Implications of burial alterations on luminescence dating of archaeological ceramics

Abstract

Recent mineralogical studies on archaeological pottery samples report significant variations in alkali metal concentrations due to environmental alterations during burial. Here we examine the effects of potassium (K) leaching on luminescence dating. The effect on the estimation of the dose rate is studied by considering four models of leaching (exponential, linear, early and late) and their impact on fineand coarse-grain dating are calculated. The modeling approaches are applied to two cases of pottery in which evidence for alteration was found. Additionally, TL dating performed on pottery of one of the studied cases, indicates the importance of leaching effects on absolute dating measurements.

On the provenance and manufacture of red-slipped fine ware from ancient Cassope (NW Greece): evidence by X-ray analytical methods

“…Severe changes in alkali metals have been correlated with the firing temperature, both in calcareous and non-calcareous pottery. These changes may be manifested either as a loss of alkalis from the sherd or as a concentration gradient between the surface and the core of the sherd (Buxeda i Garrigós, 1999;Buxeda i Garrigós et al, 2001;Picon, 1976;Schwedt et al, 2004Schwedt et al, , 2006Schwedt and Mommsen, 2007;Zacharias et al, 2005). The pattern is attributed to the high mobility of alkalis that are redistributed within the ceramic body upon evaporation of water that forms during thermal dehydroxylation of the clay lattice.…”

Witnessing prehistoric Delphi by luminescence dating

“…SEM images show signs of high-firing effects, especially for samples D7 and D8. The well-documented effect of cation exchange capacity for high-to over-fired calcareous pottery (Buxeda i Garrigos, 1999;Buxeda i Garrigos et al, 2002;Picon, 1976) has been reported in the literature as being responsible for chemical and mineralogical alterations resulting in a significant K leaching (Zacharias et al, 2005); this effect was also detected in cases of medium of even non-calcareous but high-fired pottery fragments (Zacharias et al, 2006a, Zacharias et al, 2006b, similar Table 2). The vitrification is thus advanced, indicating temperatures of around 850-1050 • C (Maniatis and Tite, 1981).…”

Early ceramic trade in Gansu and Qinghai regions, northwest China: A comparative elemental analysis on sherds of Majiayao culture, Yangshao culture and Qijia culture

“…In addition, independent PCAs are carried out including either majorminor elements or trace elements. Considering the possibility of some alteration and contamination process (Buxeda i Garrigós, 1999;Zacharias et al, 2005Zacharias et al, , 2007Hong et al, 2011), calcium (Ca) is out of the PCA analysis. Principal component analysis on the data shows that the first two principal components shown in Fig.…”