Imaging the Indian lithosphere beneath the Eastern Himalayan region
Imaging the Indian lithosphere beneath the Eastern Himalayan region
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DOI：
10.1111/j.1365-246x.2011.05185.x
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发表时间：
2011-11
影响因子：
2.8
通讯作者：
E. Devi;P. Kumar;M. Kumar
中科院分区：
文献类型：
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作者：
E. Devi;P. Kumar;M. Kumar
摘要岩石圈厚度是了解印度板块和亚洲板块之间碰撞和俯冲性质的一个重要参数。在这项研究中，我们应用S接收函数技术的数据从一个网络的宽带站在印度东北部和喜马拉雅山脉东部地区和图像的几何形状的印度板块碰撞。该分析揭示了明确的S-P转换莫霍面和岩石圈软流圈边界（LAB）在研究区域的各个构造单元。印度岩石圈被发现只有90公里厚的西隆高原下加深到135公里左右的岩石圈隆起有关的高原隆升暗示。岩石圈向北增厚，在东喜马拉雅山下厚度达到180公里。前渊区北部的LAB趋势表明印度板块俯冲到东喜马拉雅之下。印度板块持续的向北倾斜特征表明，印度板块在班公湖缝合带以南俯冲到西藏之下之前是可追踪的。LAB的加深及其与地形高程的相关性与印度与亚洲大陆碰撞产生的挤压力导致的岩石圈均匀增厚一致。
SUMMARY Lithospheric thickness is an important parameter to understand the nature of collision and subduction between the Indian and Asian tectonic plates. In this study, we apply the S receiver function technique to data from a network of broad-band stations in the northeast India and Eastern Himalayan regions and image the geometry of Indian Plate collision. This analysis reveals clear S-to-p conversions from the Moho and Lithosphere–Asthenosphere boundary (LAB) in the various tectonic units of the study region. The Indian lithosphere is found to be only 90 km thick beneath the Shillong plateau deepening to 135 km on either side suggestive of a lithospheric upwarp related to the plateau uplift. The lithosphere thickens northward, with values reaching ∼180 km beneath the Eastern Himalaya. The trend of the LAB north of the foredeep region indicates that the Indian Plate plunges beneath the Eastern Himalaya. The consistent northward-dipping character of the Indian Plate suggests that the Indian Plate is traceable until it gets subducted beneath Tibet just south of Bangong suture zone. The deepening of the LAB and its correlation with the topographic elevation is in agreement with homogeneous thickening of the lithosphere in response to compressive forces due to the continental collision of India with Asia.