Jianbo Guo, Ruochen Ge, Lu Yang and colleagues studied textile residues on objects from the Sanxingdui sacrificial pits K2–K8, the site of the famous bronze heads and gold masks of the ancient Shu culture. They found silk on 101 objects, 94 of them bronzes, dating to the Late Shang period (1300–1046 BCE). Microscopy and infrared tests identify mulberry silk, mostly plain weave, some coloured with hematite or an organic red dye, and some cloths as finely woven as Shang silks from the Central Plains.
Why it matters: Sanxingdui’s strange bronzes, with no writing and no close parallels, are a favourite puzzle. The study shows that silk was used on a large scale in its sacrificial rites, with objects wrapped, covered or laid on cloth before being broken, burned and buried.
Mainstream view: The authors place ancient Shu within the wider Shang-era silk tradition. Spindle whorls hint at local textile work, but there is no direct proof that silk was made at the site.
Alternative view: Sanxingdui has no deciphered or systematic writing. The authors only suggest, as an idea and not a finding, that silk could have been a writing surface that has not survived.
Matthew Waters, Mark Brenner and colleagues dated sediment cores from two lakes beside ancient Maya settlements in the northern Yucatán. Mercury, linked to the Maya use of cinnabar (red pigment) and elemental mercury, exceeded modern sediment toxicity thresholds for centuries between about 40 and 820 CE, peaking around 720 CE at Cenote Xcach. In the same layers, markers for algae, cyanobacteria, ostracods, snails and midge larvae declined or vanished, and recovered when mercury fell.
Kelly Graf, Ted Goebel and colleagues report on Shég’ Xdaltth’í’ (formerly McDonald Creek), 55 km south-southeast of Fairbanks. It has three Late Pleistocene occupation layers dated to about 13,800, 13,000 and 12,700 years ago. The oldest layer holds more than 80,000 specimens, including a distinctive hafted biface, bone and antler tools, animal remains and well-preserved activity areas.
