Provenance of the gold of the Early Bronze Age Nebra Sky Disk, central Germany: geochemical characterization of natural gold from Cornwall
Ehser, Anja; Borg, Gregor; Pernicka, Ernst
European Journal of Mineralogy Volume 23 Number 6 (2011), p. 895 - 910
published: Dec 1, 2011
ArtNo. ESP147052306006, Price: 29.00 €
The Early Bronze Age Nebra Sky Disk, central Germany, comprises different types of gold inlays which have been plated and punched onto a bronze disk in three phases. The present study aims at provenancing the gold, used for the first phase, which includes gold sheets in the shape of a sun or full moon, a crescent-shaped moon, and 32 stars. The geochemical composition, determined by LA-ICP-MS, of one fragment of the sun sheet is compared with 66 native gold particles from six placer deposits and one lode gold deposit in Cornwall. The focus on Cornish gold deposits is based on results of previous provenance and tin isotope studies. The geochemical survey is performed using distinctive geochemical tracers (e.g., Co, Ni, Cu, Ru, Pd, Ag, Sn, Sb, Ir, and Pt) which are characterized by high stability during geological and metallurgical processes. For Cornwall, the Carnon gold placers at the localities Devoran and Feock show different variations in Co, Ni, Pd, Ag, Sn, and Sb which correlate with the variation found in the gold from the sun sheet when mixed. This mixture would have been easily possible as both localities are located about three km apart from each other. Similar geochemical comparisons with natural gold from central and southeastern Europe, carried out in a previous provenance study, showed no similarity with the sun sheet. Differences in Cu and Pt contents between the Carnon gold placers and the sun sheet, which have also been detected for the previously studied gold deposits, question the relevance of mineral (micro) inclusions and accretions or unintended contamination with heavy minerals during processing. The results on the gold further led to the comparison of 18 Cornish copper ores with the bronze of the Nebra hoard using lead isotope ratios, which showed no correlation, excluding Cornwall as copper source. With the gold of the first phase of the Nebra Sky Disk being likely to originate from Cornwall, substantial metal trade from the British Isles towards central Germany during the Early Bronze Age must be assumed.