Organic residues in Paleo-artefacts

Introduction
A controversial question is the possibility that organic and biological residues can be found in crevices in paleo-artefacts, and that these can be studied. If this is the case, such studies will provide valuable information on the diet and culture of our ancestors. The ion-microprobe has been used to illuminate this issue. The new aspect of these studies has been the extraction of the residues, for almost background free elemental analysis. Elemental maps of the resdues of plant and other biological material has been obtained.




As an example, the bone tool sample DN 963 is shown from which a plant fiber was extracted.

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The extracted fibre is shown mounted between two ultra-thin sheets of mylar foil

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A close up shows the fibre in the mylar sheets

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The resulting PIXE maps for different elements follow the shape of the fibre

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The red areas a selections for raster scanning to extract quantitative X-ray spectra.

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The elemental analysis was determined ......

Element

Conc ng/cm2

Available

Mg

17.7

?

Al

203.3

Y

Si

833.5

Y

P

59.5

Y

Si

29.6

Y

Cl

101.6

Y

K

257

Y

Ca

264.3

Y

Ti

95.6

Y

Mn

817.8

Y

Fe

2217

Y

Cu

8.4

?

Zn

29.7

?

Rb

45.4

?

Sr

0

N

Zr

0

N


These results have been presented at two Conferences

This initial study sheds tanatalising new light on a controversial area. The ongoing research aims to study a wider set of samples with an improved sample mount system. The samples will also be subjected to DNA analysis. The issue of Diagenessis (alteration of chemistry over time, clearly evident inthese samples) can then be better understood, and perhaps, then, the aims of the staudy may be realised.

These measurements were performed at the Schonland Research Institute for Nuclear Sciences at the Wits University.