Tracing the past from the analysis of Cu, Zn, Mn, Sr, and Rb in Archaeological Dark Earth soils from the tropics and temperate zone

Abstract

The analysis of minor/microelements in anthropogenic soils resulting from past settlement activities in different environmental conditions and geographical regions is not well-known. The study aimed to determine whether minor/microelements are suitable proxy indicators of past human activities of Archaeological Dark Earth (ADE) soils from two past hilltop settlements- Ziavi-Galenkuito in Ghana and Dřevíč hillfort, Czech Republic. Total and plant-available (Mehlich 3) contents of minor/microelements were determined using portable X-Ray Fluorescence spectrometry and Inductively coupled plasma mass spectrometry, respectively. The black color of the soils from Ziavi-Galenkuito and Dřevíč hillfort contrasted the brownish Ferric Acrisol and greyish Luvic Cambisol control, respectively. The contents of total and plant-available Cu, Zn, Mn, Sr, and total Rb was substantially higher in both sites compared to their control of the same geological substrates. The highest total and plant-available Mn content in Ziavi-Galenkuito may indicate specific intensive settlement activities in a comparatively shorter duration. The highest total Cu, Zn, Sr, and Rb content in the soil from Dřevíč hillfort compared to Ziavi-Galenkuito related to longevity and intensity of the past human activities. Total Cu, Zn, Mn, and Sr can well reflect past human activities from different geographical regions according to their significant correlations from both studied sites. Except for Mn and Sr, total and plant-available content of Cu and Zn were not well correlated. Except for Mn and Sr, total and plant-available content of Cu and Zn were not well correlated. In the calculation of enrichment factors in ADE soils for geoarchaeological purposes, total Mn, Cu, Zn, and Sr are more suitable. Enrichment by minor/microelements can be reliable enough in predicting past human activities in ADE soils of different geology and climatic conditions, even after hundreds of years.