【摘要】 本文概述亚东—格尔木地学断面的地球物理研究成果.在前人工作基础上,沿断面补做了多方法地球物理调查,对原有资料重新解释,综合新、老资料,给出了断面岩石层构造的地球物理解释模型.研究结果认为,青藏高原是一个拼合的增生大陆,是世界上一种新型的俯冲加逆冲叠覆的复杂类型造山带.更多还原

【Abstract】 In addition to the previous work, we have done the following geophysical measurements: paleomagnetic measurement on 2000 samples, gravity profiling from Lhasa to Golmud, magnetic profiling from Yadong to Golmud, MT measurement (period: 0.01-10000s) and heat flow survey (12 values obtained). Image processing has been carried out with respect to the regional gravity and magnetic anomalies. Seis-81 are used to reinterpret the available seismic data. An interactive system incorperating seismic, gravity, magnetic and MT data is developed to set up a geophysical model for the Qinghai-Tibet Plateau.based on the preliminary results, we obtained the following conclusions: 1. Qinghai-Ti-bet Plateau consists of six terranes which seperated from Gonwana during Paleozoic and Me-sozoic successively, and latter accreted and united to the margih of the Eurasian continent at different erogenic times; 2. The tectonics of the southern and northern parts of the Plateau are different if the Ando-Dengqen fault is taken as a boundary. In the south, the lithosphere is more active, the crust is thick and the upper mantle making up the lithosphere is thin, and there exist two layers of high conductivity and low velocity. The crust is hot, and the collision time is later than that of the northern part of the Plateau. The lithosphere of the northern part, on contrast, is relatively stable, both the crust and the upper mantle are thick. The layer of low velocity and high conductivity is located at a shallow depth. The crust here is relatively cool, and the collision of the blocks took place earlier; 3. The slant of earhquake focus plane shows that the Plateau is mainly suffering the compression of the Idian plate and the resistance of the Eurasian plate, or the stress from the north. This results in the thicken-ing and shortening, and consequently the uplifting of the Qinghai-Tibet Plateau; 4. In comparison with the Andes orogenic belt(subduction) and the Alps orogenic belt (obduction and overlaping), the Qinghai-Tibet Plateau is a new type of orogenic belt characterized by obduction and overlaping, as well as subduction.更多还原