In Central Africa, the Pan-African Yaoundé group is made up of migmatites and gneisses exhumed and thrusted on micaschists. In a window in the micaschists, the Mamb metagabbro massif occurs as km-size and ca 20 m-high hill crosscut by a 15 m-thick dyke of meta-hornblendite. Minor facies are biotitites, garnetites, and granitic veins. Metagabbro comprises pargasite, biotite, labrador-andesine, pyrope- andradite- grossular-rich almandine, epidote, FeTi oxide, quartz, scapolite, rutile, zircon, and late metamorphic muscovite, whereas meta-hornblendite is made up of abundant edenite-pargasite, and minor amounts of plagioclase, biotite and epidote. Textural features such as epidote needles in plagioclase and rutile exsolutions in amphibole suggests that metamorphism (P-T conditions: 610 °C and 9.1 Kb) post-dated magma emplacement and crystallisation. Based on ⁴⁰Ar/³⁹Ar thermochronology of amphibole and micas, the proceedings of metamorphic processes extended from 601 to 586 Ma. Chemically, metagabbros and meta-hornblendites display hybrid adakitic and calk-alkaline characteristics. Mantle-normalised element patterns of metagabbros are marked by negative Nb, Ta, Zr, Hf, Ti, Y and positive Sr and Pb anomalies parallel to metadiorites of Yaoundé. Meta-hornblendite patterns show depletion in Th, K, and Pb similarly to alkaline rocks but high values of Y/Nb (> 3) and Zr/Nb (11–52) ratios point to a subalkalic affinity. Characteristics of these metagabbros and meta-hornblendites point to heterogeneous origins by partial melting of a dehydrated subducted hot oceanic crust and the fusion of a metasomatised mantle wedge. Metadiorites from Yaoundé are arc related rocks. Thus it appears that the island arc setting described at Boumnyebel extends eastwards up to Yaoundé, and probably up to Lomié in the south-eastern Cameroon. The northwards extension of this setting is yet to be established taking into account the presence of Archaean-Paleoproterozoic formations north of the continental scale Sanaga shear zone. At the regional scale, the best model to explain the presence of adakites and classic arc magmas at Mamb, Bape, Bangangté and Fomopea is a south-north subduction of the Pan-African Yaoundé hot oceanic crust under the Archaean Adamawa-Yade block.

在中部非洲，泛非的雅温得小组是由云母和片麻岩组成的，这些云母和片麻岩被挖掘出并注入云母。在云母岩的一个窗口中，Mamb metagabbro地块以千米大小，约20 m高的山横切面出现，由15 m厚的变质角闪长岩堤构成。次要相是黑云母，石榴石和花岗岩脉。Metagabbro包括辉石，黑云母，拉布拉多-安地辛，发烟表和辐射-富含大锰铁的石蒜，附子，铁氧化钛，石英，方沸石，金红石，锆石和晚变质白云母，而变角质钠长石则由丰富的辉石-辉石，少量斜长石，黑云母和附子组成。纹理特征（如斜长石中的附子针和角闪石中的金红石溶液）表明，岩浆侵位和结晶作用较晚（PT条件：610°C和9.1 Kb）。基于⁴⁰ Ar / ³⁹闪石和云母的Ar热年代学，变质过程从601 Ma扩展到586 Ma。在化学上，斜长石和斜长角石显示出混合的adakitic和calk-碱性特征。偏斜幔的地幔归一化元素模式以负的Nb，Ta，Zr，Hf，Ti，Y以及与Yaoundé的闪长岩平行的正Sr和Pb异常为特征。与碱性岩石相似，元角闪长岩模式显示出Th，K和Pb的枯竭，但是Y / Nb（> 3）和Zr / Nb（11-52）的高值表明其具有弱碱性。这些变质岩和变长角质岩的特征通过脱水的俯冲的热洋壳的部分熔融和变质的地幔楔的融合而指向异质起源。雅温得的闪长岩是与弧有关的岩石。因此，似乎在Boumnyebel中描述的岛屿弧形环境向东延伸至Yaoundé，并可能延伸至喀麦隆东南部的Lomié。考虑到大陆规模的Sanaga剪切带以北的太古宙古生代地层的存在，尚未确定该区域的向北延伸。在区域尺度上，解释Mamb，Bape，Bangangté和Fomopea的黄ak石和经典弧形岩浆存在的最佳模型是古非洲Yaoundé地壳在古生的Adamawa-Yade区块下的南北俯冲。考虑到大陆规模的Sanaga剪切带以北的太古宙古生代地层的存在，尚未确定该区域的向北延伸。在区域尺度上，解释Mamb，Bape，Bangangté和Fomopea的黄ak石和经典弧形岩浆存在的最佳模型是古非洲Yaoundé地壳在古生的Adamawa-Yade区块下的南北俯冲。考虑到大陆规模的Sanaga剪切带以北的太古宙古生代地层的存在，尚未确定该区域的向北延伸。在区域尺度上，解释Mamb，Bape，Bangangté和Fomopea的黄ak石和经典弧形岩浆存在的最佳模型是古非洲Yaoundé地壳在古生的Adamawa-Yade区块下的南北俯冲。