Schoch was the first geologist to date the age of the great Sphinx to at least 9700 years old. Along with John Anthony West they formed the first discoveries of archo-geology.
In 1990 they first traveled to Egypt with the sole purpose of examining the Great Sphinx from a geological perspective. Schoch assumed that the Egyptologists were correct in their dating, but soon he discovered that the geological evidence was not compatible with what the Egyptologists were saying. On the body of the Sphinx, and on the walls of the Sphinx Enclosure (the pit or hollow remaining after the Sphinx’s body was carved from the bedrock), Schoch found heavy erosional features that I concluded could only have been caused by rainfall and water runoff. The thing is, the Sphinx sits on the edge of the Sahara Desert and the region has been quite arid for the last 5000 years. Furthermore, various structures securely dated to the Old Kingdom show only erosion that was caused by wind and sand (very distinct from the water erosion). To make a long story short, Robert Schoch came to the conclusion that the oldest portions of the Great Sphinx, what he refer to as the core-body, must date back to an earlier period (at least 5000 BCE, and my latest research now points to the end of the last ice age, circa 10,000 BCE), a time when the climate was very different and included more rain.