Precursor of the Highland silk road on the Tibetan Plateau

Ancient silk road had two main branches, one is north line across Xinjiang and the other is south line proposed as Highland Silk Road, jointing Tibetan Empire, Tang Dynasty and states in South Asia. Due to the harsh natural environment on the Tibetan Plateau (TP), a little archaeological work had carried out, and a few archaeological sites were excavated on the TP. How the highland silk road was developed is unclear.

In 2018, researchers from the Chinese Academy of Sciences (CAS) launched the second scientific expedition to the Qinghai-Tibet Plateau (STEP) that will last 5 to 10 years, following an expedition in the 1970s. Sponsored by the STEP, we had two systematic surveys along the Yarlung Tsangpo River regions, esp. the middle and lower regions to understand the prehistoric human activities on the central Tibetan Plateau where the mean altitude is above 4000 meters. We investigated the terraces along the River and its tributoraries, and terraces circled the lake banks. 99 archaeological sites were surveyed, including 58 new findings. The anthropic deposits were found at 31 sites and a profile was cleared at each site to collect dating materials. Charcoals and charred seeds were floated from the anthropic deposits and dated 60 samples by the AMS ¹⁴C.

In combination with previous published dates, we set up a brief history of human activities on the central TP that is, Neolithic people had occupied the Yarlung Tsangpo Valley in the third millennium BC, and moved along the River and its tributaries. The route of dispersal is similar with the historic highland silk road, indicating that this road had developed in prehistory.