The use of geoarchaeological methods to delineate space dynamics and formation processes at settlement site in a forested area, East Lithuania

The region of eastern Lithuania in the Iron Age (I st. mill. AD) is an area with very frequent occurrence of barrow cemeteries of different size, ranging from one to tens and hundreds of mounds. On the contrary, the number of known settlement sites is very low. So far the settlement research has been very fragmented and limited to small-scale excavation producing small and biased samples. Little is known not only how these rural settlements looked like during their existence, but even how they currently look like in the archaeological context. As a result there is no clear answer how compatible are settlement sites and their adjacent burial sites not only in a paleodemographical sense, but also in terms of their chronology.

Archaeological legacy of prehistoric rural communities represents complex of different kind of objects and sites, and those assigned to the same community were expected to survive the same life-history. The connectedness between past human activities and archaeological legacy is, however, by no means straightforward and often difficult to interpret due to combined effect of natural variations in background geology, archaeological context forming processes, symbolic and methodological factors.

My research attempts to contribute to the issue of methodology for estimating lifehistory of settlement, which was recently discovered adjacent to one of the largest barrow cemetery in eastern Lithuania, in several aspects. The first aspect is directed towards the issue of dynamics of spatial use of site. The forested environment of the site limited the range of potential methods (e.g., surface survey or systematic magnetometry). Therefore, the strategy of manual augering across site was chosen and geo-archaeological research was carried out. Especially the magnetic susceptibility (MS) analyses have been vital on this stage of research, but measurement of phosphate (P) and organic soil contents (OM) analyses have also been made (with a discussion on the possibilities and limitations of these methodological approaches). Anomalous MS enhancements have been recorded at several spots of the habitation site and small trenches excavated at these spots revealed burning-related evidences which proved the efficiency of the MS method basically. Moreover, the excavations have shown that anomalies depicted on the MS isoline layout were not contemporaneous with the adjacent barow cemetery, that suggests new perspective for interpretation of the data when correlations between the settlements and the respective burial monuments are to be considered.

Neither the thickness of the cultural layer, nor its very presence was the main cause of MS enhancements, which most likely indicated habitation zones, that appeared to be older than burial site nearby. Accumulated at the spot of natural depression we also have a cultural layer, thick enough although unstratified with mixed artefacts of 5/6-11th centuries, i.e. contemporaneous to barrow cemetery. The cultural layer was bulk sampled each two cm and the soil properties (MS, OM, P, texture) were determined to be rather uniform along the profile, that implies either conditions for sedimentation were stable and consistent, and the input was uniform over 600 years, or the fact that sedimentation occurred in a single episode due to activity after the settlement has been abandoned. Facing indeterminate scenarios for settlement history the future research strategies need to be adjusted to consider short-term changes at the micro-scale (e.g. thin-section micromorphology), that might contributed to the understanding of the rural sites development and the importance of agricultural activities.

This research was conducted as a part of scientific project “Geoarchaeological soil research as a means to investigate ancient settlement sites” financed by Lithuanian Scientific Board (MIP 101/2015) (2015-2017).