Partially molten middle crust beneath southern Tibet: Synthesis of project INDEPTH results
Partially molten middle crust beneath southern Tibet: Synthesis of project INDEPTH results
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DOI：
10.1126/science.274.5293.1684
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发表时间：
1996-12-06
期刊：
影响因子：
56.9
通讯作者：
Edwards, M
中科院分区：
文献类型：
--
作者：
Nelson, KD;Zhao, WJ;Edwards, M
深入的地球物理和地质观测表明，在西藏南部下方存在一个部分熔融的中地壳层。这个部分熔融层是由地壳增厚产生的，并且在喜马拉雅变形的时间尺度上表现得像一种流体；它在南部受到特提斯和高喜马拉雅山脉下方构造叠瓦状的印度地壳的限制，并且显然下方是一个坚硬的印度地幔盖层。研究结果表明，在新近纪时期，俯冲的印度地壳起到了活塞的作用，将熔融的中地壳向北推移，同时通过熔融和韧性流动对该层有所贡献。从广义上看，喜马拉雅山脉的新近纪演化本质上是西藏南部下方部分熔融的中地壳向南挤出的记录。
INDEPTH geophysical and geological observations imply that a partially molten mid-crustal layer exists beneath southern Tibet, This partially molten layer has been produced by crustal thickening and behaves as a fluid on the time scale of Himalayan deformation; it is confined on the south by the structurally imbricated Indian crust underlying the Tethyan and High Himalaya and is underlain, apparently, by a stiff Indian mantle lid. The results suggest that during Neogene time the underthrusting Indian crust has acted as a plunger, displacing the molten middle crust to the north while at the same time contributing to this layer by melting and ductile flow. Viewed broadly, the Neogene evolution of the Himalaya is essentially a record of the southward extrusion of the partially molten middle crust underlying southern Tibet.