Structure of the Afar and Tanzania plumes based on the regional tomography using ISC data
Structure of the Afar and Tanzania plumes based on the regional tomography using ISC data
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基于 ISC 数据的区域层析成像的阿法尔和坦桑尼亚羽流结构
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发表时间：
2007
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通讯作者：
I. Koulakov
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作者：
I. Koulakov
建立深层动力学与白天地表观测过程之间的相关性是现代地球动力学的一个重要基础问题。地幔柱是地球不同地区火山活动和裂谷形成的主要原因，对地幔柱的研究在这个问题中占有特殊地位。东非裂谷坳陷系统和阿法尔三联结是地幔作用对近地表构造活动影响最显著的例子。该地区地幔动力学与裂陷作用的相关性引起了世界上许多学者的关注（如[1]）。由上升羽流引起的岩石圈拉离力的定量估计在[2]中估计。这些工作和大量其他观察结果表明，东非的裂谷作用正是由地幔作用引起的。阿法尔三联结（ATJ）是一个从大陆裂谷到海洋扩张的过渡案例（图1）。在ATJ周围观察到岩石圈发散的三个分支，它们彼此之间的角度几乎相等（120°）。两个分支（红海和亚丁湾）是早期的海洋，有突出的扩展区。第三个分支（埃塞俄比亚裂谷）是沿着非洲大陆延伸的一个大型洼地系统的开始，首先向西南延伸，然后向南延伸。东非裂谷的总长度超过2500公里。在距离ATJ约700公里处，裂谷减弱，然后沿着坦桑尼亚克拉通周围的两个分支（西部和东部裂谷）再次恢复。东部裂谷在文献中也被称为肯尼亚裂谷，而西部裂谷被称为坦噶尼喀裂谷（来自坦噶尼喀湖的名字）。沿整个长度的裂陷作用
Establishment of the correlation between deep dynamics and processes observed at the daytime surface is an important fundamental problem of modern geodynamics. The study of mantle plumes, which are responsible for volcanic processes and riftogenesis in different parts of the Earth, occupies a special place in this problem. The system of rift depressions in East Africa and the Afar triple junction is the most striking example of the influence of mantle processes on the near-surface tectonic activity. The correlation between mantle dynamics and riftogenesis in this region has attracted the attention of many scholars around the world (see, for example, [1]). Quantitative estimates of pull-apart forces in the lithosphere induced by an ascending plume are estimated in [2]. These works and a multitude of other observations demonstrate that rifting in East Africa is caused precisely by mantle processes. The Afar triple junction (ATJ) is a transition case from continental rifting to oceanic spreading (Fig. 1). Three branches of divergence of the lithosphere located at almost equal angles (120 ° ) with respect to each other are observed around the ATJ. Two branches (the Red Sea and the Gulf of Aden) are incipient oceans with prominent spreading zones. The third branch (the Ethiopian Rift) is the beginning of a large system of depressions extended along the African continent first to the southwest and then to the south. The total length of the East African Rift is more than 2500 km. At a distance of approximately 700 km from the ATJ, the rifting is attenuated and then resumes again along two branches around the Tanzania Craton (Western and Eastern rifts). The Eastern Rift is also called the Kenya Rift in the literature, while the Western Rift is called Tanganyika Rift (from the name of Lake Tanganyika). The riftogenesis along the entire length of the