This week, a treasure trove at the high-profile Sanxingdui archaeological site in Sichuan Province, China, has been unveiled to the public with a total of nearly 13,000 numbered relics unearthed, including 3,155 relatively intact relics in the newly discovered six sacrificial pits. Scantech’s high-precision 3D laser scanners have been used for recording and restoring ancient artifacts unearthed.
Sanxingdui, an ancient site located in Guanghan in Sichuan Province, has been recognized as one of the most important ancient sites in the world for its vast size and long period, and enriched cultural contents.
From the end of 2020 until now, archaeologists have been seeking to uncover the mystery of this ancient civilization by adopting a brand-new archaeological research mode.
By leveraging expertise across different disciplines and fields, they have confirmed that the site is dated to 3000 years ago, showing that the ancient Shu civilization is an integral part of Chinese civilization.
On-site 3D Scanning for Relics Excavated
High-tech methods for archaeology has been adopted to bring the charm of these treasure back to the public, among which 3D scanning plays an important role. Scantech is glad to be a joint force representing the world’s fine craftsmanship and ingenious design.
Repair of a Bronze Sacred Tree
The object to be repaired is the bronze sacred tree No.3, one of eight magnificent trees unearthed from sacrificial pit No.2 of Sanxingdui in 1986.
There is no definite conclusion about the function of the tree. Some think it is related to a kind of tree described in Classic of Mountains and Seas, a Chinese classic text, and a compilation of mythic geography and beasts.
Ancestors of the ancient kingdom of Shu used these sacred trees to communicate with heaven and earth and show their reverence and awe for their ancestors and gods.
Challenge of Replicating Artifacts in Broken State
Unlike the relatively intact and delicate artifacts displayed in a museum, relics excavated in these sacrificial pits were broken and crushed. Evidence suggests that the objects were shattered and thrown into pits after being used for ceremonial rites.
Being severely crushed, most of the relics excavated from the sacrificial pit of Sanxingdui were broken into hundreds of pieces, making them challenging to restore.
In addition, thousands of years of oxidation and decay make the repair even harder. Undoubtedly, the conditions of these artifacts posed great challenges for excavation and restoration.
Given the enormous amount of bronze pieces, it was difficult and time-consuming for researchers to replicate all these broken artifacts with their bare hands, which is a long-standing problem for archaeology.
It took more than ten years for archaeologists to repair sacred trees No.1 and No.2. Recently, the repair of sacred tree No.3 has ended.
Workflow of Reconstruction
Before conducting any restoration for scared tree No.3, the archaeological researchers decided to assemble these pieces to see what they looked like virtually. The decision was to ensure that there is no damage caused to the object before actual restoration and to accelerate the repair process.
The first step was to collect data. Traditionally, experts use conventional measurement methods and photography to record data, which takes a long time. The data captured are usually not complete and limited for use.
This time, for Sacred Tree No.3, archaeologists used 3D scanning to capture the tree’s data. They used our handheld laser 3D scanner to capture the data of 69 branches of the tree one by one.
Thanks to its ultra-high scanning rate, Scantech’s metrology 3D laser scanner assisted researchers in accurately obtaining complete 3D data of relic fragments in a short amount of time.
A model is then generated in 3D software to reconstruct 1:1-sized branches. The 3D model was virtually assembled by referring to similar relics of Sanxingdui from the same period.
Virtual assembly can help to replicate the divine tree No.3 to its original form digitally without damaging it before the actual repair.
It simulates the repair process by virtually assembling these pieces, providing accurate data for shedding insights on subsequent reconstruction. The data captured were also stored and can be archived for further use.