SHRIMP U-Pb zircon dating for Qiashikansayi granodio-rite, the Northern Altyn Tagh Mountains and its

来源 :Chinese Science Bulletin | 被引量 : 0次 | 上传用户:xujuenrong
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The Qiashikansayi granodiorite is foliated resulting in a granodioritic gneiss. Its geochemical features, such as alumina saturation index(A/CNK) of 0.81-0.99, Na2O/K2O values>1, TiO2 contents <1.0%, LREE enrichment with high fractionation factors, weakly negative or no Eu anomalies, and significant Ba and Ti negative anomalies, suggest that it is similar to a typical island arc pluton. The trace elements of the Qiashikansayi granodiorite are plotted in the island arc field in the tectonic setting discrimination diagrams as well. Cathodoluminescence images demonstrated that the zircons have clear rhythmic crystallized zoning, without any remnant core and new crystallized rim, suggesting the zircons be magmatic ones. Their U and Th contents vary in the range of 574-870 μg/g, and 279-556μg/g respectively, with the Th/U ratio in the range of 0.52-0.68. SHRIMP zircon U-Pb dating yielded the 481.5±5.3 Ma age for the intrusion of the granodiorite, which is coeval with the island arc volcanic rocks in the no The Qiashikansayi granodiorite is foliated resulting in a granodioritic gneiss. Its geochemical features such as alumina saturation index (A / CNK) of 0.81-0.99, Na2O / K2O values> 1, TiO2 contents <1.0% weakly negative or no Eu anomalies, and significant Ba and Ti negative anomalies, suggest that it is similar to a typical island arc pluton. The trace elements of the Qiashikansayi granodiorite are plotted in the island arc field in the tectonic setting discrimination diagrams as well. Cathodoluminescence images of that zircons have clear rhythmic crystallized zoning, without any remnant core and new crystallized rim, suggesting the zircons be magmatic ones. Their U and Th contents vary in the range of 574-870 μg / g, and 279-556 μg / g respectively, with the Th / U ratio in the range of 0.52-0.68. SHRIMP zircon U-Pb dating yielded the 481.5 ± 5.3 Ma age for the intrusion of the granodiorite, which is coeval with the island arc volca nic rocks in the no
其他文献
Paleomagnetic and rock magnetic studies on samples of 18 sites from the Creta- ceous marine sedimentary rocks in the Tongyouluke section, Akto County, southwes
The 1995 Northern Niigata Earthquake (M 6.0) occurred at a shallow depth in the Niigata seismic gap. The anomaly areas in temperature, electrical conductivity a
进入大学阶段,非英语专业的学生既需要在短短的两年左右时间内迅速将词汇量从1800提高到4500,又要掌握2000个积极词汇的深度知识,能够在认知的基础上,熟练运用这些词汇。而课
我院自1987年8月至今,共收治食管贲门癌性狭窄258例,其中223例行内镜下介入治疗,部分病例结合小剂量放疗、化疗,20例单纯化疗、15例单纯放疗作为对照.现将相关治疗疗效及不良反应等作一比较,以期找出较为合理的治疗方法.
随着社会经济的快速发展,人才市场上竞争越来越激烈。中职学生面临着越来越重要的就业压力。因此,其只有提升自身的专业技能,提高自身的人文素质才能够保证未来的就业。所以,
随着时代的发展,人们对于高职学校的看法也在不断改变。国家对于高职院校的扶持使得高职院校在各方面都有了发展。但是随之而来的是大量高职院校的出现,使得学生家长在为孩子
Continent-continent collision is the most important driving mechanism for the occurrence of various geological processes in the continental lithosphere. How to
随着社会发展需要,新时代企业需要具有高度制度道德的职工,职工的工匠精神成为社会热门议题。怎样通过工匠精神的培养树立学生的职业素养,成为目前高职院校学生培养的新要求,
针对目前受激布里渊散射(SBS)阈值研究主要针对单模光纤,而对多模光纤研究较少的现状,理论分析和计算了多模光纤SBS阈值特性。结果表明:对于多模光纤,由于其多个模式的布里渊
语言是文化的一部分,是文化的主要载体,语言背后反映的都是一国的文化。由于中西方国家的历史背景、宗教信仰、风俗习惯等有所差异,使得英汉互译有一定的难度。本文旨在探讨