reviewed by P.S. Quinn

The application of micropalaeontology to archaeological problems is a very promising area of collaborative science (see Quinn 1997, for a general review). One of the fields in which this has been true is the analysis of micro-fossils from archaeological pottery, where skilled micropalaeontologists have worked with archaeological scientists for some years to address questions pertaining to the provenance and technology of ceramic artefacts. The bulk of this analysis has been carried out in north-western Europe by a handful of scientists studying diatoms and other siliceous micro-fossils isolated from low-fired pottery from the Stone Age to Iron Age (Alhonen and Matiskainen 1980; Alhonen et al. 1980; Jansma 1977, 1981, 1982, 1990; Matiskainen and Alhonen 1984; Håkansson and Hulthén 1986, 1988 etc.). The approach which was pioneered by these authors (see Battarbee 1988, for a review) has been continued by the work of Stilborg, et al. (1997), which demonstrates the current level of information that can be achieved by the study of micro-fossils in ceramics.

Shards of Iron Age Communications is a multidisciplinary study of the internal structure and external contacts in the Gudme-Lundemborg area, Funen, Denmark, during the late Roman Iron Age. In it, Stilborg recruits Hannelore Håkansson to analyse the siliceous micro-fossils contained within certain samples of pottery. Håkansson isolated the diatoms and other siliceous structures by digesting pottery samples in hydrofluoric acid according to the method of Håkansson and Hulthén (1988) and prepared slides from the digested residues according to the procedure described in Håkansson (1982).

The micro-fossils contained within the Iron-Age pottery from the Gudme-Lundemborg area are used in four ways: (1) to group and separate the various pottery samples; (2) to ascertain information pertaining to the nature of the micro-fossiliferous deposits which were procured for the manufacture of some of the pottery; (3) to indicate the likely provenance of some of these raw materials, and (4) to infer details of the ceramic technology used in the manufacturing process.

1. The presence and absence of siliceous and calcareous micro-fossils has been used to group and separate the pottery sherds. Two broad micro-fossiliferous pottery groups were established: the 'D-ware' pottery, so-called because it was found to contain diatoms and other siliceous micro-fossils in thin section; and the 'F-ware' pottery, which contained foraminifera. These fabric groups were found to be mutually exclusive except for one sample, which contained both diatoms and foraminifera.
2. By studying in detail the nature of the siliceous micro-fossils from the D-ware pottery, Stilborg, et al. are able to subdivide this group into those sherds containing exclusively marine or a mixture of marine and non-marine diatoms, those containing exclusively non-marine diatoms, and a sub-group which contains siliceous plant remains and no diatoms. From this subdivision it is possible to ascertain the nature of the various deposits used for the construction of the D-ware pottery. These are a marine clay, a fresh-water clay, and clays indicating brackish water conditions (possibly an estuary) because of their mixture of marine and non-marine diatoms.
3. On a large scale the distinction between marine and non-marine clays (as represented by diatoms) has been used to indicate coastal vs inland provenance (q.v. Jansma 1982). However, a consideration of the local geology can often lead to a more detailed provenance interpretation (e.g. Matiskainen and Alhonen 1984). Stilborg, et al. (1990) were able to infer that the marine clays used in some of the sub-samples of the D-ware pottery could have been procured from anywhere along the coast in this region and therefore could have been collected at Lundemborg, where the pottery was excavated.

   If estuarine clay was in fact used for the samples of D-ware pottery which contained a mixture of marine and non-marine diatoms, then this may also have been procured near Lundemborg, where the Tange stream empties into the sea. The single sample which forms the non-marine subgroup of D-ware pottery was excavated from the inland site of Gudme; there is a large fresh-water lake (Gudme Lake) from which the clay used to construct this vessel is likely to have come. A suitable source of foraminifera-rich marine clay was also found in the Lundemborg area. The F-ware pottery may have been manufactured from this clay.

4. One micro-fossiliferous pottery sherd contained both diatoms and foraminifera. In thin section it can be seen that this sample is made from a mixture of two different clays, which agrees with the results of the micropalaeontological analysis. It is likely that diatomaceous marine clays from the coast at Lundemborg and foraminifera-rich clays from the F-ware deposits nearby were mixed to produce this vessel.

The sort of multidisciplinary approach to material-based archaeology which is presented in this book is very important for the development of the subject and permits the retrieval of data which would otherwise be unavailable. The collaboration between Ole Stilborg and Hannelore Håkansson outlined above highlights this point very well. Micro-fossils can be a common component of much archaeological pottery, and their detailed study by skilled micropalaeontologists has much to offer ceramic petrology, as well as archaeology in general.

Works cited
Alhonen, P., Kokkonen, J., Matiskainen, H. and Vuorinen, A. 1980. Application of AAS and diatom analysis and stylistic studies of Finnish sub-Neolithic pottery. Bulletin of the Geological Survey of Finland 52: 193-206.

Alhonen, P. and Matiskainen, H. 1980. Diatom analysis from prehistoric pottery sherds -- an archaeological evaluation. In Proceedings of the Nordic Meeting of Diatomologists, Lammi, pp. 45-62.

Battarbee, R.W. 1988. The use of diatom analysis in archaeology: a review. Journal of Archaeological Science 15: 621-44.

Håkansson, H. and Hulthén, B. 1986. On the dissolution of pottery for diatom studies. Norwegian Archaeological Review 19(1): 34-8.

Håkansson, H. and Hulthén, B. 1988. Identification of diatoms in Neolithic pottery. Diatom Research 3(1): 39-45.

Håkansson, H. 1982. Taxonomical discussion on four diatom taxa from an ancient lagoon in Spjälkö, South Sweden. In Rapport från diatomésymposium in Lund, maj 1981 (ed. H. Håkansson). University of Lund, Report 22, pp. 65-81.

Jansma, M.J. 1977. Diatom analysis of pottery. In Ex Horreo (eds Beck, B., Brandt, R. and Groemana-van Waaterringe, W.). Amsterdam: Society Ex Horreo, pp. 77-85.

Jansma, M.J. 1981. Diatom Analysis from Coastal Sites in the Netherlands. BAR International Series 94, pp. 145-62.

Jansma, M.J.. 1982. Diatom analysis of prehistoric pottery. In Proceedings of the 7th International Diatom Symposium at Koenigstein (ed. Mann, D.G.), pp. 529-36.

Jansma, M.J.. 1990. Diatoms from a Neolithic excavation on the former island of Schokland, Ijselmeepolders, the Netherlands. Diatom Research 5(2): 301-9.

Matiskainen, H. and Alhonen, P. 1984. Diatoms as indicators of provenance in Finnish sub- Neolithic pottery. Journal of Archaeological Science 11: 147-57.

Quinn, P.S. 1997. Scientific Methods in Underwater Archaeology by Irmeli Vuorela (review). Marine Micropalaeontology 30(4); 346-50.

Copyright © P.S. Quinn 1998