Geochemistry as an aid in archaeological prospection and site interpretation: current issues and research directions

Abstract

Human habitation may significantly affect the chemical soil composition leading to enrichments and depletions of specific chemical elements and the formation of archaeological soils. Prospection and interpretation of sitesby means of element analysis of soils requires appropriate and well-tested geochemical methodologies. In this paper element analysis in archaeological prospection and site interpretation is briefly reviewed and three major unresolved issues are discussed: (i) how to distinguish archaeological chemical signals in soils from modern and geogenic signals; (ii) what role do geochemical processes play in the formation of archaeological soils; (iii) how to implement geochemical methods in archaeological research programmes.These issues are addressed with reference to the geochemical literature on retention and sequestration pathways of presumed anthropogenic elements in soils and analytical procedures. Based on the acquired knowledge, several directions for future research are proposed.

It's Elemental! A Case Study in the Use of Multi-element Geochemical Analysis as an Aid in Locating Cultural Features at the Foundation Site

“…The opposite correlation has been observed in acidic, poorly-drained, hydric soils (Gall et al 2014). The reduction of P in microenvironmental conditions similar to that of the Foundation site highlights the necessity to examine and combine P-data interpretation with that of additional elements, such as Ca, Cu, Fe, Mn, and Zn (Middleton and Price 1996;Parnell, Terry, and Nelson 2002;Terry et al 2004;Cook et al 2006: 629;Holliday and Gartner 2007: 307;Wilson, Davidson, and Cresser 2008: 412-421;Oonk, Slomp, and Huisman 2009;Milek and Roberts 2013).…”

“…Archaeologists have since expanded geochemical investigations to include anthropogenic multi-element chemical residue analyses and have identified close correlations between element suites and past occupation activities. Multi-element chemical residue analysis has ultimately proven successful as an archaeological prospection and interpretive tool to detect, delineate, and interpret broad activities within archaeological sites and to differentiate among discrete activity areas (Deetz and Dethlefsen 1963: 242-243;Cook and Heizer 1965;Eidt 1977;Middleton and Price 1996: 673-687;Wells et al 2000: 450;Parnell, Terry, and Nelson 2002;Middleton 2004;Sarris et al 2004;Cook et al 2006;Wilson, Davidson, and Cresser 2008: 412-424;Oonk, Slomp, and Huisman 2009;Salisbury 2012Salisbury , 2013Milek and Roberts 2013: 1,845-1,865).…”

“…This cost-effective and time-efficient, two-step method involves the application of a weak or moderately weak-acid chemical extraction solution, such as a Mehlich-3 mixed reagent, to separate element cation bonds in dried soil samples. In the second step, extracted elements in the solution are quantified using inductively coupled plasma (ICP) spectrometry (Parnell, Terry, and Nelson 2002;Oonk, Slomp, and Huisman 2009).…”

Impact of microtopography on the geochemistry of soils within archaeological sites in SE Poland

“…Generally, it is based on the assumption that human settlement and activities are reflected in the geochemical record (Lambert 1998;Oonk et al 2009). The most frequently used elements in such studies are P, Ca, K, Na and Mg as well as trace metals such as Cd, Cr, Cu, Pb and Zn (Lutz 1951;Aston et al 1998;Schlezinger and Howes 2000;Wells et al 2000;Terry et al 2004;Oonk et al 2009;Cabala et al 2012;Tian et al 2012). Most of the studies were primarily concerned with the horizontal variation in the content of the studied elements within the archaeological sites (Entwisle et al 2000;Parnell et al 2002).…”

“…Eroded material is accumulated within depressions and at the foot of slopes as colluvia. As such, microtopography and erosion provides yet another challenge for using geochemical prospection in archaeology, alongside the problems indicated by Oonk et al (2009) such as the lack of a unified methodological approach, an accurate determination of the geochemical background, and a thorough understanding of the natural geochemical processes occurring in archaeological sites. This study attempts to assess the impact of microtopography on the distribution of Cd, Cu, P, Pb and Zn content in the soil and colluvial profiles obtained within three archaeological sites in SE Poland.…”