Initial burst of oceanic crust accretion in the Red Sea due to edge-driven mantle convection
Initial burst of oceanic crust accretion in the Red Sea due to edge-driven mantle convection
复制标题
由于边缘驱动的地幔对流，红海洋壳增生的最初爆发
DOI：
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
N. Rasul
中科院分区：
文献类型：
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作者：
M. Ligi;E. Bonatti;F. Tontini;A. Cipriani;L. Cocchi;A. Schettino;G. Bortoluzzi;V. Ferrante;S. Khalil;N. Mitchell;N. Rasul
500米大陆聚集成一个超级大陆，然后再次分裂和分散的循环涉及大陆的破裂和新海洋的诞生，并形成被动板块边缘。今天，阿拉伯与非洲分离的红海充分展示了这一过程。我们在红海最北端的两个最初洋壳增生的轴向部分——忒提斯和海神星进行了地球物理调查和底部岩石采样。地壳厚度、磁场强度和近轴上涌地幔熔化程度的区域变化揭示了活跃洋壳生成的初始爆发和每个细胞下方的海底快速扩张，一旦大陆岩石圈盖破裂就会发生。这种初始脉冲可能是由边缘驱动的裂谷地幔对流引起的，该对流是由冷大陆岩石圈和热上升软流圈之间强大的水平热梯度触发的。随着大洋裂谷的扩大，热梯度减弱；因此，最初的主动脉冲逐渐变成稳定的、更被动的地壳增生，传播速度较慢，并沿轴裂谷传播。
The 500 m.y. cycle whereby continents assemble in a single supercontinent and then fragment and disperse again involves the rupturing of a continent and the birth of a new ocean, with the formation of passive plate margins. This process is well displayed today in the Red Sea, where Arabia is separating from Africa. We carried out geophysical surveys and bottom rock sampling in the two Red Sea northernmost axial segments of initial oceanic crust accretion, Thetis and Nereus. Areal variations of crustal thickness, magnetic intensity, and degree of melting of the subaxial upwelling mantle reveal an initial burst of active oceanic crust generation and rapid seafloor spreading below each cell, occurring as soon as the lid of continental lithosphere breaks. This initial pulse may be caused by edge-driven subrift mantle convection, triggered by a strong horizontal thermal gradient between the cold continental lithosphere and the hot ascending asthenosphere. The thermal gradient weakens as the oceanic rift widens; therefore the initial active pulse fades into steady, more passive crustal accretion, with slower spreading and along axis rift propagation.
影响因子：
4.9
作者：
Mitchell N
通讯作者：
Mitchell N