Sanxingdui Pit 5 was packed up and shipped out in its entirety on 4 March

Over 750kg of soil was wrapped tightly in a wooden box and slowly lifted out of the ground. When the "big thing" was steadily moved to a trolley, there was a big round of applause - it worked!

This is the site of the integral cutting and relocation of Pit5 of the Sanxingdui ritual area.On 4March , after more than a month of research, simulated relocation and continuous cutting and packing, Pit5 of the Sanxingdui Ritual Area was successfully cut and relocated to the Cultural and Conservation Centre of the Sanxingdui Museum. In the future, the 'gold Pit', where gold masks and a large number of gold leaf and ivory carving fragments were found, will continue to undergo laboratory archaeology, dedicated to unlocking the secrets behind the Pitfull of gold artifacts.

WHYMOVED?

Small area with manyartifactsNot convenient for on-site excavation

Sanxingdui Pit5, the smallest and most mysterious of the six newly discovered ritual Pits. During the excavations early last year, a fragmentary gold mask stunned the nation in one fell swoop. As the archaeological work progressed, the beautiful bird-shaped gold leaf piece was also revealed. In addition, a gold crown, a scattering of fine gold leaf and gold flakes, and a beautiful ivory carving with string, cloud and thunder, and feather and wing motifs were also found in Pit5. At a glance, Pit5 is resplendent.

However, following the excavation of the artifact layer early last year, the excavation of Pit5 has been largely suspended. For archaeological and conservation experts, it is very difficult to carry out non-contact archaeological excavations in Pit5. According to Li Haichao, a professor at Sichuan University, who was in charge of the excavation in Pit5, Pit5 was only about three square metersin size and had a large number of gold leaf pieces and ivory carvings scattered around the Pit, in addition to the gold mask extracted last year. These gold foil flakes in particular have round holes and are arranged in an orderly fashion, which may conceal valuable information. In addition, Pit5 may also contain information about microscopic traces that are difficult to identify with the naked eye, such as textiles that have been charred and muddied and other organic matter.

These are artifactsthat once immediately drew the bold imagination of experts - was the gold mask an ornament attached to the face of the Great Rising Man? Was the bird-shaped gold leaf worn around the neck as decoration? Could the large number of gold leaf pieces have been threaded through and hung in strings from clothing? Could they have been used by the ritualists as a symbol of status? In addition, the archaeologists found a large number of scattered gold beads in the pit, some of which are less than a millimetre in diameter and some of which are not very large even under a microscope. These gold beads contain 99 percentgold; were they consciously made or did they melt like this as a result of the fire? Again, evidence is needed to support this.

Considering that the relics from Pit 5 are numerous and finely fragmented, the relationship between the assemblage of relics cannot be determined, making on-site extraction more difficult. In addition, equipment such as x-ray detectors and CT tests were unable to enter the pit to explore more of the relic layers. Experts believe that the on-site archaeological excavation of Pit 5 can no longer meet its conditions for excavation, conservation and research, and that it needs to be relocated to the laboratory for more scientific and refined extraction and conservation research by means of an overall split extraction. The proposal to relocate the excavation back to the laboratory was approved by Li Cunxin, a renowned expert in cultural conservation from the Institute of Archaeology, Chinese Academy of Social Sciences, and others.

HOW TO MOVE?

Two simulations to make sure nothing goes wrong

On 17 January, Pit 5 was divided into two areas, Area 1 and Area 2, to begin the zoned cutting and relocation. Prior to this, the cultural and conservation staff carried out two 1:1 simulations of the relocation, solving the problems of not damaging the walls of the pits and the distribution of the remains, as well as the cutting process and the reinforcement process of the sets of boxes, before the actual operation began.

This is a complex project. Ren Junfeng, a heritage restorer at the Cultural Conservation Centre of the Sichuan Research Institute of Cultural Relics and Archaeology, was the site manager for the relocation. According to him, there was only a few centimeters of space between the cutting body and the wall of Pit 5, which contains the artifacts, and the walls of Pit 5 were not flat when excavated by the ancients. In order to avoid damaging the pit wall and the cutting body, the staff could only dig slowly with a custom-made "large digging spoon" on a U-shaped operating platform. They dug deeper along the wall to a depth of 110cm from the mouth of the pit, exposing the pit as an island, before cutting from the bottom and eventually moving the cut body out of the pit. Fortunately, the northeast corner of Area 1 was revealed by the exploratory hole to be free of buried artifacts and therefore became a valuable operational area for the crew. After the removal of Area 1, space was then sought for the relocation of Area 2.

The journalistsaw a variety of miniature tools custom-made by the cultural preservation staff at the site. In particular, the Luoyang shovel changed its shape to make the top large and the bottom small, so that the shovel could be inserted into the soil and bring it out in a column. When the pit wall is separated from the cut body, the cut body is first fixed with a border and wrapped in film to moisturise it. When the bottom of the pit is cut out, an area is hollowed out with an L-shaped steel "digging spoon" and a load-bearing plank is inserted. When the bottom of the cutter has been completely hollowed out, it has been put into a special box.

On the afternoon of 4 March, the final lifting moment for the second area of pit 5's cutting body. Under the jacking support, the staff welded the outer frame angles and completed the "packing"; water sprayers were on hand to spray the welded joints to avoid igniting the wood due to the high humidity generated when welding the steel frame on site. With the rotation of a small manual gantry hoist, the pit body of Pit 5 slowly emerged from the pit.

"We completed this pit relocation exactly as the archaeologists had requested." When the pit body of Pit 5 was successfully moved out of the archaeological area, Ren Junfeng was already sweating when he took off his protective clothing, "Our scientific construction ensured that the cut body did not collapse and break, and did not damage the pit wall at all, preserving the original information from the excavation by the ancients."

INTENTION

Lab archaeology reveals more unknown things

The gold mask found in Sanxingdui Pit5has amazed the whole country. However, according to the archaeologists, only 20 percent of the excavation at Pit5has been completed, and much work remains to be done in the laboratory.

After the Pit5cut was moved out of the pit, the Staff responsible for cultural relics protection quickly sent it to Sanxingdui Museum cultural protection Center. Archaeological excavations will be carried out here in the future.

Apart from a large number of scattered pieces of gold leaf and ivory carving, the gold leaf, which was exposed in March last year, and the newly discovered "axe-shaped gold ware" are still lying in the soil intact, Li said. "Axe-shaped gold ware", the largest gold ware found in no. 5 pit after the gold mask, the overall shape is like an axe, with a curved blade at the front and several regular grooves on the surface. Compared with most of the previous gold wares unearthed in Sanxingdui, the biggest characteristic of this axe-shaped gold ware is its thickness, with the thickest place exceeding 3 mm. When it first emerged last year, experts speculated it might be a tomahawk that symbolizes power based on its shape. If it was a golden tomahawk, it would, along with the mask, be a sign of their owner’s superior status.

Li Haichao said, if you do archaeology on site, you can only look from top to bottom, and you can only look with the naked eye, even if you use a microscope, the result is not good. After moving it to the laboratory, the equipment used will be much more. "We're going to take the pieces layer by layer. We're going to do ultra-high precision scanning at each layer or we're going to use CT, X-ray, to record all the little pieces. Soil samples are also taken for detailed chemical analysis to see if there are any traces of silk." The excavation of the Pit5may take up to a year.

Journalist: Wu XiaoLing Photographer: Xiang Yu

Editor: Tang Musha, Zeng Ailin