image/svg+xml17 VIII/1/2017 INTERDISCIPLINARIA ARCHAEOLOGICA NATURAL SCIENCES IN ARCHAEOLOGY homepage: http://www.iansa.eu Tracing Archaeology through Geochemistry: an Example of a Disturbed Prehistoric Hilltop Settlement Site in South-Eastern Lithuania Andra Simniškytė-Strimaitienė a* , Aušra Selskienė b , Jūratė Vaičiūnienė b , Vidas Pakštas b , Ramūnas Šmigelskas a a Lithuanian Institute of History, Kražių g. 5, 01108 Vilnius, Lithuania b Center for Physical Sciences and Technology, Saulėtekio av. 3, 10257 Vilnius, Lithuania 1. Introduction The geoarchaeological research summarized in this paper followed the excavation of a heavily-disturbed Bėčionys hilltop settlement site in south-eastern Lithuania. The archaeological excavation revealed a distribution of subsurface features holding few or no artefacts. According to what was left of them – stains forms, profles, fllings and artefacts (or absence of them) – all these were registered as sunken features, without any attempt of further interpretation of possible function (midden, posthole, hearth, etc. ). The features with artefacts were doubtless worthy of documentation, at least regarding the archaeological value of their infll, whereas objects holding no artefacts lacked any such reason. The overall task, therefore, was to determine any culture-related criteria for these features.Recent studies indicate that an analysis of geochemical and geophysical properties of sediments can contribute towards the detection of human occupation beyond the archaeological remains. This is because anthropogenic activity, including food preparation, freplaces, middenning or craft-working, alters the natural sediments in recognizable ways, forming new soil characteristics that can be traced and measured through multi-analytical methodologies. To date, elevated levels of Ca, P, Cu, Fe, Mg, K, Na, Zn, etc. , have been commonly found in archaeological soils and associated with specifc inputs (Dirix et al. 2013; Entwistle et al. 2000; Hjulstrom, Isaksson 2009; Linderholm 2007; Linderholm, Lundberg 1994; Marwick 2005; Middleton, Price 1996; Middleton 2004; Parnell et al. 2002; Wells 2004; Wilson et al. 2008). However, the establishment of relationships between soil properties and past human activities is by no means straightforward. Ancient soil signatures are site- Volume VIII ● Issue 1/2017 ● Pages 17–33 *Corresponding author. E-mail: andrasimnas@gmail.com ARTICLE INFO Article history: Received: 17 th September 2016Accepted: 25 th April 2017 DOI: http://dx.doi.org/ 10.24916/iansa.2017.1.2 Key words: subsurface featuresarchaeologysoil chemistryXRF analysismagnetic susceptibilityearly 1 st millenium AD ABSTRACT The aim of the research summarized in this paper was to describe soil properties from diferent contexts at an excavated hilltop settlement (subsurface features with artefacts, subsurface features holding no artefacts, and several sets of samples from substratum), to determine possible anthropogenic indicators at this locality, and to assess what, if any, are the diferences of soil properties taken from the features with artefacts and those holding no artefacts. For this aim, 43 bulk soil samples were collected and analyzed for 16 chemical elements, magnetic susceptibility, soil organic matter and inorganic carbon, and pH values. The results revealed several sets of anthropogenic markers, among which the most distinguished were P, Mn, Zn and MS anomalies. A correlation between the presence/absence of artefacts and soil properties has not been detected. Anthropogenic sets were confrmed for almost all features with artefacts and for the major part of features holding no artefacts; thus the altered soil geochemical properties for these features can be assumed as an important additional cultural marker beyond that given by the archaeological remains. A handful of features with artefacts in one of them failed to be recognized as bearing any human-related signal; taking into account the circumstances, with reasonable care, they were categorized as disturbances having no archaeological value. No unambiguous interpretation is suggested for the analyzed subsurface features; rather they were considered in assessing various scenarios of archaeological context formation.
image/svg+xmlIANSA 2017 ● VIII/1 ● 17–33Andra Simniškytė-Strimaitienė, Aušra Selskienė, Jūratė Vaičiūnienė, Vidas Pakštas, Ramūnas Šmigelskas: Tracing Archaeology through Geochemistry: an Example of a Disturbed Prehistoric Hilltop Settlement Site in South-Eastern Lithuania 18 specifc and often difcult to interpret due to the combined efect of natural variations in background geology, soil- forming processes, complexity of site-use history, and methodological factors (Haslam, Tibbett 2004; Oonk et al. 2009a; 2009b; Wilson et al. 2009; López Varela, Dore 2010 ) . It may be the reason for geochemical methodology being neglected in archaeological research projects, especially at disturbed sites.The main idea of this paper is to describe the soil properties from diferent contexts at an excavated hilltop settlement (infll of subsurface features with artefacts, infll of subsurface features without artefacts, and several sets of samples from the substratum) using several geochemical and geophysical techniques. It was assumed that a comparison of these deposits must show what are the possible anthropogenic indicators at this locality, and whether there are any diferences in the properties of soils taken from features with artefacts and those without. Under the circumstances of rescue archaeology, given the time shortages and economic circumstances, artefacts are often the only criterion to determine/deny the archaeological value of an object. This study, therefore, aims to assess if the presence/absence of artefacts is sufcient reason to justify this. It was also assumed that the spatial and functional links of consistent patterns of possible anthropogenic indicators might indicate the contemporariness of (back-) flling processes and/or related inputs. In Lithuania, only a few studies regarding the topic of ancient soil geochemistry for prospecting aims without subsequent excavations to test the collected data have been carried out so far, ( e.g. Stančikaitė et al. 2009; Bliujienė et al. 2012), therefore it was important to assess the advantages and limitations of this technique for excavated sites. 2. Study area and archaeological site2.1 Natural setting of the study area The study was undertaken in a remote rural area adjacent to the village of Bėčionys, Šalčininkai District, south-eastern Lithuania (Figure 1). The area is characterized by a temperate climate with a mean annual temperature of 6.8°C and an average annual precipitation around 700 mm.The site surveyed is located in the western part of the Ashmena Upland (Basalykas 1965; Guobytė 2002). The landscape of the region was formed during the melting of lobes of the penultimate (Medininkai) glaciation (Figure 1). The end moraine formations and carbonated gravel-sandy glaciofuvial ridges have been mapped in the area. The last (Late Nemunas) glacier did not reach this region, but for a long period permafrost conditions prevailed here and the surface was intensively exposed to mechanical decay and