Extended Data Fig. 8: Technological analysis and Raman analysis of the Shiyu disc.
From: Initial Upper Palaeolithic material culture by 45,000 years ago at Shiyu in northern China
a, Raman spectrum (RAM292) of the disc surface showing bands typical of graphite. b, positioning, in red, of quantitative values extracted from the RAM292 spectrum within a metamorphic gradient (modified from Fig. 8 of Beyssac)36, indicating that the carbon material used for the production of the disc was submitted to a medium to high degree of metamorphism. c, drawing summarising results of the disc analysis: 1, areas covered by labels and varnish; 2, areas abraded on a grindstone and smoothed by use wear and curatorial handling; 3, facet abraded on a grindstone; 4, fractures developed following clivage planes of the raw material; 5, surface of the perforation; 6, unmodified surface; 7, striations left by grinding indicating the direction of the grinding motion. d, microscopic analysis of the Shiyu disc.1-4, close-up view of the perforation and surrounding areas with ___location of the micrographs presentedNotice the blunt shiny appearance of the perforation and the palimpsest of randomly oriented striations of different size and length covering the surface, interpreted as resulting from wear and curatorial handling.
