The Mozambique Ridge: a document of massive multistage magmatism
The Mozambique Ridge: a document of massive multistage magmatism
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莫桑比克海岭：大规模多阶段岩浆作用的记录
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
R. Werner
中科院分区：
文献类型：
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作者：
M. Fischer;G. Uenzelmann‐Neben;G. Jacques;R. Werner
莫桑比克海脊是印度洋西南部的一个突出的基底高地，由四个主要的地貌段组成，与下白垩纪火山活动的许多阶段有关。莫桑比克海脊的性质和起源一直存在激烈的争论，有一种假说认为是大火成岩省的起源。高分辨率地震反射数据显示，在整个莫桑比克海脊南部和附近的特兰斯凯海隆有大量随机分布的挤压中心。基底内反射出现从挤出中心，并解释为代表大规模的熔岩流序列。这种熔岩流序列是导致大陆和海洋溢流玄武岩省形成的火山爆发的特征，因此支持莫桑比克海脊的大火成岩省起源。我们观察到广泛的沉积后岩浆活动的证据，我们与东非裂谷系向南传播。根据我们对莫桑比克海脊南部的体积分析，我们推断在131 ~ 125 Ma之间有一个快速的连续侵位过程，这与Agulhas高原等其他大火成岩省的短形成期相似。
The Mozambique Ridge, a prominent basement high in the southwestern Indian Ocean, consists of four major geomorphological segments associated with numerous phases of volcanic activity in the Lower Cretaceous. The nature and origin of the Mozambique Ridge have been intensely debated with one hypothesis suggesting a Large Igneous Province origin. High-resolution seismic reflection data reveal a large number of extrusion centres with a random distribution throughout the southern Mozambique Ridge and the nearby Transkei Rise. Intrabasement reflections emerge from the extrusion centres and are interpreted to represent massive lava flow sequences. Such lava flow sequences are characteristic of eruptions leading to the formation of continental and oceanic flood basalt provinces, hence supporting a Large Igneous Province origin of the Mozambique Ridge. We observe evidence for widespread post-sedimentary magmatic activity that we correlate with a southward propagation of the East African Rift System. Based on our volumetric analysis of the southern Mozambique Ridge we infer a rapid sequential emplacement between ∼131 and ∼125 Ma, which is similar to the short formation periods of other Large Igneous Provinces like the Agulhas Plateau.