Large silicic magma reservoirs preferentially form in the upper crust of extensional continental environments. However, our quantitative understanding of the link between mantle magmatism, silicic reservoirs, and surface deformation during rifting is very limited. Here, we focus on Corbetti, a peralkaline caldera in the densely populated Main Ethiopian Rift, which lies above a focused zone of upper mantle partial melt and has been steadily uplifting at a maximum rate of 6.6±1.2 cm yr⁻¹ for more than 10 yr. Numerical modeling shows that a maximum concomitant residual gravity increase of 9±3 μGal yr⁻¹ by the intrusion of mafic magma at ∼7 km depth into a compressible and inelastic crystal mush best explains the observed deformation and gravity changes. The derived magma mass flux of ∼10¹¹ kg yr⁻¹ is anomalously high and at least 1 order of magnitude greater than the mean long‐term mass eruption rate. This study demonstrates that periodic and high‐rate magmatic rejuvenation of upper‐crustal mush is a significant and rapid contributor to mature continental rifting.

中文翻译：

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延性和可压缩性适应硅质大陆裂谷破火山口下的高岩浆通量：来自科贝蒂破火山口的见解（埃塞俄比亚）

大型硅质岩浆储集层优先形成于伸展大陆环境的上地壳中。但是，我们对地幔岩浆作用，硅质储集层和裂谷过程中地表变形之间联系的定量理解非常有限。在这里，我们关注Corbetti，这是人口稠密的埃塞俄比亚主要裂谷中的碱性碱性破火山口，其位于上地幔部分熔融的聚焦区域上方，并且以6.6±1.2 cm yr ^-1的最大速率稳定抬升超过10个年。数值模型表明，镁铁质岩浆在约7 km的深度侵入可压缩非弹性晶体中，最大伴随残余重力增加了9±3μGalyr ^-1，这最能说明观察到的形变和重力变化。导出的岩浆质量通量约为10¹¹  kg yr ^-1反常很高，比平均长期群发率大至少1个数量级。这项研究表明，上地壳糊状物的周期性和高速率的岩浆回生作用是成熟大陆裂谷的重要且迅速的原因。