4.2 Charcoal Assessment

by Isabel Figueiral *

4.2.1 Quantity of material and assessment methods

This assessment is based on the examination of some of the larger charcoal fragments (>2mm) selected from a sample of the flots produced on site and extracted by Wendy Carruthers.

Due to time limits (2 weeks), it was not possible to scan the majority of samples. The identification of charcoal fragments is time-consuming because the examination of at least two of the three wood anatomical planes is usually required. The identifications were carried out with a compound microscope using reflected light, and sometimes required comparison with material from a charcoal reference collection.

It was clear, from initial observations of the sample bags, that some samples can be considered exceptional in terms of quantity of charcoal fragments (this is so in the case of Area 11BC). As it would be impossible to scan all the samples available economically, a selection was made to detect:

The number of fragments identified varied from sample to sample (during the identification process charcoal fragments are not selected by size or shape).

In some samples all the fragments available were examined. In several others only the first 25 fragments were identified, thus providing a comparative scale of identified taxa. In the samples with high quantities of charcoals, the number of fragments examined ranged between 50 and 75.

4.2.2 Areas selected

Samples from 15 areas were selected for assessment - AA, AB, BA, BB, BC, BD, BF, CB, CC, CD, CE, DA, DB, DC, DD. The list of the samples studied (or partially) is presented in Fig. 00.

4.2.3 Identification

The quantitative results are not presented here, as the aim of this assessment is to outline the potential of the material for more complete analysis. Therefore the ecological and/or ethnological implications of the different species will not be referred to in detail at this stage. The information summarised in Table 00 is presented in terms of presence and predominance of taxa in the distinct areas of the site. Quantitative results (identified charcoals) of each sample are kept in the archive. We should emphasise that no monospecific samples were found. The number of taxa per sample varied between 2 and 12; per area the number varies between 3 and 16.

The anatomical observation of 929 fragments of charcoal allowed us to distinguish 19 taxa (Table 4.2). Some doubts concerning the identifications are noted. When we are sure about the genus but unable to identify the species, only the genus is stated followed by 'sp.' (e.g. Cornus sp.). In the case of species with very similar anatomical characteristics, requiring a much greater number of fragments for a convincing distinction a 'cf.' is placed before the species name: eg Prunus cf. Prunus avium. The impossibility of distinguishing the different species of deciduous oak obliges us to refer to Quercus (deciduous).

Scientific names Common names
Acer campestre Maple
Alnus glutinosa Alder
Betula sp. Birch
Calluna vulgaris Heather
Corylus avellana Hazel
Cornus sp. (Dogwood/Cornelian Cherry Dwarf Cornel)
Fraxinus excelsior Ash
Ilex aquifolium Holly
Prunus cf. P. avium P. cf. Wild cherry
Prunus cf. P. padus P. cf. Bird cherry
Prunus spinosa Sloe, Blackthorn
Prunus sp.
Quercus (deciduous) Oak
Rosaceae Pomoidea Rosacea
Ros. cf. Crataegus monogyna Rosacea cf. Hawthorn
Ros. cf. Pyrus/Malus Rosacea cf. Pear/Apple tree
Salix sp. Willow
Sambucus nigra Elder
Ulex sp. Gorse
Table 4.2 Charcoal: principal taxa present

This floral list is composed of species characterising different ecological habits. Some of them are among the most common woodland trees recorded in the Middle Ages and in the Anglo-Saxon charters, including oak, ash, hazel, maple and hawthorn. Alder, birch and holly are also recorded, although very rarely (Rackham 1980).

A glance at the overall results makes it clear that oak and hazel are the only two taxa identified in almost all areas. In fact oak is absent only from Area BF while hazel is absent from Area BB. Oak is also the predominant taxon in eight of the fifteen areas. However, this does not mean that this species is particularly important throughout the samples. Oak was not identified in six of the samples and even when it is the predominant taxon this does not imply that it dominates all others. In fact the number of fragments so far examined is too small (in proportion to the total number available) to give us representative results.

Fragments belonging to the Rosaceae are particularly problematic in identification. Anatomical characteristics of the different species are very similar and the variability of wood makes it difficult to distinguish between the species with certainty. Concerning the genus Prunus, we note that although the species Prunus spinosa (Sloe) presents no great problem of identification the species Prunus avium (Wild Cherry) and Prunus padus (Bird Cherry) can be easily confused. The anatomical characteristics of Prunus padus are also very close to those of Prunus domestica var. insititia (Bullace). Only the identification of a greater number of fragments of the different species and a careful comparison of the wood variabilities with reference material will make it possible to establish the exact number of fruit tree species present at the site.

It was impossible to distinguish between the genus Pyrus (pear) and Malus (apple), although some of the characters observed might be closer to those of Pyrus. Pear is, in fact, one of the six commonest trees in the Saxon Charters (Rackham 1980).

These results accord with those of Wendy Carruthers: probable Prunus stones were found amongst the mineralised material. Charred hazelnut shells seem to be common around the site (see 4.1 Plant Macrofossils). It is possible therefore, that the abundance of fruit trees might be connected with some kind of orchard cultivation. This hypothesis can only be confirmed, or not, through more extensive analysis and by the observation and correlation of the annual rings.

The identification of Calluna vulgaris (heather) is also common to both the charcoal and plant macrofossil analyses. The identification of this particular species here seems particularly interesting. Its presence (as well as that of gorse) indicates:

The reasons behind the selection of these two vegetal elements might be made clearer by further studies, which will pinpoint the specific areas where they appear and then relate them to the associated archaeological material.

The collection of heather seems to have been carried out all year long. In fact some of the twigs were complete and allowed us to note that they were cut both inside and outside the growing season. However, more comparative results are needed, as the number of fragments in question is very small.

4.2.4 Additional data

The excavations undertaken in 1995 have yielded a further 500 charcoal samples relating to domestic, craft and possibly ritual activity from the Late Roman and Early to Middle Saxon deposits. The better stratigraphic data from these areas, coupled with the presence of a number of deposits closely related to major features such as the bread ovens examined in Area 12AF, offer an improved potential for the study of functionally dependent consumption.

4.2.5 Preservation

The material studied was well preserved. All the necessary anatomical characteristics were present in most of the fragments. Only in a few fragments (25) was it impossible to achieve an identification due to poor preservation.

4.2.6 Assessment of the potential for analysis Flora and vegetation

Reliable results in charcoal analysis depend on the identification of the greatest number of fragments possible (taxonomic curves are plotted for each sample) from the largest possible area, in order to obtain a reliable statistical basis to interpret the results not only in terms of the flora (species present) but also in terms of vegetation (abundance of each species and its relationship with the others). The high level of sampling of ecofactual material from this site makes it possible to carry out such research. The analysis of a greater number of charcoal fragments will, most probably, enlarge the floral spectrum already obtained, as the rarer species will occur in larger samples (see also Reconstruct the environment and economy of the settlement). Timber as a raw material

The study of data thus obtained will also make it possible to draw the ethnological background pinpointing specific selection of wood either as fuel (for domestic or industrial purposes), or as material for building, thatching and bedding, making domestic instruments, or even as fodder, stable-litter and agricultural manure (see also 3.6.1 Post-Hole structures, 3.6.2 The Grubenhäuser and Explore the architecture of the settlement). Land-use and exploitation

Further analysis will provide complete data on the exploitation of distinct ecological territories, including how they were used and for what purpose, which should prove particularly interesting (see also 7.1.2 Roman and Reconstruct the environment and economy of the settlement). Seasonality

It is possible that some samples will provide larger numbers of complete branches or twigs, enabling us to determine during which season they were cut and therefore identify seasonal trends in the collecting of certain species. Woodland management

It was observed that in some branches of hazel the last annual rings were very close together, which means that their growth had been slowed down. It is likely that this feature might be connected with some form of management of wood-producing trees: coppicing and/or pollarding. However, only further analysis will provide reliable data on the existence or otherwise of managed woodlands (see also Reconstruct the environment and economy of the settlement). Inter- and intra-site comparison

Interdisciplinary work will be fundamental to achieve full understanding of our results (comparative data from pollen analysis and plant macrofossils will be particularly important). The comparison of the charcoal results both across the West Heslerton site and with those from other contemporary sites in Britain, in particular, and elsewhere in west and central Europe will be indispensable.

4.2.7 Storage and curation

Relatively little space is needed for the storage of charcoal. The fragments in excess of the amount needed for analysis are kept in the plastic bags, which in turn are stored in a plastic or cardboard container to avoid accidental breakage. Charcoal fragments under analysis are stored in labelled envelopes (in each sample fragments from different species are separated into different envelopes) which are sealed and stored in cardboard boxes.

4.2.8 Conclusion

The sampling strategy followed on site has made it possible to carry out an exemplary programme of research on environmental archaeology. We believe that the opportunity of fully understanding the interactions between man and his environment at this particular epoch can not, and should not be missed.


© Internet Archaeology URL:
Last updated: Tue Dec 15 1998