After more than a year's excavation and research in Northwest China, archaeologists now believe an ancient tomb belonged to the grandmother of Qinshihuang, the country's first emperor.

Zhang Tian'en, an expert with the Shaanxi Provincial Archaeology Institute, said the tomb was probably built on the emperor's orders and was chronologically the closest to the mysterious mausoleum of Qinshihuang.

It is estimated that more than 720,000 workers laboured 38 years to build the mausoleum for the emperor, who ruled the Qin Dynasty, China's first unified dynasty, from 221-206 BC.

"We are hoping that the excavation of his grandmother's tomb will help unravel the mystery about the first emperor's mausoleum, which still cannot be excavated. It will also contribute to research into Qin Dynasty burial culture," Zhang said.

The tomb, located on the southern outskirts of Xi'an, provincial capital of Shaanxi, is the second largest ancient tomb excavated in China.

Only the tomb of King Jinggong of the State of Qin (897-221 BC) is bigger, said Zhang.

Located under the new campus of the Xi'an Business College, the tomb is about 30 kilometres southwest of Qinshihuang's famous mausoleum. Qinshihuang united seven warring states and founded the Qin Dynasty in 221 BC.

With a length of 550 metres and a width of 310 metres, the tomb covers an area of 17.3 hectares.

Archaeologists unearthed two carriages designed to be driven by six horses, which could only be used by kings and queens in the State of Qin.

The seals of court officials responsible for running errands on behalf of queens, queen mothers and princes, have also been found, said Wang Hui, an expert with Shaanxi Normal University.

After further examination on the unearthed articles and comparisons with Qin mausoleums, the archaeologists concluded that the tomb belonged to Qinshihuang's grandmother, Queen Mother Xia.

Ding said that since the tomb was raided and burned several times, only fragments of Qin coins, grey clay vases and red clay boilers have been unearthed, as well as shards of decorative and ritual jade objects, broken pottery and pieces of bronze.

Sadly, Qingshihuang's grandmother's inner and outer coffins were also burned, Ding added. The tomb is still under excavation.

Zhang Tian'en said the Queen Mother lived until Qinshihuang was 20 in the seventh year of his reign. The royal lady is believed to have exerted considerable influence on the politics of the later years of the State of Qin and on Qinshihuang in particular.

China's survey of the 2,200-year-old Qinshihuang mausoleum has lasted nearly 40 years. What has been discovered is believed to be just the tip of the iceberg. The site remains a mystery even if the terra cotta warrior underground army has long been unearthed and hailed as the world's eighth wonder.

"The best choice is to leave the ancient tomb untouched because, given the complicated conditions inside, excavation errors could lead to its destruction," said Duan Qingbo, a top archaeologist with the Shaanxi Provincial Archaeology Institute.

"Current techniques cannot ensure that the mausoleum will be properly protected after excavation."

Archaeologists, using remote sensing equipment, have located symmetrical staircases leading down into the tomb and wooden structures inside the tomb.

They have also discovered that the tomb was built with an effective drainage system that has prevented ground water from seeping inside, according to Duan.

Legends maintain that a huge underground palace was modeled on the emperor's realm with rivers flowing with mercury and the ceiling studded with pearls and diamonds representing the stars and sun.

"Our survey shows that the mercury density in Qinshihuang's cemetery area is vastly higher than that in the surrounding area, and confirms that the mercury comes from the mausoleum," Duan said.

The mausoleum was also said to have architectural designs that archaeologists believe have successfully kept out tomb robbers.

Stone top retrieved

The eight-square stone top is 24 centimeters thick, with the longest diagonal of the top surface 70 centimeters and Buddhist patterns including lotus petals, curtains, streamers and pearls carved on each side.

It fits the pillar trunk engraved during the Tang Dynasty (AD 618-907) and re-discovered in June in Anle, Henan Province, the same town where the top was found, experts say. The octahedral pyramid trunk, 142 centimeters high and 2,000 kilograms in weight, was collected by a local folklore museum.

Experts are repairing and studying the stone pillar, which will be shown to the public soon, a source with the local cultural relic bureau said.

Oldest piece of paper

The 10-square-centimetre piece of paper, made from linen fibres, was found during restoration of an ancient garrison near the Yumen Pass at Dunhuang in Northwest China. The garrison was in use during the Western Han Dynasty (206 BC-AD 25), a report in the Beijing-based Guangming Daily said. Experts say so far over 20 ancient Chinese characters on the paper have been identified, and that the piece of paper was likely part of a letter.

"The paper was made in 8 BC, more than 100 years ahead of Cai Lun, who used to be widely considered the inventor of paper-making process in China. It also shows that the ancient Chinese have been writing on paper for much longer than we thought," said Fu Licheng, curator of the Dunhuang Museum.

Cai Lun, a craftsman of the Eastern Han Dynasty (AD 25-220) imperial court, is now believed by experts to have improved the paper-making process in AD 105, making paper possible for mass production. Cai's paper-making process used tree bark, cloth, and fishing nets as raw materials.

According to the report, ancient paper has been found over the last 20 years in Dunhuang, which used to be one of the ancient Chinese military strongholds, and a major exchange spot on the Silk Road. The oldest piece of paper found by now was made in about 65 BC, 170 years ahead of Cai Lun. But no handwriting was found on the previously found paper.

Paper is prided as one of the four great inventions of the ancient Chinese, alongside moveable-type printing, gunpowder and the compass. The light, durable, yet cheap paper became most commonly used material for people to write on after the 16th century. Prior to the invention of paper, people used various materials for writing, including clay tablets, palm leaves, goatskins, bones, bamboo, silk and papyrus, an Egyptian plant.

(China Daily August 15, 2006)