The oldest metal contamination at the foot of the Giza pyramids

A new study has revealed the oldest copper and arsenic contamination on the Giza plateau in Egypt, dating back more than 5,000 years to the foot of the pyramids and resulting from the tools used to build the necropolis. These metals are original tracers that help to resolve uncertainties about the construction of certain pharaonic tombs.

This study is the fruit of an international and interdisciplinary collaboration that has produced several articles on the palaeoenvironmental reconstructions of the Giza plateau, where the pyramids of Cheops, Kephren and Mykerinos were built, as well as numerous pharaonic tombs. While this site has been the subject of a great deal of archaeological work, geomorphological, palaeoecological and geochemical approaches are rare or non-existent. The simultaneous use of these approaches on samples from the same site reveals the oldest regional copper and arsenic contamination, dating back more than 5,000 years, resulting from the use of tools, in particular for the construction of the necropolis.
 
This discovery was made possible by geochemical analyses carried out on a sediment core drilled at the foot of the pyramids, in an ancient branch of the Nile that has now disappeared and was used to transport construction materials, an ancient branch characterised by geophysical and geomorphological prospecting published by the same team (Sheisha et al., 2022; Younes et al., 2024).
 
The different phases in the development of the Giza necropolis can thus be characterised chemically from the Predynastic period to the New Kingdom, with particular attention paid to the construction of the pyramids and the Sphinx. This study confirms archaeological findings and helps to dispel uncertainties about the dates on which Pharaonic tombs were built, particularly during the First Dynasty, more than 3,000 years BC. This work fits in perfectly with previous archaeological discoveries and provides original data that opens up new avenues of research into the necropolises of the Nile Valley, using tracers that are independent of and complementary to archaeological analyses.

. Younes G. et al (2024). Journal of Archaeological Science: Reports, 53, 104303.
. Sheisha H. et al (2023). Quaternary Science Reviews, 312, 108172.
. Sheisha H. et al (2022). PNAS, 119(37), e2202530119.