Horizon Reborn

The Message of the Sphinx was a book written by Graham Hancock and Robert Bauval which argued that the creation of the Sphinx and Pyramids can be pushed back as far as 10,500 BC using astronomical data.
Working from the premise that the Giza complex encodes a message, they begin with recently discovered geological evidence indicating that the deep erosion patterns on the flanks of the Sphinx were caused by 1000 years of heavy rain. Such conditions last existed in Egypt at the end of the last ice age, about 10,000-9,000 B.C., meaning that the Sphinx may be more than 12,000 years old (not the generally accepted 4500 years). The authors go on to suggest, using computer simulations of the sky, that the pyramids, representing the three stars of Orion's Belt, along with associated causeways and alignments, constitute a record in stone of the celestial array at the vernal equinox in 10,500 B.C. This moment, they contend, represents Zep Tepi, the "First Time," often referred to in the hieroglyphic record. They claim that the initiation rituals of the Egyptian pharaohs replicate on Earth the sun's journey through the stars in this remote era, and they suggest that the "Hall of Records" of a lost civilization may be located by treating the Giza Plateau as a template of these same ancient skies.

*
The theory of an older Sphinx has received some support from geologists. Most famously, Robert M. Schoch has argued that the effects of water erosion on the Sphinx and its surrounding enclosure means that parts of the monument must originally have been carved at the latest between 7,000–5,000BC. Schoch's analysis has been broadly corroborated by another geologist, David Coxill, who agrees that the Sphinx has been heavily weathered by rainwater and must therefore have been carved in pre-dynastic times. While a third geologist, Colin Reader, has suggested a date several hundred years prior to the commonly accepted date for construction. These views, however, have been almost universally rejected by mainstream Egyptologists who, together with a number of geologists, eg James Harrell, Lal Gauri, John J. Sinai, and Jayanta K. Bandyopadhyaym, stand by the conventional dating for the monument. Their analyses attribute the apparently accelerated wear on the Sphinx variously to modern industrial pollution, qualitative differences between the layers of limestone in the monument itself, scouring by wind-borne sand, and/or temperature changes causing the stone to crack.