U–Pb zircon constraints on obduction initiation of the Unst Ophiolite: an oceanic core complex in the Scottish Caledonides?
U–Pb zircon constraints on obduction initiation of the Unst Ophiolite: an oceanic core complex in the Scottish Caledonides?
复制标题
U-Pb 锆石对 Unst 蛇绿岩仰冲起始的限制：苏格兰喀里多尼德山脉的海洋核心杂岩？
DOI：
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发表时间：
2015
影响因子：
2.7
通讯作者：
R. Strachan
中科院分区：
文献类型：
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作者：
Q. Crowley;R. Strachan
Unst蛇绿岩是苏格兰加里多尼德地区早奥陶世蛇绿岩链中暴露最好的，被广泛认为形成于伊阿普图斯洋内的超俯冲带。对席状岩墙的重新解释表明，它是作为一个海洋核心杂岩形成的，推测是在俯冲到劳伦斯边缘之前的俯冲回滚过程中形成的。变质岩底发育的新U-Pb锆石年龄为484 ± 4 Ma，这为俯冲作用的时间设定了下限，随后在格兰宾造山事件中发生了区域尺度的地壳增厚和巴罗纪变质作用。补充材料：分析方法、具有代表性的锆石颗粒的化学发光图像和LA-ICPMS U-Th-Pb锆石数据表可在www.geoloc.org.uk/SUP18814上查阅。
The Unst Ophiolite is the best exposed of a chain of early Ordovician ophiolites in the Scottish Caledonides and is widely regarded as having formed in a supra-subduction zone setting within the Iapetus Ocean. Reinterpretation of sheeted dykes suggests that it formed as an oceanic core complex, presumably during subduction roll-back immediately prior to obduction onto the Laurentian margin. A new U–Pb zircon age of 484 ± 4 Ma for development of the metamorphic sole places a lower limit on the timing of obduction, which was subsequently followed by regional-scale crustal thickening and Barrovian metamorphism during the Grampian orogenic event. Supplementary material: Analytical methods, CL images of representative zircon grains and an LA-ICP-MS U–Th–Pb zircon data table are available at www.geolsoc.org.uk/SUP18814.
影响因子：
5.3
作者：
Morris, A.;Gee, J. S.;Searle, R. C.
通讯作者：
Searle, R. C.