In the vast territory along the Qinghai-Tibet railway now being built in some of western China's most hazardous landscapes, the ancestors of today's Chinese lived and prospered on a plateau with an average elevation of more than 4,000 metres above sea level and left us precious clues to their lives.

There had never been any overall investigation of the cultural relics in this territory until the end of May this year, when archaeologists from the Qinghai Provincial Cultural Relic and Archaeology Research Institute started large-scale fieldwork along the railway in Northwest China's Qinghai Province.

To date, they have found four historical sites and eight clusters of ancient tombs, where a number of microlithic implements were unearthed, according to Liu Baoshan, a researcher with the institute.

Microlithic implements - tools containing minute worked flint, often with stick handles - were widely used between the Palaeolithic Age and the Neolithic Age.

The implements made in this way are more standardized than the chopped-stone implements prevalent in the Palaeolithic Age.

Liu said: "Historical sites discovered in the investigation are the most important findings that provide clues to the microlithic culture in Northwest China."

According to Liu, only a few historical sites of microlithic culture have been found in China, and the two most important ones found before this investigation are in the central plains - the Shayuan historical site in Northwest China's Shaanxi Province and the Lingjing historical site in Central China's Henan Province.

In this investigation, archaeologists found the Sanchakou microlithic site and the Tuotuo River microlithic site.

The Sanchakou site is on the terrace to the north of the Sancha River and to the south of the Kunlun Mountains. On the terrace are seasonal streams and several lumps of earth, near which most of the stone implements were unearthed.

At the site, archaeologists found 64 stone implements, including cores, slabs and slices, as well as tools for carving, scraping or chopping.

Among the implements found, the three leaf-shaped stone implements are quite delicate. Made of hard quartz, they are between 2 and 3 centimetres long, semi-transparent, and have sharp blades. One of them can be used as an arrowhead.

Relatively few stone implements were discovered at the Tuotuo River site, where the weather is particularly bad, compared with the Sanchakou site. The site sits on a terrace on the south bank of the Tuotuo River, which is the origin of the Yangtze River.

Most of the implements unearthed at this site were made of light green silicon. The historical sites have not yet been dated, according to Liu Baoshan.

( China Daily July 31, 2002)