Thirteen sites of prehistoric stone tools have been discovered by Chinese archaeologists during a field survey on the Qinhai–Tibet Plateau, indicating that human activity had reached the plateau region, which is at an average altitude of 4000 metres. Once there the owners of the stone implements would have had to endure low temperatures, harsh weather conditions, and an acute shortage of oxygen.
     According to the archaeologists, who are part of a 16-member excavation team created for the ongoing Qinhai–Tibet Railway Project, some of the tools could have been used for farming or hunting.
     Members of the team originate from Sichuan University, the northern province of Shaanxi, and Tibet, which previously had never contributed archaeologists to such a major project. The team has been working on the 700-kilometre Tibetan section of the railway since May 10.

Source: Xinhua News Agency (29 May 2003)