摘要
强烈遭受南北向挤压下的西藏高原上却发育了大量的正在活动着的东西向伸展构造 ,即裂谷系 .特别是在挤压力最为集中的喜马拉雅碰撞弧的前方 ,拉萨地体内发育了大规模、有规律排列的近南北向裂谷系 .目前 ,在拉萨地体内 ,开展了大量的地球物理探测和地质研究工作 ,如亚东—格尔木地学断面 ,INDETPH ,中法合作项目等 .鉴于当时的认识和科学研究目标 ,这些成果并没有把所有的裂谷系所发育的环境作为一个整体去研究 .因此 ,裂谷系的深部过程及其原由还是知之甚少 .本文在总结前人研究成果的基础上认为 ,从整个岩石圈流变学结构去研究藏南近南北向裂谷系将有助于去认识其产生这些裂谷系的深部动力学过程 ,进而能够更好地去认识西藏高原隆升的地球动力学过程 .
A large numbers of near east west quaternary extensive structure, Rifts, which are active at present, form in the Tibet Plateau, although Tibet Plateau is strongly pressed from north south stress. Especially in the Lhasa Terrane before the collision arc where the press stress is most concentrated, there are many large scale rifts that regularly lay out. At present, many deep geophysical probings and geological surveys have been carried out in the Lhasa Terrane, such as Yadong Golm GGT, INDEPTH, and Sino France Cooperation etc. Maybe due to their scientific research object and viewings to Tibet then, those projects had not done research on the importance of the development environments of these rifts in Lhasa Terrane, as a whole, to uplift of Tibet plateau. Thus, some deep processes of rifts and its seed is nothing to be known. On the basis of the summary on presents achievements, the research on near north south quaternary rifts in south Tibet as a whole of lithopheric rheology, by integrated geophysics, and combined geology, tectonics and geochemistry etc, is helpful to understand rheological structure and deep geodynamic process which form rifts. Also, it is useful to know the whole geodynamic process of Tibet Plateau uplifting.