For more than a century every textbook has given the same answer. The Great Sphinx of Giza was carved around 2500 BC, in the reign of the pharaoh Khafre. Then a geologist went and looked at the rock.
In 1990 Robert Schoch, a professor at Boston University with a doctorate in geology from Yale, traveled to Egypt at the invitation of the independent researcher John Anthony West. Schoch expected to settle the matter quickly. Instead he found himself staring at the walls of the pit the Sphinx sits in.
They are cut with deep vertical fissures and rounded, rolling profiles. To a geologist, he said, that is the classic signature of rainwater, of water pouring down the rock face for thousands of years. Wind and sand leave a different mark, sharp horizontal scouring, and you can see it on other Giza monuments of the accepted age.
The problem is that Egypt has been desert for the last five thousand years. The last time heavy rains fell on Giza was far earlier. Schoch put the carving of the core body somewhere between 5000 and 7000 BC, and perhaps much older.
When he presented his findings to the Geological Society of America in 1992, many fellow geologists agreed with his reading of the rock. Egyptologists did not. One asked where the civilization was that could have done it. There was no evidence, they said, of anyone that advanced, that early.
That was before Göbekli Tepe was dug out of a hill in Turkey and dated to 9600 BC.
What if the Sphinx was already ancient when the first pharaoh laid eyes on it.
Unusual weathering, or a monument from a lost chapter of history?






