What Bronze Age Brits used for jewelry
|A Stone Age burial dating from 5000-7000 BC shows |
the skeletons of two women who were buried wearing
necklaces made of numerous shells.
The research team used amino acid racemisation analysis (a technique used previously mainly for dating artifacts), light microscopy, scanning electron microscopy and Raman spectroscopy, to identify the raw materials used to make beads in a complex necklace discovered at an Early Bronze Age burial site at Great Cornard in Suffolk, UK.
They discovered that Bronze Age craftspeople used species like dog whelk and tusk shells, both of which were likely to have been sourced and worked locally, to fashion tiny disc-shaped beads in the necklace.
About Tusk Shells
Tusk shells (left) or Scaphopoda, meaning literally "boat-footed" are a class of shelled marine mollusks. Shells range from about 0.5 to 15 cm in length. These mollusks live on soft substrates offshore (usually not intertidally). Because of this subtidal habitat and the small size of most species, many beachcombers are unfamiliar with them; their shells are usually not nearly as common or as easily visible in the beach drift as the shells of sea snails and clams.
The shells of scaphopods are conical and curved and they are usually whitish in color. Because of these characteristics, the shell somewhat resembles a miniature elephant's tusk, hence the common name tusk shell. However, unlike an elephant's tusk, the shells of these molluscs are hollow and open at both ends.
About the Dog Whelk
The dog whelk, dogwhelk, or Atlantic dogwinkle, scientific name Nucella lapillus, is a species of predatory sea snail, a carnivorous marine gastropod mollusc in the family Muricidae, the rock snails.
This species is found around the coasts of Europe and in the northern west Atlantic coast of North America. It is also can be found in estuarine waters along the Atlantic coasts. This species prefers rocky shores, where it eats mussels and acorn barnacles
The researchers included archaeologists, mathematicians, chemists and physicists, the latter from the BioArCh and York Centre for Complex Systems Analysis (YCCSA) and the Departments of Archaeology, Mathematics, Chemistry and Physics at the University of York. Dr Sonia O'Connor, of the University of Bradford's Department of Archaeological Sciences, carried out the light and electron microscopy, and prehistoric jewellery specialist Dr Alison Sheridan, of National Museums Scotland, facilitated access to the Great Cornard necklace, which had been excavated by Suffolk Archaeology.
When it was first established that the tiny white beads had been made from shell, the question arose as to its source. Had the shell been obtained locally or did it originate from a species from further afield, perhaps even the Mediterranean thorny oyster (Spondylus)? The Mediterranean thorny oyster is a shell of long-standing symbolic and cultural significance which is known to have been used on the Continent around the time when the Great Cornard necklace was made.
But this collaborative research, led by Dr Beatrice Demarchi, of York's Department of Archaeology and BioArCh, and Dr Julie Wilson, of the Departments of Chemistry and Mathematics and YCCSA, has shown this not to be the case, and has suggested an alternative possibility.
Dr Demarchi said: "Dog whelks and tusk shells were likely to be available locally so these people did not have to travel far to get hold of the raw materials for their beads.
"There is evidence, from elsewhere in Britain and further afield, for the use of tusk shells at various times in the past. This may well be because they are relatively easy to work and their hollow shape is very distinctive."
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Story Source: Materials provided by University of York. Beatrice Demarchi, Sonia O'Connor, Andre de Lima Ponzoni, Raquel de Almeida Rocha Ponzoni, Alison Sheridan, Kirsty Penkman, Y. Hancock, Julie Wilson. An Integrated Approach to the Taxonomic Identification of Prehistoric Shell Ornaments. PLoS ONE, 2014.