Detrital zircon U–Pb ages of Silurian–Devonian sediments from NW Svalbard: a fragment of Avalonia and Laurentia?
Detrital zircon U–Pb ages of Silurian–Devonian sediments from NW Svalbard: a fragment of Avalonia and Laurentia?
复制标题
斯瓦尔巴群岛西北部志留纪-泥盆纪沉积物的碎屑锆石 U-Pb 年龄：阿瓦隆尼亚和劳伦西亚的碎片？
DOI：
10.1144/0016-76492010-062
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发表时间：
2010
影响因子：
2.7
通讯作者：
D. Frei
中科院分区：
文献类型：
--
作者：
C. Pettersson;V. Pease;D. Frei
摘要：采用 U-Pb 激光烧蚀电感耦合等离子体质谱法对斯瓦尔巴群岛西北部志留纪-泥盆纪碎屑岩中的碎屑锆石群进行了分析，以研究斯瓦尔巴群岛西北地体的前加里东期物源。由此产生的年龄谱的变化表明，源头发生了重大转变，从志留纪末期的劳伦-阿瓦隆缝合带到晚志留世-早泥盆世西北地体的局部变沉积基底，以及从洛克科阶到格伦维尔-斯韦科诺威阶源头。这些数据，加上来自斯瓦尔巴群岛、东格陵兰岛和阿瓦隆尼亚的结构、附加地质年代和变质数据，支持斯瓦尔巴群岛的合并是沿左旋走滑断层长距离迁移的结果。斯瓦尔巴群岛最终合并的统一模型与斯瓦尔巴群岛的地层和构造热历史一致，涉及最初增生到劳伦斯边缘的格兰屏造山带和阿瓦隆地壳的碎片，随后在斯堪的纳变形期间沿着左旋走滑断层向北输送。补充材料：样品制备程序、激光烧蚀 ICP-MS 分析方法和数据表可在 http://www.geolsoc.org.uk/SUP18421 上获取。
Abstract: Detrital zircon populations from Silurian–Devonian clastic rocks of NW Svalbard were analysed by U–Pb laser ablation inductively coupled plasma mass spectrometry to investigate the pre-Caledonian provenance of Svalbard's Northwestern Terrane. Changes in the resulting age spectra suggest a major shift in sources from the Laurentian–Avalonian suture in the latest Silurian to the local metasedimentary basement of the Northwestern Terrane in the Late Silurian–Early Devonian, and in the Lochkovian to Grenvillian–Sveconorwegian sources. These data, together with structural, additional geochronological and metamorphic data from Svalbard, East Greenland and Avalonia, support the amalgamation of Svalbard as the result of long-distance transport along sinistral strike-slip faults. A unifying model for the final amalgamation of Svalbard, consistent with the stratigraphical and tectonothermal history of Svalbard, involves fragments from the Grampian orogen and Avalonian crust originally accreted to the Laurentian margin being subsequently transported northward along sinistral strike-slip faults during Scandian deformation. Supplementary material: The sample preparation procedures, laser ablation ICP-MS analytical methods, and data table are available at http://www.geolsoc.org.uk/SUP18421.