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本文概述了在西藏高原长达450公里左右的南北向测线上取得九次湖中水下爆炸地震记录的处理结果。通过数字处理、拟合和反演等计算,得出了该地区地壳与上地幔的成层结构和速度分布。 结果表明,该区整个沉积岩层厚约3—5公里,雅鲁藏布江以北到当雄地带,地壳巨厚达70—73公里;江南地区为68—45公里,并逐渐向南翘起。在成层地壳介质中发现下地壳中存在低速层,厚约10公里,速度为5.64公里/秒。分析认为,高原地形与巨厚地壳的形成是印度洋板块与欧亚板块碰撞以及长期挤压和内部物质运移的结果。
This article provides an overview of the results of nine seabed underwater explosion seismograms recorded on the north-south line about 450 km long in the Tibetan Plateau. The stratigraphic structure and velocity distribution of crust and upper mantle in this area are obtained through digital processing, fitting and inversion calculation. The results show that the whole sedimentary rock formation in this area is about 3-5 km thick, and the area to the north of the Yarlung Zangbo River reaches the Dangxiong zone. The crust is 70-73 km in thickness and 68-45 km in the southern part of the Yangtze River. In stratigraphic crustal media, there is a low velocity layer in the lower crust with a thickness of 10 km and a velocity of 5.64 km / s. The analysis shows that the formation of the plateau terrain and the thick crust are the result of the collision between the Indian Ocean plate and the Eurasian plate and the long-term extrusion and the internal material movement.