【摘要】 龙木错-双湖缝合带、西金乌兰-金沙江缝合带和昆仑-秦岭缝合带是青藏高原上3条主要的晚三叠世板块缝合带,目前的研究资料表明后2条缝合带不具备冈瓦纳北界的基本要素。简要介绍了龙木错-双湖缝合带中有关古特提斯洋存在的基本事实,即早古生代洋壳残片、二叠纪蛇绿岩、泥盆纪—二叠纪放射虫硅质岩、各类不同性质的增生岩片、2种类型的构造混杂岩带和蛇绿混杂岩盖层体系的时代与性质等,已有的资料初步确定羌塘古特提斯洋盆演化的时限为晚泥盆世到晚三叠世。认为龙木错-双湖缝合带是青藏高原上古特提斯洋消亡的主要场所,是恢复和反演青藏高原早期形成演化的最重要的窗口,也是地学界几十年关注的冈瓦纳大陆的北界。更多还原

【Abstract】 Three Late Triassic plate sutures, namely, the Lungmu Co-Shuanghu suture, Kunlun-Qinling suture and Xijir Ulan-Jinsha River suture, have been recognized on the Qinghai-Tibet Plateau. Data show that the last two sutures have no essential elements of the northern boundary of Gondwana. This paper briefly introduces the basic fact of the existence of the Paleo-Tethys Ocean in the Lungmu Co-Shuanghu suture, i.e. the ages and natures of Early Paleozoic ophiolites, Permian ophiolites, Devonian-Permian radiolarian cherts, accretionary slabs of different natures, two types of tectonic mélange zones and covers of ophiolites. The starting time of the Paleo-Tethys Ocean in Qiangtang may be traced back to Early Paleozoic and the records about the oceanic basin evolution persisted from the Late Devonian to Late Triassic. It is thought that the Lungmu Co-Shuanghu suture was the site for the extinction of the Paleo-Tethys Ocean on the Qinghai-Tibet Plateau and an important window for the reconstruction and inversion of the early-stage formation and evolution of the Qinghai-Tibet Plateau, as well as the northern boundary of Gondwana that the geoscience community has paid attention to in the past few decades.更多还原