Abstract The geodynamic significance of Adamawa Yade Domain in Cameroon is still highly debated. This paper presents mineralogical, geochemical, zircon U–Pb age and Hf isotopic data for NNE-trending garnet-bearing pyroxeno-amphibolite (GPAm) and amphibolite (Am) bodies exposed in the Ititin area located at the Northwestern border of the Adamawa-Yade domain in Cameroon. The GPAm and Am were dated by SIMS U–Pb zircon methods and yielded upper and lower intercept ages of 2065 ± 30 Ma and 557 ± 29 Ma, and 2054 ± 40Ma and 803 ± 320Ma, respectively. In the primitive mantle-normalized trace elements pattern, the metabasites display spike-like pattern, with enrichment in Th and La, and depletion in Nb, Zr, Hf, P and Ti although lower abundances are recorded in GPAm. GPAm yielded 176 Hf/177Hf initial ratios (0.281243 to 0.281491) with ϵHf (2.06Ga) values of −9.7 to −0.7 whereas the Am display 176 Hf/177Hf initial ratios (0.281143–0.281206) with values of ϵHf (t) of −12.2 to9.8. Geochemistry and geochronological data suggest that GPAm and Am originated from a subduction - modified lithospheric mantle and were emplaced at 2.06 Ga in a continental arc setting during the Paleoproterozoic event that formed the West Central Africa Fold Belt. Both the GPAm and Am were subsequently overprinted by the Pan-African orogeny.

中文翻译：

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喀麦隆阿达马瓦-亚德域西部边界发生 2.06 Ga 俯冲的证据：元素地球化学的约束、锆石 Hf 同位素和来自 Ititin 变碱石的锆石 U/Pb 年代学

摘要 喀麦隆阿达马瓦亚德域的地球动力学意义仍存在争议。本文提供了在位于阿达马瓦-亚德西北边界的 Ititin 地区出露的 NNE 趋势含石榴石辉石角闪岩 (GPAm) 和角闪岩 (Am) 体的矿物学、地球化学、锆石 U-Pb 年龄和 Hf 同位素数据。喀麦隆的域名。GPAm和Am采用SIMS U-Pb锆石方法测年，得到上下截距年龄分别为2065±30Ma和557±29Ma，以及2054±40Ma和803±320Ma。在原始地幔归一化的微量元素模式中，虽然在 GPAm 中记录到的丰度较低，但变碱石显示出尖峰状模式，富集 Th 和 La，并耗尽 Nb、Zr、Hf、P 和 Ti。GPAm 产生 176 Hf/177Hf 的初始比率（0.281243 至 0.281491），其中 ϵHf (2. 06Ga) 值为 -9.7 至 -0.7，而 Am 显示 176 Hf/177Hf 初始比率 (0.281143–0.281206)，ϵHf (t) 值为 -12.2 至 9.8。地球化学和地质年代学数据表明，GPAm 和 Am 起源于俯冲改造的岩石圈地幔，并在形成西中非褶皱带的古元古代事件期间在大陆弧环境中形成于 2.06 Ga。GPAm 和 Am 随后都被泛非造山运动覆盖。06 Ga 在形成西中非褶皱带的古元古代事件期间的大陆弧环境中。GPAm 和 Am 随后都被泛非造山运动覆盖。06 Ga 在形成西中非褶皱带的古元古代事件期间的大陆弧环境中。GPAm 和 Am 随后都被泛非造山运动覆盖。