The initiation of segmented buoyancy-driven melting during continental breakup.
The initiation of segmented buoyancy-driven melting during continental breakup.
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DOI：
10.1038/ncomms13110
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发表时间：
2016-10-18
影响因子：
16.6
通讯作者：
Ahmed, Abdulhakim
中科院分区：
文献类型：
--
作者：
Gallacher, Ryan J.;Keir, Derek;Harmon, Nicholas;Stuart, Graham;Leroy, Sylvie;Hammond, James O. S.;Kendall, J-Michael;Ayele, Atalay;Goitom, Berhe;Ogubazghi, Ghebrebrhan;Ahmed, Abdulhakim
大陆破裂期间地幔熔化导致岩浆侵入和火山活动，但由于缺乏对地幔熔化的直接观测，我们对裂谷环境中熔体生成的位置和主要机制的理解受到阻碍。目前尚不清楚在裂谷过程中，海底扩张典型的岩浆供应分段性质何时开始。在这里，我们使用瑞利波层析成像技术构建了阿法尔三联结下方 250 公里上部的高分辨率绝对三维剪切波速度模型，对渐进大陆裂解过程中的地幔响应进行了成像。我们的模型表明，在大陆分裂早期，熔体产量最高，熔体深度最深。大陆裂谷期间熔体产量增加可能是由于裂谷狭窄时局部变薄和熔体聚焦所致。此外，我们解释了裂谷下方熔体供应的分段区域，这表明浮力驱动的地幔主动上涌在大陆裂谷早期就开始了。 我们对早期大陆分裂期间熔体产生的了解仍然很有限。 Gallacher 等人以阿法尔三联点为例。生成的 3D 速度模型表明，由于地壳局部变薄，早期大陆分裂期间熔体产量最高。
Melting of the mantle during continental breakup leads to magmatic intrusion and volcanism, yet our understanding of the location and dominant mechanisms of melt generation in rifting environments is impeded by a paucity of direct observations of mantle melting. It is unclear when during the rifting process the segmented nature of magma supply typical of seafloor spreading initiates. Here, we use Rayleigh-wave tomography to construct a high-resolution absolute three-dimensional shear-wave velocity model of the upper 250 km beneath the Afar triple junction, imaging the mantle response during progressive continental breakup. Our model suggests melt production is highest and melting depths deepest early during continental breakup. Elevated melt production during continental rifting is likely due to localized thinning and melt focusing when the rift is narrow. In addition, we interpret segmented zones of melt supply beneath the rift, suggesting that buoyancy-driven active upwelling of the mantle initiates early during continental rifting. Our understanding of melt production during early continental breakup remains poorly constrained. Using the Afar triple junction as an example, Gallacher et al. generate a 3D velocity model suggesting that melt production is highest during early continental breakup due to localised thinning of the crust.
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影响因子：
16.6
作者：
Keir, Derek;Belachew, M.;Ebinger, C. J.;Kendall, J. -M.;Hammond, J. O. S.;Stuart, G. W.;Ayele, A.;Rowland, J. V.
通讯作者：
Rowland, J. V.
影响因子：
64.8
作者：
BONATTI, E
通讯作者：
BONATTI, E
影响因子：
3.5
作者：
Holtzman, Benjamin K.;Kendall, J. -Michael
通讯作者：
Kendall, J. -Michael
影响因子：
5.8
作者：
Bridges, David L.;Mickus, Kevin;Alemu, Abera
通讯作者：
Alemu, Abera
影响因子：
64.8
作者：
Armitage, John J.;Collier, Jenny S.;Minshull, Tim A.
通讯作者：
Minshull, Tim A.