A Mortar-like Sealant Layer in a Bronze Age Burial Mound at Clogher Lower, Co. Roscommon, Ireland

Abstract

Constructional materials and chemical analyses of layers exposed in the cross section of a Bronze Age burial mound are described. X-ray fluorescence comparison of the chemical composition of topsoils from the land surrounding the mound, the topsoil sculpting the mound, and a calcium carbonate-rich layer above the mound's boulder core reveal differences in CaO/SiO 2ratios and concentrations of the trace elements titanium and zirconium. Laboratory tests suggest that the calcium carbonate-rich layer may be a mixture of fired and slaked lake marl and esker sand used as a sealant for the boulder core in the construction of the mound.