检索结果-南通市图书馆

Ages, Trace Elements and Hf-Isotopic Compositions of Zircons from Claystones around the Permian-Triassic Boundary in the Zunyi Section, South China: Implications for Nature and Tectonic Setting of the Volcanism

引用

Journal of Earth Science 2015年第6期26卷 872-882页

作者： Qiuling Gao Zhong-Qiang Chen Ning Zhang William L.Griffin Wenchen Xia Guoqing Wang Tengfei Jiang Xuefei Xia Suzanne Y.O'reilly Exploration & Development Research Institute Zhongyuan Oilfield Company School of Earth Sciences China University of Geosciences Australian Research Council Centre of Excellence for Core to Crust Fluid Systems and GEMOC National Key Centre Department of Earth and Planetary Science Macquarie University State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences Shandong Lunan Institute of Geo-Engineering Exploration Jianghan Oilfield Company

A growing body of evidence shows that volcanism near the Permian-Triassic boundary（PTB） may be crucial in triggering the Permian–Triassic（P–Tr） mass extinction. Thus, the ash beds near the PTB in South China may carry information on this event. Three volcanic ash layers, altered to clay, outcropped in the PTB beds in Zunyi Section, Guizhou Province, Southwest China. The U-Pb ages, trace elements, and Hf-isotope compositions of zircon grains from these three ash beds were analyzed using LA-ICPMS and LA-MC-ICPMS. The zircons are mainly magmatic in origin（241-279 Ma） except for two inherited/xenocrystic zircons（939 and 2 325 Ma）. The ages of these magmatic zircons indicate three episodes of magmatism which occurred around the MiddleLate Permian boundary（-261.5 Ma, MLPB）, the Wuchiapingian-Changhsingian boundary（-254.5 Ma, WCB）, and the PTB（-250.5 Ma）, respectively. The first two episodes of magmatism near the MLPB and WCB may be attributed to magmatic inheritance or re-deposition. All magmatic zircons share similar trace-element and Hf-isotope compositions. They have Y, Hf, Th and U contents and Nb/Ta ratios are typical of zircons from silicic calc-alkaline magmas. These zircons also exhibit enriched Hf-isotope compositions with _（εHf）（t） values of-11.4 to ＋0.2, which suggests that the three magmatic episodes involved melting of the continental crust. The more enriched Hf-isotope composition （_（εHf）（t）=-11.4--4.8） of Bed ZY13（-250.5 Ma） implies more input of ancient crustal material in the magma. Integration of the Hf-isotope and trace-element compositions of magmatic zircons suggest that these three episodes of magmatism may take place along the convergent continent margin in or near southwestern South China as a result of the closure of the Palaeo-Tethys Ocean.

关键词： Permian-Triassic boundary zircon trace elements Hf isotope silicic volcanism,convergent continental margin South China.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

爱上制作

引用

作者： (美)O'reilly

来源：南通市图书馆图书评论

学校读者我要写书评

暂无评论

爱上制作

引用

作者： (美)O'reilly

来源：南通市图书馆图书评论

学校读者我要写书评

暂无评论

镜子背后

引用

疯狂英语（初中天地） 2007年第3期 29-31页

作者： Laura reilly Darren

当我还是一个小女孩的时候,我们家住在纽约市里,和外公外婆家只相隔一个街区。外公每天晚上都会出去散步锻炼身体,有时我也会跟着他去。一天晚上,我和外公像往常一样去散步,我问起他小时候的生活是怎样的。他告诉我,那时候没有抽水马桶... 详细信息

当我还是一个小女孩的时候,我们家住在纽约市里,和外公外婆家只相隔一个街区。外公每天晚上都会出去散步锻炼身体,有时我也会跟着他去。一天晚上,我和外公像往常一样去散步,我问起他小时候的生活是怎样的。他告诉我,那时候没有抽水马桶,人们要到户外上厕所;

关键词：孤儿院

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Grenvillian orogeny in the Southern Cathaysia Block:Constraints from U-Pb ages and Lu-Hf isotopes in zircon from metamorphic basement

引用

Chinese Science Bulletin 2008年第19期53卷 3037-3050页

作者： WANG LiJuan YU JinHai S.Y. O'reilly W.L. GRIFFIN SUN Tao WEI ZhenYang JIANG ShaoYong SHU LiangShu State Key Laboratory for Mineral Deposits Research Department of Earth Sciences Nanjing University Nanjing 210093 China GEMOC National Key Centre Department of Earth and Planetary Science Macquarie University Sydney NSW 2109 Australia

Metamorphic basement rocks in the Cathaysia Block are composed mainly of meta-sediments with different ages. New zircon U-Pb geochronological results from the meta-sedimentary rocks exposed in the Zengcheng and Hezi areas, southern Cathaysia Block, show that they consist dominantly of early Neoproterozoic (1.0―0.9 Ga) materials with minor Paleo- to Mesoproterozoic and late Neoproterozoic (0.8―0.6 Ga) components, suggesting that the detritus mostly come from a Grenvillian orogen. The youngest detrital zircon ages place a constraint on the deposition time of these sediments in Late Neoproterozoic. Zircon Hf isotopic compositions indicate that the Grenvillian zircons were derived from the reworking of Mesoproterozoic arc magmatic rocks and Paleoproterozoic continental crust, implying an arc-continent collisional setting. Single-peak age spectra and the presence of abundant euhedral Grenvillian zircons suggest that the sedimentary provenance is not far away from the sample location. Thus, the Grenvillian orogen probably preexisted along the southern margin of the Cathaysia Block, or very close to the south. Similarity in the ages of Grenvillian orogeny and the influence of the assembly of Gondwana in South China with India and East Antarctic are discussed, with suggestion that South China was more likely linked with the India-East Antarctica continents in Early Neoproterozoic rather than between western Laurentia and eastern Australia.

关键词：华夏古大陆格伦维尔期锆石同位素新元古代

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

爱上制作

引用

作者： (美)O'reilly

来源：南通市图书馆图书评论

学校读者我要写书评

暂无评论

爱上制作

引用

作者： (美)O'reilly

来源：南通市图书馆图书评论

学校读者我要写书评

暂无评论

Music Improves Energy Levels

引用

英语世界 2021年第4期40卷 127-128页

作者： John O'reilly Freddie Gay

Exercise and music Many runners and gym members feel that music makes exercise more enjoyable. However, they might not know that scientists have found that some kinds of music can improve people's energy by 15 per cent. This was discovered by Dr Costas Karageorghis at Brunel University's School of Sport and Education.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

爱上制作

引用

作者： (美)O'reilly

来源：南通市图书馆图书评论

学校读者我要写书评

暂无评论

爱上制作

引用

作者： (美)O'reilly

来源：南通市图书馆图书评论

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：