元古代
- 与 元古代 相关的网络例句 [注:此内容来源于网络,仅供参考]
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In the geological time scale, there are five eras , the archeozoic which means "beginning life", the Proterozoic which means " fore life"
在地质年代表中共划分为5个代,太古代的意思是"生命的开始"。元古代意即"生命之前"
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Usually the archeozoic and Proterozoic eras are grouped together and referred to as Precambrian in age. Precambrian rocks have been intensely deformed, metamorphosed and intruded, and are relatively barren of fossil s.
通常太古代和元古代被归在一起而称作前寒武纪,前寒武纪的岩石多遭受强烈变形、变质或被岩浆岩侵入,岩石中缺少化石。
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Usually the archeozoic and Proterozoic eras are grouped together and referred to as Precambrian in age. Precambrian rocks have been intensely deformed, metamorphosed and intrude d, and are relatively barren of fossils.
通常太古代和元古代被归在一起而称作前寒武纪,前寒武纪的岩石多遭受强烈变形、变质或被岩浆岩侵入,岩石中缺少化石。
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The Pb-Pb isochron of metamorphic argillite in Shuangqiaoshan Group is 1 490±68 Ma, while the Nd mode ages of Zhanggongshan Group, Shuangqiaoshan Group, Chenglang Group and Xiushui Group are 1.57 Ga, 1.89 Ga, 1.77 Ga, 1.60 Ga,respectively, less than 1.6-1.9 Ga, which suggest that they formed in Middle Proterozoic Subera.
研究结果还显示,双桥山群变质泥质岩的Pb-Pb等时线年龄为(1 490±68)Ma,而障公山群、双桥山群、程浪群和修水群的钕模式年龄分别为1.57 Ga、1.89Ga、1.77Ga和1.60 Ga,均分布在1.5~1.9 Ga之间,表明这些地层的形成年龄应小于1.9 Ga,是中—晚元古代的产物,同时表明扬子古陆南缘存在古元古代的基底。
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By the single zircon U Pb dating method, the quartz syenite porphyny yielded an age of concordance (1 731±29)Ma, and the aegirine augite syenite and syenogebbro are dated upper cocordi...
应用单锆石U Pb法测定年龄,石英正长斑岩谐和年龄为( 1731± 2 9)Ma ,霓辉正长岩、正长辉长岩上交点年龄分别为( 1644± 14)Ma、( 1750± 65)Ma.1650~ 170 0Ma是碱性岩浆活动热构造事件的标志,石英正长斑岩被中元古代晚期的高山河组不整合覆盖,故以 1650~ 170 0Ma作为熊耳群的上限。1650~ 170 0Ma热构造事件是华北地块重大地质事件,有可能是进一步划分中元古代重要的年龄界限。
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These results indicate that both the second type leucosome in the biotite gneisses and the first type leucosome were produced synchronously in the Paleoproterozoic granulite-facies metamorphism, and that both the melt-derived and the metamorphic Paleoproterozoic zircons suffered significant lead-loss in the Triaasic, suggesting that both felsic granulite and biotite gneisses be responses to the Triassic deep subduction event.
这表明,第二类浅色体和第一类浅色体都是古元古代麻粒岩相变质作用同期深熔产物。古元古代熔体结晶和变质结晶锆石在三迭纪发生了严重的放射性成因铅丢失,可反映长英质麻粒岩和黑云母片麻岩都响应了三迭纪深俯冲事件。
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The basal continental crust of Tarim-Tianshan area in Xinjiang consists of the continental nucleus, which is composed of grey gneisses, greenstones, and potass granites similar to charnockites, and its accretionary belts mainly of the early Proterozoic and partly the Middle Proterozoic.
塔里木-天山地区基底陆壳由太古宙灰色片麻岩、绿岩和可能是紫苏花岗岩的含钾花岗岩类组成的陆核及其古元古代和少量中元古代增生带组成。
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In the northwestern part of North China Craton, there is a series of the Early Proterozoic thrust structure s.
华北克拉通西北部发育一系列早元古代的逆冲构造,它们在岩石组成、构造样式、产状、运动方式和时代等方面的特征具有明显的一致性,表明该地区在早元古代经历了一次强烈的造山作用。
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Several main results on the evolutions of the life and environment on early earth are summarized as follows:(1) the oxygenation of surface environment didn''t cease until a stable stage for 0.4Ga appeared after 1.6Ga;(2) compared to the isotopic compositions of kerogens and coexisted carbonates, the differences between two can effectively carrier the signals from local environments and bio-assemblages;(3) multiple isotopic relationships between kerogens and individual alkanes in Proterozoic samples were observed, which would depend on the specific biogeochemical processes;(4) repeated biogeochemical changes were observed accompanying Neoproerozoic glaciations, which suggesting that environmental rather than evolutionary forces were driving the biogeochemical changes;(5) the bio-radiations after Neoproterozoic glaciations were definitely suggested by molecular and isotopic data to be at the early Cambrian and after the middle of Doushantuo deposition with different triggers for them.
研究获得以下重要认识:(1)古元古代地表环境的氧化可能一直持续到中元古代早期(约1.6Ga),而在此之后的4亿年里则保持相对稳定;(2)相对于传统的干酪根和碳酸盐的碳同位素组成,二者之差则能更好反映区域环境的演化特征;(3)在元古代干酪根与单体烷烃类之间存在多种碳同位素组成关系;而其与不同的生物地球化学过程有关;(4)全球海洋生物地球化学特征随新元古代多次冰期出现循环波动,这显然为环境因子的驱动;(5)在新元古代大冰期之后,分子与同位素数据显示地球生命在陡山沱中后期和早前寒武纪出现两次大辐射,然而两次生命辐射的本质却是不同的。
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The data show the following ages: 1894±17 Ma and 1847±59 Ma for garnet pyroxenite of the Tiantangshan Group complex, indicating a Paleoproterozoic age; 1462±28 Ma for the metabasic volcanic rocks of the Yunkai Group complex, indicating the presence of fragments of the Meso- and Neoproterozoic oceanic crust in the Yunkai area; 906±24 Ma for the granitic gneiss intrusion is, which should be the product of the global Grenville collisional orogeny occurring around 1000 Ma BP. In addition, an inherited detrital zircon age of 2702±13 Ma was also obtained, which is the oldest age in the Yunkai area and even in Cathaysia, proving the presence of Neoarchean continental crustal material in Cathaysia.
获得天堂山岩群石榴辉石岩的形成年龄为1894Ma±17Ma和1847Ma±59Ma,表明其时代为古元古代;云开岩群洋中脊型变质基性火山岩的喷发年龄为1462Ma±28Ma,证明该地区存在中元古代的古洋壳残片;获得花岗质片麻岩的侵入年龄为906Ma±24Ma,应为1000Ma前后发生的全球性Grenville期造山作用的产物,并获得2702Ma±13Ma的继承碎屑锆石年龄,这是云开地区乃至华夏古陆目前获得的最古老年龄,证明华夏古陆曾存在新太古代陆壳物质。
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The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.
采用不同浓度K2CrO4(0,0.4,0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗,测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。
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By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.
通过分析数学形态学在图像中的理论基础,研究二值图像的形态分析算法,探讨最小结构元素的两种基本形态:膨胀和腐蚀;分析了数学形态学复杂算法的基本原理,把数学形态学的部分并行处理理念引入到家实际应用中。
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Have a good policy environment, real estate, secondary and tertiary markets can develop more rapidly and improved.
有一个良好的政策环境,房地产,二级和三级市场的发展更加迅速改善。