The Longmu Co-Shuanghu-Jitang plate suture and the northern boundary of Gondwanaland in the Qinghai-Tibet plateau

Abstract

The location of the northern boundary of Gondwanaland has been a topic of discussion for many years. As geologic research on Qinghai-Tibet plateau has progressed, Qiangtang has become the key area for resolving this problem. According to published data, there are three Indosinian plate sutures in the plateau, which divide it into three structural domains. They are the Tarim-North China domain north of the Kunlun-Qinling suture, the Yangtze domain between the Kunlun-Qinling and Longmu Co-Shuanghu-Jitang sutures, and the Gondwanaland domain south of the Longmu Co-Shuanghu-Jitang suture. We consider the Xijinwulan-Jinshajiang suture as an additional Indosinian suture which developed within the Yangtze plate. The Bangong Co-Nujiang and Yarlung Zangbo sutures developed within the Gondwanaland domain, but neither can be considered to define the northern boundary of Gondwanaland. We disscuss the Longmu Co-Shuanghu-Jitang suture and its relationships to the geology of the Gondwanaland and Yantze domains. Based on our comparative study of the Indosinian sutures, we consider the Longmu Co-Shuanghu-Jitang suture to define the Neopaleozoic northern boundary of Gondwanaland.