Nature of the 650–km seismic discontinuity: implications for mantle dynamics and differentiation
Nature of the 650–km seismic discontinuity: implications for mantle dynamics and differentiation
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DOI：
10.1038/331131a0
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发表时间：
1988-01
期刊：
影响因子：
64.8
通讯作者：
A. .. Ringwood;T. Irifune
中科院分区：
文献类型：
--
作者：
A. .. Ringwood;T. Irifune
年轻的薄洋板块俯冲过程中的化学浮力关系使它们被困在600至700公里之间的重力稳定层中，该层部分隔离了上地幔和下地幔的对流系统。但是当成熟的厚板块俯冲时，它们的上层冷的分化层可能会突破这一屏障，并被下地幔的对流环流所夹带。由此产生的混合对流模型提供了一个有希望的解释的性质的地震间断在650公里的深度和地幔的地球化学演化。
Chemical buoyancy relationships during subduction of young, thin oceanic plates cause them to be trapped in a gravitationally stable layer between 600 and 700 km that partly isolates the convective systems of the upper and lower mantle. But when mature, thick plates are subducted, their upper, cool differentiated layers may break through this barrier and become entrained in the convective circulation of the lower mantle. The resultant hybrid convection model provides a promising explanation of the properties of the seismic discontinuity at 650km depth and the geochemical evolution of the mantle.