Abstract Neoarchean orthogneiss, dated at 2629 ± 9 Ma by SIMS zircon U-Pb, has been discovered in the Rusizian terrane of the Western Domain of the Karagwe Ankole Belt, Rwanda, redefining the NW margin of the Tanzania Craton. Metamorphism of the orthogneiss at 1959 ± 4 Ma was associated with Paleoproterozoic granitic arc magmatism in the Rusizian terrane over the period ca. 2000–1840 Ma. The major and trace element composition of the peraluminous, calc-alkalic orthogneiss is consistent with magmatism in an arc setting at an active continental margin. Its Nd depleted mantle model age of ca. 2800 Ma is consistent with derivation by partial melting and reworking of older crust at the NW margin of the Tanzania Craton. The Paleoproterozoic thermal event was related to the accretional collision between the Congo and Tanzania Cratons during the assembly of the Nuna supercontinent. Future tectonic modelling of the Karagwe Ankole Belt must take into account the presence of Archean basement beneath the Western Domain.

中文翻译：

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卢旺达 Karagwe Ankole 带西部地区太古宙地壳的直接证据：对新太古代到古元古代地壳演化的影响

摘要 新太古代正方麻岩由 SIMS 锆石 U-Pb 测得的年代为 2629 ± 9 Ma，在卢旺达 Karagwe Ankole 带西域的 Rusizian 地体中被发现，重新定义了坦桑尼亚克拉通的 NW 边缘。1959 ± 4 Ma 的正​​方麻岩变质作用与俄罗斯地体中古元古代花岗岩弧岩浆作用有关。2000–1840 年 过铝质钙碱性正方麻岩的主要和微量元素组成与活动大陆边缘弧形环境中的岩浆作用一致。它的 Nd 耗尽地幔模型年龄约为。2800 Ma 与坦桑尼亚克拉通 NW 边缘老地壳的部分熔融和再加工推导一致。古元古代热事件与努纳超大陆组装期间刚果和坦桑尼亚克拉通之间的增生碰撞有关。Karagwe Ankole 带未来的构造建模必须考虑到西部领域下方太古代基底的存在。