Age and composition of crystalline basement rocks on the Norwegian continental margin: offshore extension and continuity of the Caledonian–Appalachian orogenic belt
Age and composition of crystalline basement rocks on the Norwegian continental margin: offshore extension and continuity of the Caledonian–Appalachian orogenic belt
复制标题
挪威大陆边缘结晶基岩的年龄和成分：加里东-阿巴拉契亚造山带的近海延伸和连续性
DOI：
10.1144/0016-76492010-136
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发表时间：
2011
影响因子：
2.7
通讯作者：
J. Daly
中科院分区：
文献类型：
--
作者：
T. Slagstad;B. Davidsen;J. Daly
摘要：挪威大陆边缘22口井已钻穿下伏基底。本文收集了来自北海和挪威海9口井的U-Pb锆石、全岩地球化学、Sm-Nd和Rb-Sr同位素数据，研究了挪威加里东构造的海上延续，以及它们在整个加里东-阿巴拉契亚造山带的相关性。北海古生代岩浆活动可分为两类。较老组由460 Ma钙碱性花岗岩组成，同位素组成演化，与上异古统类似岩石相关。较年轻的组由430 Ma英安岩和421 Ma亮辉长岩组成，其同位素组成演化较少。在挪威海，437 Ma同位素演化的花岗质岩浆活动和447 Ma较多的幼闪长岩岩浆活动与上异古统Bindal和Smøla-Hitra岩基的岩浆活动相关。北海和挪威海的元沉积基底岩以晚古元古代和中元古代颗粒为主，与苏格兰、格陵兰和斯瓦尔巴群岛的卡利多尼德岩相似。新的数据，以及对该带其他地方的研究表明，类似的岩石可能存在于造山带的大部分地区。补充资料：U-Pb同位素数据可在http://www.geolsoc.org.uk/SUP18471上获得。
Abstract: Twenty-two wells on the Norwegian continental margin have penetrated underlying basement. We present U–Pb zircon, whole-rock geochemical, and Sm–Nd and Rb–Sr isotopic data from nine wells in the North Sea and Norwegian Sea with relevance to the offshore continuation of the Norwegian Caledonides, and their correlation throughout the Caledonian–Appalachian orogenic belt. Palaeozoic magmatism in the North Sea can be divided into two groups. The older group consists of 460 Ma calc-alkaline granites with evolved isotopic compositions, correlative with similar rocks in the Uppermost Allochthon. The younger group consists of a 430 Ma dacite and a 421 Ma leucogabbro, with less evolved isotopic compositions. In the Norwegian Sea, isotopically evolved granitic magmatism at 437 Ma and more juvenile dioritic magmatism at 447 Ma are correlative with magmatism in the Bindal and Smøla–Hitra Batholiths in the Uppermost Allochthon. Metasedimentary basement rocks from the North Sea and Norwegian Sea, dominated by Late Palaeoproterozoic and Mesoproterozoic grains, resemble rocks found in the Caledonides of Scotland, Greenland and Svalbard. The new data, along with studies elsewhere along the belt, suggest that similar rocks may exist along much of the orogen. Supplementary material: U–Pb isotopic data are available at http://www.geolsoc.org.uk/SUP18471.