Climatic reconstruction using wood charcoal from archaeological sites

This thesis assesses the feasibility of using wood charcoal from archaeological sites as a palaeoclimatic indicator. Three techniques are described: (i) charcoal identification from Xylem Anatomy. (ii) Ecologically Diagnostic Xylem Analysis and (iii) stable carbon isotope analysis on wood charcoal. The first is a well established method of environmental reconstruction. This is the first systematic application of Ecologically Diagnostic Analysis and the first application of stable carbon isotope analysis on wood charcoal. Charcoal identification shows that the most common woody species at Elands Bay today are also evident in the archaeological record over the last 4000 years, indicating a relatively stable plant community composition. Previous studies of wood anatomy have shown that there are links between vessel size, vessel number and climate. This study demonstrates that the wood anatomy of Rhus is not simply related to climatic factors, necessitating the employment of a wide range of statistical analytical techniques to identify climatic signals. In contrast, the anatomy of Diospyros shows strong correlations with temperature. Factor analysis of anatomical parameters of charcoal from Elands Bay archaeological sites indicates that there have been temperature changes over the last 4000 years. Stable carbon isotope ratios (¹³C/¹²C) of plants have been found to be a useful indicator of water use efficiency; plants in drier habitats exhibit more positive values than their more mesic relatives. The results of an isotopic analysis on modern wood charcoal show that ¹³C/¹²C ratios can be related to temperature and rainfall. The climatic component of the range in variation of ¹³C/¹²C in the archaeological record is not as easy to identify due to increased use of fossil fuels since the beginning of the Industrial Revolution. Indications are that wood charcoal does carry a climatic signal. A larger sample from more areas may give more dependable results.

Grantor dc:publisher.institution

Department of Archaeology

Year dc:date.issued

1990

Author dc:creator

• February, Edmund Carl

Advisor dc:contributor.advisor

• Parkington, John

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/19516

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/19516