What does the organic chemistry of botanical remains contribute to our archaeological knowledge?
March 27th, 2006
On May 3, 2006 I will be giving a talk at the International Symposium on Archaeometry at 9.15 AM in the Biomaterials session. The talk will be about my current PhD study on the degradation of botanical remains. The program of this symposium sure looks very interesting.
Abstract for the talk
What does the organic chemistry of botanical remains contribute to our archaeological knowledge?
The study presented here concentrates on the preservation of botanical remains, an important component of many archaeological sites. An effort was made to identify the variety in the organic geochemical composition of botanical remains, most often seeds, found at water logged archaeological excavation sites.
The objective of this work is to develop an assessment system for the preservation potential of sites in wetland areas by identifying the correlation between soil conditions and loss/preservation of chemical information in the botanical remains. This correlation can be used to predict whether archaeological resources are threatened by anthropogenic activities.
Various botanical species and remnants of archaeological interest originating from several sources were analyzed to obtain insight in the diagenetic chemical pathway and natural variations in resistance to degradation. The analyses were performed using Py-GC/MS. Identification and quantification of components that react upon decomposition allowed for the derivation of a decomposition scale based on the observed changes. The main components in degraded seeds are derived from lignin, and to a lesser extent, cellulose, although other compounds were encountered too. Using thermochemolysis an alternative look at the composition of the relative abundant lignin compounds was obtained.
In this presentation the first relations observed between the differences in chemistry, degradation state, species and soil conditions will be presented. For example, the formation of 1,2-benzenediols and the loss of 2,6-dimethoxyphenols are indicative for a higher state of degradation. Statistical analyses were applied to justify the correlations.
Also, some plant species produce remarkable chemical fingerprints, which allow recognition even when macroscopic identification is no longer possible. The development of this knowledge by organic geochemists provides archaeologists with an extra technique in their toolbox to obtain more information from a site than is possible nowadays.
Btw, don’t forget to also check out the talk by my colleague Stijn Oonk and the poster by my colleague Lisette Kootker.