,与东昆仑地区这一时期的矽卡岩型铁多金属矿床、热液脉状多金属矿床,以及造山型金矿床共同构成了一个矿床成矿系列。 相似文献
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