The Souter Head sub-volcanic complex (Aberdeenshire, Scotland) intruded the high-grade metamorphic core of the Grampian Orogen at 469.1 ± 0.6 Ma (uranium-238–lead-206 (238U–206Pb) zircon). It follows closely peak metamorphism and deformation in the Grampian Terrane and tightly constrains the end of the Grampian Event of the Caledonian Orogeny. Temporally coincident U–Pb and argon/argon (40Ar/39Ar) data show the complex cooled quickly with temperatures decreasing from ca.800 °C to less than 200 °C within 1 Ma. Younger rhenium–osmium (Re–Os) ages are due to post-emplacement alteration of molybdenite to powellite. The U–Pb and Ar/Ar data combined with existing geochronological data show that D2/D3 deformation, peak metamorphism (Barrovian and Buchan style) and basic magmatism in NE Scotland were synchronous at ca.470 Ma and are associated with rapid uplift (5–10 km Ma−1) of the orogen, which, by ca.469 Ma, had removed the cover to the metamorphic pile. Rapid uplift resulted in decompressional melting and the generation of mafic and felsic magmatism. Shallow slab break-off (50–100 km) is invoked to explain the synchroneity of these events. This interpretation implies that peak metamorphism and D2/D3 ductile deformation were associated with extension. Similarities in the nature and timing of orogenic events in Connemara, western Ireland, with NE Scotland suggest that shallow slab break-off occurred in both localities.

中文翻译：

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苏特海德复合体的多时计测年：快速挖掘终止了加里东造山运动的格兰屏事件

Souter Head 次火山杂岩（苏格兰阿伯丁郡）在 469.1 ± 0.6 Ma（铀-238-铅-206（238U–206铅）锆石）。它紧随格兰屏地体的变质作用和变形峰值，并紧紧地限制了加里东造山运动的格兰屏事件的结束。时间重合的 U-Pb 和氩/氩 (40氩气/39Ar) 数据显示复合物迅速冷却，温度从约0.800 °C 至低于 200 °C，在 1 Ma 内。较年轻的铼-锇 (Re-Os) 年龄是由于辉钼矿侵位后转变为白钨矿。U-Pb 和 Ar/Ar 数据结合现有的年代学数据表明，苏格兰东北部的 D2/D3 变形、峰值变质作用（巴罗和布坎式）和基本岩浆作用在约470 Ma 并与快速隆起有关（5-10 km Ma-1) 的造山带，其中，通过约469 Ma，已拆除了变质堆的覆盖物。快速隆升导致减压熔融和镁铁质和长英质岩浆作用的产生。浅板断裂（50-100 km）被用来解释这些事件的同步性。这种解释意味着峰值变质作用和 D2/D3 韧性变形与伸展有关。爱尔兰西部康尼马拉与苏格兰东北部造山活动的性质和时间相似，表明这两个地区都发生了浅板断裂。