Nile waterscapes facilitated the construction of the Giza pyramids during the 3rd millennium BCE

Abstract

The pyramids of Giza originally overlooked a now defunct arm of the Nile. This fluvial channel, the Khufu branch, enabled navigation to the Pyramid Harbor complex but its precise environmental history is unclear. To fill this knowledge gap, we use pollen-derived vegetation patterns to reconstruct 8,000 y of fluvial variations on the Giza floodplain. After a high-stand level concomitant with the African Humid Period, our results show that Giza’s waterscapes responded to a gradual insolation-driven aridification of East Africa, with the lowest Nile levels recorded at the end of the Dynastic Period. The Khufu branch remained at a high-water level (∼40% of its Holocene maximum) during the reigns of Khufu, Khafre, and Menkaure, facilitating the transportation of construction materials to the Giza Pyramid Complex.

Pyramid building and collapse

“…At the construction of the High Aswan Dam 50 y ago, Nile flow seasonal inundation ceased forever, but, as Sheisha et al. ( 3 ) document, its dynamic Holocene history remains preserved within its riparian sediments.…”

“…Lithology evidence for the Nile flow 4.2 ka BP event is presented by Sheisha et al.’s ( 3 ) SI Appendix, figure S1, where cores Giza 1 and 4 document the abrupt intrusion of sand strata into otherwise unbroken Nile channel flow silts. The interpolated radiocarbon dates for the interruption begin ∼4250 y BP and end ∼3900 y BP (±85 y), similar to the higher-resolution Nile flow and ISM megadrought records.…”

“…In PNAS, Sheisha et al. ( 3 ) provide the Giza channel flow data within an 8,000-y record derived from sediment cores analyzed for pollen and lithic stratigraphy and radiocarbon dates.…”

“…Sheisha et al. ( 3 ) estimate, from their proxy pollen data, a 10% reduction at ∼4.2 ka BP in local Khufu channel flow. Another estimate is provided by the transfer of measured ISM speleothem alterations to ISM precipitation reductions for Nile flow.…”

Enhanced continental weathering (δ7Li,εNd) during the rise of East African complex polities: an early large-scale anthropogenic forcing?

“…years BP has been associated with changes in the annual cycle of the Nile summer floods [e.g. Manning et al, 2017, Sheisha et al, 2022 suggesting a relationship between the end of the African Humid Period (AHP) and the Protodynastic period in Egypt.…”