Above: Reflected-light micrography of the mineralized cotton fibres (X500) (Copyright C2RMF, C. Moulherat).
Mehrgarh is the gift that keeps on giving to archaeologists, this time as the location with the oldest known cotton in the Indian subcontinent. Pushing back the origin of major crops, like rice recently, or silk previously, suggests that while some agricultural practices may have spread east to the Indus valley, others, like rice and perhaps cotton and crops that could rotate with other crops may have spread westwards from the Indus region. The many river eco-systems would have allowed ample time for experimentation and the perfection of different crop strains.
In this study, several threads preserved by mineralization in a copper bead from a Neolithic burial (6th millennium) at Mehrgarh, Pakistan, were subject to rigorous metallurgical analysis. Under this new microscopic procedure, the fibres were identified as cotton (genus Gossypium).
This article encapsulates several unique aspects with regard to this discovery:
- First, an explanation of the exceptional preservation of cotton fibres which represent a unique find. The preservation "results exclusively from the corrosion process of copper in which metallic salts are liberated and can thus impregnate the organic material. This type of conservation is rare, especially for periods before the ‘‘true’’ metal ages, for which metal objects are extremely scarce."
- Second, that the methodology employed was specially developed by Christophe Moulherat in France for the study of mineralized fibres, demonstrating the potential of this new method for similar material from other sites. This new procedure, combines the use of a reflected-light microscope and a scanning electron microscope to to study the particular morphology of each fibre. The observations allowed the identification of the fibres as cotton, genus Gossypium with several degrees of ripeness among the various Mehrgarh fibres. However, these methods cannot be used to identify the exact (modern) species of the Neolithic cotton fibres due to lack of comparable reference material.
- Finally, this find from Mehrgarh sheds new light on the early history of cotton in the Middle East to allow us to consider an even earlier use of cotton dating to the 6th millennium. The authors state that despite the fact that it is not possible to ascertain whether this cotton thread was derived from an already domesticated species, "it seems clear the cotton as such was already known and exploited for its fibres at this period. The accumulation of evidence of early cotton in Pakistani Balochistan (Mehrgarh, Shahi Tump) and in the Indus Valley seems to confirm the hypothesis of a South Asian origin, probably in the Greater Indus area, of one of the Old World cottons."
From the article:
"Cotton, either in the form of fibres or seeds, has been identified at several other sites in South Asia. Remains of a cotton string, conserved inside a carnelian bead, were found in a 4th millennium grave at Shahi Tump in the Makran division of southern Balochistan (ongoing excavations by the French Archaeological Mission to Makran, preliminary study by Moulherat). So far, no cotton seeds have been recorded from this site (Tengberg, research in progress) but a local origin seems entirely possible. The situation is somewhat different at Dhuweila in eastern Jordan, where fibres and impressions of a woven cotton fabric were also found in a 4th millennium context (Betts et al.,1994). For ecological reasons, the Dhuweila cotton was most likely imported from elsewhere, perhaps from the Indian subcontinent. By the beginning of the 2nd millennium the evidence for both cotton fibres and seeds becomes more frequent, especially in the Indus Valley and Peninsular India. Fragments of a cotton fabric and a piece of cotton string were preserved in contact with a silver vessel at Mohenjo-daro (Gulati & Turner, 1929; Marshall, 1931: 33)." (First Evidence of Cotton at Neolithic Mehrgarh, Pakistan, Journal of Archaeological Science (2002) 29, p. 1399).