Abstract The Tuareg shield in North-West Africa is composed of an assembly of Neoproterozoic continental and oceanic terranes, as well as Archean and Paleoproterozoic terranes separated by major continental shear zones. In the Silet terrane, the igneous suite of Silet-Taourirts is composed of post-collisional ring-complexes of ferroan alkaline and alkali-calcic granites. Six ring-complexes have been dated using the U–Pb SHRIMP technique on zircon. The alkaline Tin Erit (584.8 ± 2.0 Ma), Tihoiiarene (569.8 ± 4.8 Ma) and Tioueine (561 ± 6 Ma) complexes are older than the alkali-calcic Issedienne (538.7 ± 2.9 Ma), Tesnou (536.5 ± 6.7 Ma) and Ait Oklan (529.3 ± 3.1 Ma) complexes. Sharing an enriched mantle source, the complexes display a secular variation of crustal contamination marked by decreasing eHf(t). The oldest alkaline complexes are related to the tectonic escape of the Tuareg terranes to the north after the climax of Pan-African orogeny, while the youngest alkali-calcic complexes were emplaced after the 575-555 Ma intra-continental Murzukian event.

中文翻译：

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埃迪卡拉纪到 Fortunian“Taourirt”花岗岩环复合体中的锆石 U-Pb 和 Lu-Hf 同位素系统（Silet 和 In Tedeini 地体，图阿雷格地盾，阿尔及利亚）

摘要 非洲西北部图阿雷格地盾由新元古代大陆地体和大洋地体，以及被主要大陆剪切带分隔的太古代和古元古代地体的集合组成。在 Silet 地体中，Silet-Taourirts 的火成岩套由铁质碱性花岗岩和碱钙质花岗岩的碰撞后环复合体组成。使用 U-Pb SHRIMP 技术对锆石测定了六个环配合物的年龄。碱性 Tin Erit (584.8 ± 2.0 Ma)、Tihoiiarene (569.8 ± 4.8 Ma) 和 Tioueine (561 ± 6 Ma) 复合物比碱性-钙质 Issedienne (538.7 ± 2.9 Ma)、Tesnou (536.5 ± 6.7 Ma) 更古老Ait Oklan (529.3 ± 3.1 Ma) 复合体。这些复合体共享一个丰富的地幔源，显示出以 eHf(t) 降低为标志的地壳污染的长期变化。