"Buried in soil?" Chen Fan looked at the 10-meter flat area through the eyes of the electric eel. Without a doubt, this place must had been dry land, otherwise the lithographic stone couldn't possibly be buried 400 meters under the soil.
The earliest stone paintings date back to around 10,000 years ago. However, the origins of mankind can be traced back to 2 million years ago, so there was no way Chen Fan could verify the exact age of this stone. It was possible to salvage the stone and send it to the museum for carbon-14 dating, but not only would the stone be gone, it would also cause a lot of trouble, and Chen Fan did not intend to make the stone known to the public.
Judging from the lines on the stone, the big hole in the middle of the reefs should be around 100 meters in diameter. As for the depth, if the person who sculpted the map had some technical skills, the hole should be over 800 meters deep based on the comparison between the depicted width and length.
