A Rheic cause for the Acadian deformation in Europe
A Rheic cause for the Acadian deformation in Europe
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欧洲阿卡迪亚变形的瑞克原因
DOI：
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发表时间：
2007
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：
N. Woodcock;N. J. Soper;R. Strachan
欧洲西北部的中泥盆世变形通常被解释为志留纪Iapetus洋闭合的最终事件。这一观点受到了早期泥盆纪跨组装的白俄罗斯大陆部分的跨张事件的质疑。相反，南大洋的缩短必须由新的“南方的推力”驱动，包括莱茵洋的俯冲，以及另一个冈瓦纳大陆碎片的平板俯冲或撞击。这两种假说的一个问题是，在位于拉吉乌斯带和里克缝合线之间的莱茵海西带段，缺乏拉吉乌斯变形，甚至缺乏相关的不整合面。探讨了该Rhenohercynian段仅在最后的西印度和/或华力西构造期间与西印度带和米德兰微克拉通并置的可能性。如果是这样的话，一条主要的岩石圈缝合线就埋藏在华力西前缘的南部，沿着布里斯托海峡断裂带，而失踪的阿卡德人的岩石圈缝合线现在一定位于造山带沿着的其他地方。最后提出了它们与西北伊比利亚外来岩有关的观点。在任何情况下，在欧洲发生的古罗马事件都应该被正确地视为原华力西运动，而不是加里东运动晚期。
The Acadian (mid-Devonian) deformation in NW Europe has typically been interpreted as the culminating event of the Silurian closure of the Iapetus Ocean. This view has been challenged by the recognition of an intervening early Devonian transtensional event across part of the assembled Laurussian continent. Instead, the Acadian shortening must be driven by a renewed ‘push from the south’, involving subduction of the Rheic Ocean, and either flat-slab subduction or impingement of another Gondwana-derived continental fragment. A problem with either hypothesis is the lack of Acadian deformation or even correlative unconformity in the segment of the Rhenohercynian Zone between the Acadian belt and the Rheic suture. The possibility is explored that this Rhenohercynian segment was juxtaposed with the Acadian belt and the Midland Microcraton only during latest Acadian and/or Variscan tectonics. If so, a major lithospheric suture lies buried just south of the Variscan Front, along the Bristol Channel Fault Zone, and the missing Acadian terranes must now lie elsewhere along the orogen. A case is made that they are related to the allochthonous terranes of NW Iberia. In any case, the Acadian event in Europe should properly be regarded as proto-Variscan rather than late Caledonian.