There should have been a residential complex in this site in the western outskirts of Chengdu. Instead, there is a huge hole in the ground whose contents have experts now scrambling to rewrite ancient Chinese history.

Workers of a local real estate development firm accidentally discovered what is now known as the Jinsha ruins more than a year ago, while preparing the area for construction.

Since then, archaeologists have been busy unearthing one important artifact after another, all of them indicating that there once was a civilisation that thrived here more than 3,500 years ago.

The Jinsha site, as well as that of the Sanxingdui ruins also found in this south-west Chinese province, has all but challenged the long-held notion that the Yellow River valley was the only cradle of Chinese civilisation.

According to experts here, everything that they have found so far in Jinsha and Sanxingdui suggest that a sophisticated bronze civilisation existed along the Yangtze River as early as the more well known civilisation in the Yellow River valley to the north.

But Wang Yi, head of the excavation team here, notes that one difference in the artifacts they have unearthed here and those in Yellow River valley kingdoms is the use of gold leaf by the ancient southern Chinese.

He says gold leaf was also used by central Chinese peoples while gold objects in the north were all solid, most of them jewellery pieces.

The southern Chinese apparently glued the gold leaf onto bronze or lacquer ware as enhancements or decorations.

Archaeologists here have found several pieces of gold leaf pieces, including a sun that is as thin as 0.02 cm and with a diameter of 12.5 cm. It has 12 long 'teeth' arranged in the shape of a whirlpool, as well as four phoenixes hollowed out of the piece.

Experts say the image of birds around the sun suggests that the ancient Jinsha state practised some form of totem worship. They add that sun worship was practised by the ancient people of Chengdu Plain.

Wang says one exceptional representative piece of the bronze culture of the Chengdu Plain is a mask with gold leaf that is about 3.74 cm in height and 4.92 in diameter. The mask has a big nose, crescent brows and almond eyes. Its mouth is half-open in a smile.

Sacrificial vessels

Similar masks have been found in Sanxingdui, some 40 km north of Chengdu. But experts say gold masks such as the one is Jinsha have never been found elsewhere in China.

According to Wang, this is probably because craftsmen elsewhere had not developed sophisticated techniques to deal with gold during the Shang and Zhou period (16th century BC to 221 BC).

Experts say there are strong indications that the Jinsha and Sanxingdui ruins are linked. Aside from having gold pieces done with similar techniques, both sites have been found to have jade sacrificial vessels that also look similar.

The jade ornaments recovered from Sanxingdui indicate that a civilisation flourished there about 3,700 to 5,000 years ago. Archaeologist think Sanxingdui could have served as the capital for several kings of the state of Shu, which was then a dominant power in southwest China.

Yu Weichao, a former curator of the Museum of Chinese History, meanwhile speculates that Jinsha may have been the political and cultural centre of the Shu state some 3,000 years ago, following the fall of the Sanxingdui civilisation.

Yu says that given the way that people intermingled and tended to stay in one place, especially when the place is as rich as the Chengdu Plain, the king of Shu probably moved to Chengdu, after the sudden collapse of the Sanxingdui settlement.

Covering four square kilometeres, Jinsha includes an area for holding sacrificial rites, a palace, and residences for commoners.

''The former two are exclusive premises for the noble class. It might belong to the king of the ancient state of Shu. The capital of Sichuan today, Chengdu, could be one of the capitals of Shu, ancient name for Sichuan,'' says Wang, who is also director of the Chengdu Archaeology Institute.

He says that a tonne of whole elephant tusks, which were among the 2,000 pieces of relics recovered so far from the site, could have been brought to the state of Shu by people from Yunnan to the south either as a tribute to the king or for barter trade.

But other experts note that unlike the Sanxingdui ruins where there is evidence of a city wall 2,600 metres long and at least three metres high, no trace of a city wall has been found at Jinsha.

With the absence of such a wall, whether or not Jinsha served as Shu's capital city is open to question, say these experts.

Wang theorises, though, that the ancient city wall could have been destroyed during the Cultural Revolution (1966-76).

Close relationship

In the meantime, experts say there is little question that Jinsha had a close relationship as well with civilisations that originated in the Yellow River valley, judging from the artifacts it has yielded.

These include tortoise shells used to practice divination that are similar to those found in the Yin ruins in central China's Henan province in 1928. The Yin artifacts are believed to date back to some 5,000 years.

Another Jinsha relic that indicates a connection to the lower reaches of the Yangtze River is a jade vessel whose engravings are almost identical with those on vessels that appeared in the late period of the Liangchu culture, which began 5,000 years ago in an area in south-east China.

That area comprises today's Shanghai and Zhejiang and Jiangsu provinces along the lower reaches of the Yangtze.

The Jinsha green jade vessel is horizontally carved into 10 sections with nine shallow grooves, bringing about 80 convex lines on the whole piece.

On these convex lines are engraved delicate lines that appear to stand for human faces, with circles and triangles symbolising eyes, and geometric figures symbolising mouths.

Also carved, in intaglio, on the vessel is what appears to be a deity, albeit a bit overweight and wearing a crown with accessories, standing with arms and legs spread out. On each arm is a feather ornament.

The vessel is round inside yet square outside. Experts say this design complies with ancient Chinese philosophical idea called ' tianyuan difang ', or the sky is round and the earth is square. In ancient times, such vessels were used for sacrificial purposes.

Wang says that this particular vessel was probably used by its owner to worship the heaven because of its green colour. He explains that yellow jade vessels were used to worship the earth. — IPS