Structures related to orogenic “collapse” may provide an important template for reactivation during later rifting. In the proximal rifted margin offshore Norway, the tectono‐sedimentary template related to collapse of the Caledonian mountain belt became widely eroded but inherited metamorphic core complexes and detachment faults evolved further in Late Paleozoic and Earliest Mesozoic time and became associated with very significant crustal thinning. The earliest rifting mode was dominated by structures that mimic the Devonian post‐Caledonian template and comprised a suite of Late Paleozoic to Early Triassic metamorphic core complexes, detachment faults, and supradetachment basins. The deep structure indicates necking of brittle over remnant ductile crust, and we document how the main decoupling level utilized by the earliest rifting structures were cut by a suite of steeper, more deeply incising set of seaward‐ and landward‐dipping Triassic faults. The latter exploited deep shear zones related to the previous intracrustal necking, enabling changes in polarity over short distances. The change from a core complex mode of extension to one involving more deeply incising faults took place prior to deposition of the Late Triassic‐Early Jurassic interrift succession and pre‐dated the main phase of lithospheric‐scale necking associated with Jurassic‐Cretaceous extension. The latter phase of large‐magnitude faulting commenced with reactivation of seaward‐dipping, deeply incised faults inherited from early rifting as well as structures related to the phase of Devonian post‐orogenic transtension. The current study demonstrates that great structural complexity and significant magnitudes of extension may be present in proximal margins, in particular those developed along collapsed orogens.

中文翻译：

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塌陷造山带裂谷：挪威近海近海陆壳连续切开

与造山“塌陷”有关的结构可能为以后裂谷过程中的重新活化提供重要的模板。在挪威近海的裂谷边缘，与加里东山带塌陷有关的构造沉积模板被广泛侵蚀，但继承了变质岩心复合体，并且在古生代晚期和最早的中生代时期断层断裂进一步发展，并与地壳变薄有关。最早的裂谷模式以模仿泥盆纪后卡莱多期模板的结构为主，包括一套晚古生代至早三叠世变质岩心复合体，脱离断层和超脱离盆地。较深的结构表明在残留的延性硬皮上有脆性颈缩，并且我们记录了最早的裂谷构造所利用的主要去耦水平是如何通过一组陡峭，切深的海向和陆向三叠纪断层来削减的。后者利用了与先前壳内颈缩相关的深剪切带，从而可以在短距离内改变极性。从核心复杂的扩张模式转变为涉及更深层切割断层的扩张模式，是在晚三叠世—早侏罗世间断序列的沉积之前发生的，并且早于与侏罗纪—白垩纪扩张有关的岩石圈规模颈缩的主要阶段。大地震断层的后期始于向海倾角的重新激活，从早期裂谷继承的深切断层以及与泥盆纪造山后变张相有关的构造。