Magnetotelluric Image of Transcrustal Magmatic System Beneath the Tulu Moye Geothermal Prospect in the Ethiopian Rift
Magnetotelluric Image of Transcrustal Magmatic System Beneath the Tulu Moye Geothermal Prospect in the Ethiopian Rift
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DOI：
10.1029/2018gl080333
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发表时间：
2018-12
影响因子：
5.2
通讯作者：
F. Samrock;A. Grayver;H. Eysteinsson;M. Saar
中科院分区：
文献类型：
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作者：
F. Samrock;A. Grayver;H. Eysteinsson;M. Saar
大陆裂陷是由构造伸展和地幔上涌之间的动态相互作用引发的。减压熔融通过岩石圈弱化协助大陆分裂，并迫使熔融物向上流到地球表面。然而，关于熔体通过脆性地壳的运输和在狭窄的裂谷对齐的岩浆段下的储存的细节仍然很不清楚。在这里，我们提出了一个地壳尺度的电导率模型的岩浆段在埃塞俄比亚裂谷，来自大地电磁数据的三维相位张量反演。我们的地下模型表明，熔体迁移沿着预先存在的弱结构，并存储在两个主要的相互关联的水平上的不同浓度，促进对流热液系统的形成。所获得的穿壳岩浆系统的模型提供了新的见解裂谷机制，岩浆上升的演变，和潜在的地热储层。
Continental rifting is initiated by a dynamic interplay between tectonic stretching and mantle upwelling. Decompression melting assists continental breakup through lithospheric weakening and enforces upflow of melt to the Earth's surface. However, the details about melt transport through the brittle crust and storage under narrow rift‐aligned magmatic segments remain largely unclear. Here we present a crustal‐scale electrical conductivity model for a magmatic segment in the Ethiopian Rift, derived from 3‐D phase tensor inversion of magnetotelluric data. Our subsurface model shows that melt migrates along preexisting weak structures and is stored in different concentrations on two major interconnected levels, facilitating the formation of a convective hydrothermal system. The obtained model of a transcrustal magmatic system offers new insights into rifting mechanisms, evolution of magma ascent, and prospective geothermal reservoirs.