Claim that the vertical, undulating weathering of the Great Sphinx enclosure at Giza was cut by prolonged rainfall rather than by wind and sand, which would place the carving in a wetter climate long before dynastic Egypt. Advanced by the writer John Anthony West and developed by the geologist Robert Schoch, who presented it to the Geological Society of America in 1991 and put the original carving at 7000 to 5000 BC. Egyptologists reject it on the grounds that no culture capable of the work is attested in Egypt then and that the quarrying record contradicts it. The geological rebuttals name other mechanisms: K. Lal Gauri and colleagues in 1995 attributed the profile to differential weathering of alternating hard and soft limestone strata, and the enclosure channels to pre-Pliocene karst features exposed by quarrying, while James Harrell in 1994 proposed salt weathering driven by wet wind-blown sand. A 2015 study by Ioannis Liritzis and Asimina Vafiadou returned six surface luminescence dates for the temple stonework spread from about 3100 down to 1050 BCE, not a cluster; because the method records a surface’s last exposure rather than its first, Robert Schoch reads them as dating reworking rather than building.
Where the dating now sits
Schoch’s own estimate has moved twice. The 1992 KMT paper gave 7000 to 5000 BCE; the 2016 brackets inside its reprint in Origins of the Sphinx say he “severely underestimated the age of the original structure”, and the recalibration reaches circa 10,000 BCE. The instrumented basis for both is the 1991 Sphinx Seismic Survey, whose depth ratio only becomes a date once a 2500 BCE baseline and a roughly linear weathering rate are assumed.
The middle position
Colin Reader accepts the rainfall reading and dates the excavation to the early dynastic period, a few centuries before Khafre rather than seven thousand years. A separate 2023 experiment by Boury, Weady and Ristroph in Physical Review Fluids showed that sphinx-like forms arise on their own as wind-carved yardangs, which speaks to the shape the first carvers may have started from and says nothing about when.
Connections
Robert Schoch · Orion Correlation Theory · Graham Hancock · Great Sphinx · 1991 Sphinx Seismic Survey · Colin Reader · Origins of the Sphinx · Surface Luminescence Dating · Mark Lehner