Differentiation of Late Bronze Age Nubian- and Egyptian-style ceramics from northern Sudan by manufacturing firing temperatures using Raman spectroscopy

Abstract

Ceramic samples of Nubian and Egyptian traditions dating to the 18th Dynasty of the New Kingdom period (1550–1290 BCE) from the ancient temple towns of Sai Island and Dukki Gel were analyzed using optical light microscopy and micro-Raman spectroscopy to identify the relative maximum firing temperatures reached during their manufacturing process. Our data demonstrate that Egyptian-style ceramics experienced slightly higher maximum firing temperatures than Nubian-style ceramics based on measurements of carbonized plant residues and sub-µm-scale carbon within the matrices, which were likely added as ash to temper the clay. Although no absolute values can be given for the different traditions, maximum firing temperatures likely ranged from 700 °C to 800 °C. Alteration due to oxidative weathering over time after the deposition of the ceramics affected all samples, although more so the specimens from Dukki Gel than from Sai Island. Raman spectroscopy gives new insights to characterize firing conditions during Nubian and Egyptian ceramics manufacture, especially when using a 532 nm measuring laser wavelength on sub-µm-scale carbon within the matrix.