Precise U–Pb zircon dating using the chemical abrasion – isotope dilution – thermal ionization mass spectrometry (CA-ID-TIMS) method constrains the age of the Central Sudetic Ophiolite (CSO) in the Variscan Belt of Europe. A felsic gabbro from the Ślęża Massif contains zircon xenocrysts dated at 404.8 ± 0.3 Ma and younger crystals dated at 402.6 ± 0.2 Ma that determine the final crystallization age of the gabbro. An identical age of 402.7 ± 0.3 Ma was determined for plagiogranite from the Nowa Ruda–Słupiec Massif, and plagiogranite from the Braszowice–Brzeźnica Massif yields a similar, but less reliable, age of > 401.2 Ma. The different massifs in the CSO are therefore considered as tectonically dismembered fragments of a single oceanic domain formed at c. 402.6–402.7 Ma (Early Devonian – Emsian). The magmatic activity recorded in the CSO was contemporaneous with the high-temperature/high-pressure metamorphism of granulites and peridotites in the Góry Sowie Massif, separating dismembered parts of the CSO. This suggests geodynamic coupling between the continental subduction recorded in the Góry Sowie and the oceanic spreading recorded in the CSO. Regional geological data indicate that the CSO was obducted before c. 383 Ma, less than 20 Ma after its formation at an oceanic spreading centre. The CSO is shown to be one of the oldest and first obducted among the Devonian ophiolites of the Variscan Belt. The CSO probably originated in an evolved back-arc basin in which the influence of subduction-related fluids and melts increased with time, from negligible during the formation of predominant mid-ocean-ridge-type magmatic rocks to strong at later stages, when rodingites, epidosites and other minor lithologies formed.

中文翻译：

---

中央 Sudetic 蛇绿岩（欧洲华力斯坎带）：精确的 U-Pb 锆石测年和大地构造意义

使用化学磨损 - 同位素稀释 - 热电离质谱 (CA-ID-TIMS) 方法进行的精确 U-Pb 锆石测年限制了欧洲华力斯坎带中央 Sudetic 蛇绿岩 (CSO) 的年龄。来自 Ślęża 地块的长英质辉长岩含有年龄为 404.8 ± 0.3 Ma 的锆石异晶和年龄为 402.6 ± 0.2 Ma 的较年轻晶体，这决定了辉长岩的最终结晶年龄。来自 Nowa Ruda-Słupiec 地块的斜花岗岩的年龄相同，为 402.7 ± 0.3 Ma，而来自 Braszowice-Brzeźnica 地块的斜花岗岩的年龄相似，但不太可靠，年龄 > 401.2 Ma。因此，CSO 中的不同地块被认为是形成于C。402.6–402.7 Ma（早泥盆纪 - Emsian）。CSO 记录的岩浆活动与 Góry Sowie 地块中麻粒岩和橄榄岩的高温/高压变质作用同时发生，将 CSO 的肢解部分分开。这表明 Góry Sowie 记录的大陆俯冲与 CSO 记录的海洋扩张之间存在地球动力学耦合。区域地质资料表明 CSO 在C。383 Ma，在海洋扩张中心形成后不到 20 Ma。CSO 被证明是华力斯坎带泥盆纪蛇绿岩中最古老和最先被发现的一种。CSO 可能起源于一个演化的弧后盆地，其中与俯冲有关的流体和熔体的影响随着时间的推移而增加，从在主要的洋中脊型岩浆岩形成过程中可以忽略不计到后期的强，形成了附加岩和其他次要岩性。