Multi-element analysis conducted on soils at Duallin township, Ben Lawers, has highlighted the potential of geochemistry to identify new sites of post-medieval activity across the region (Abrahams et al 2010). When subjected to discriminant analysis, the evaluation of soils by x-ray fluorescence spectrometry (XRFS) revealed significant differences in the chemical composition of soils collected from areas of settlement and arable agriculture. It suggests such areas can be identified according to their chemical signatures. Given the elusive nature of settlement prior to the early 18th century, further applications are likely to be particularly effective in identifying locations where the surface remains of perishable turf dwellings are no longer visible.
Geoarchaeological soil survey conducted across the remains of turf banks and enclosures in Glen Devon was undertaken in an attempt to infer functions of the enclosures. There was no evidence for tillage disrupting soil profiles or for cultivation-induced soil erosion and accumulation and it was thus concluded that the enclosures were likely built for managing livestock (Murray 2007). Micromorphology, integrated in the Ben Lawers Historic Landscape Project, has also permitted commentary on the intensity and possible seasonality of occupation (Simpson and McKenzie 2016c).
The anthropogenic deepening of soil for agriculture is a widely recognised practice across Scotland and geoarchaeological investigations have identified these soils and interpreted them with reference to both rural and urban settlement evidence (Carter 2001). Combined geoarchaeological and historical studies of manuring practices across Scotland have been undertaken by Mackenzie (2006) and Oram (2011). Mackenzie uses soil survey records as both a direct and indirect indicator for the location of deep anthropogenic topsoils. Both studies reference documentary evidence from Perth and its rural hinterland from the late 1600s onwards, evidencing varying practices of manuring across the region. In Perth, waste was gathered into a central midden for licensed waste collection and transported to farms up to 15km away. Despite extensive documentary evidence, neither study involved fieldwork within the region. Deep organic soils overlying organic midden material has been recorded across Perth (Bowler et al 1995; Coleman 1996, 2004; Bowler 2004; Perry and Coleman 2016). These deep organic soils are complex deposits which contain remains of occupation. Better understanding of their nature, development and distribution through detailed micromorphological analysis and extension of initial mapping undertaken by Bowler (2004, 52) could increase our understanding of the growth and development of Perth and its rural hinterland.
Though still limited in application, a significant proportion of geoarchaeological analysis in Perth and Kinross has been conducted on its late post-medieval and early modern remains.
Abandoned rural townships, such as Balnreich and Tombreck, have provided a particular focus for multi-element analysis. Studies have assessed past manuring practices (Davidson et al 2007), patterns of elemental enhancement across functional areas (Wilson et al 2005), the site specificity of soil elemental signatures (Wilson et al 2009), and comparability between sites (Wilson et al 2008). There has also been a comparison of analytical methodologies (Entwistle and Wilson 2007). The identification of distinct elemental signatures for infield/outfield systems has significant implications for the prospection of similar sites in the region, particularly in locations where perishable turf materials have been used and no surface remains survive. Future work should look to build upon and exploit this foundational body of research. Micromorphology, integrated in the Ben Lawers Historic Landscape Project, has also aided the identification and characterisation of occupation surfaces at Tombreck (Simpson and McKenzie 2016d). Whilst commercial studies have used the technique to characterise the formation of field dykes (MacGregor and Crystall 1999).