助手标题
全文文献 工具书 数字 学术定义 翻译助手 学术趋势 更多
查询帮助
意见反馈
共[3]页 共[43]条 当前为第1条到20条
 

相关语句
detrital zircons
Age of Detrital Zircons from Sandstones of the Mesozoic Flysch Formation in the South Anyui Suture Zone (Western Chukotka)
      
This work presents first data on age estimates of detrital zircons from Upper Mesozoic terrigenous sequences of the South Anyui suture zone obtained by the fission-track method.
      
The fission-track dating showed that sandstones from the flysch sections contain detrital zircons of two different-age populations.
      
The U-Pb dating of zircons from the metadacites and detrital zircons from the metagraywackes of the Kalikorva structure yielded similar ages of 2785 ± 13 and 2766 ± 21 Ma, respectively.
      
This paper presents the results of structural, lithologic, and geochronological (K-Ar, Rb-Sr) studies of the Carnian terrigenous rocks in the sedimentary cover of the Chukchi microcontinent and U-Pb dating of detrital zircons.
      
The detrital zircons comprise several populations with predominance of the varieties derived from igneous rocks.
      
As a result, the oldest 207Pb/206Pb ages of 3151 ± 4.6 and 3329 ± 16 Ma are first determined for detrital zircons from northern and eastern Karelia.
      
The oldest detrital zircons from siliciclastic metasediments determine the stabilization time of Archean continental nuclei in East Fennoscandia.
      
The volcanic succession was a source for some overlying sedimentary rock units, as indicated by the presence of detrital zircons dated at 2,777-2,771?Ma.
      
A maximum age of 2133±4?Ma for Tarkwaian sedimentation is provided by 71 of 111 concordant SHRIMP II U-Pb dates from detrital zircons in Tarkwaian clastic rocks from Damang and Bippo Bin, northeast of Tarkwa.
      
Age and origin of detrital zircons from the pre-Permian basements of the Bohemian Massif and the Alps
      
U-Pb systematics of detrital zircons from some unmetamorphosed to slightly metamorphosed sediments of Central Europe
      
Conventional and ion-microprobe U-Pb dating of detrital zircons of the Tentudía Group (Serie Negra, SW Spain): implications for
      
The presence of about 20% of Pan-African detrital zircons ranging from about 700 to 550 Ma indicates the derivation from Gondwana.
      
The detrital zircons have 207Pb/206Pb ages between 1367 and 1939?Ma, with frequency maxima in the range 1.85 to 1.70?Ga and 1.60 to 1.50?Ga.
      
SHRIMP U-Pb ages of detrital zircons from a paragneiss sample yield a maximum age of 2043?Ma, with no evidence of an Archean Yilgarn signature.
      
Younger detrital zircons with 1150-1450?Ma ages, however, indicate an additional source that had undergone early Grenvillian igneous or metamorphic event(s) and also places a maximum age constraint upon deposition.
      
The age spectra for inherited zircons from the granites have been compared with those of detrital zircons from the enclosing low- and high-grade metasediments.
      
In broad terms, both for detrital zircons in all four sediments and for inherited zircons in three of the four granites, the dominant ages are early Paleozoic and Late Precambrian, with sporadic older Precambrian ages extending up to 3.5?Ga.
      
The ages of the youngest detrital zircons from the low-grade Lockhart and Talgarno terranes limit the time of sedimentation to ca.
      
 

首页上一页123下一页尾页 

 
CNKI主页设CNKI翻译助手为主页 | 收藏CNKI翻译助手 | 广告服务 | 英文学术搜索
版权图标  2008 CNKI-中国知网
京ICP证040431号 互联网出版许可证 新出网证(京)字008号
北京市公安局海淀分局 备案号:110 1081725
版权图标 2008中国知网(cnki) 中国学术期刊(光盘版)电子杂志社