Vitrified Forts
Vitrified forts or, forts where the rock was heated, so much so, that it turned into glass or, had “vitrified”. There seem to be quite a few of these forts.
Robert M. Schoch has an interesting angle on the subject.
Plasma hitting the surface of Earth could heat and fuse rock, incinerate flammable materials, melt ice caps, vaporize shallow bodies of water creating an extended deluge of rain, and send the climate into a warming spell. The release of pressure that follows the melting of thousands-of-meters-thick ice sheets can induce earthquakes and even cause hot rock under pressure to melt and erupt to the surface as volcanoes. The world was in chaos, and this is the event recorded by petroglyphs and the rongorongo texts.
The plasma event of 9700 B.C. eradicated advanced civilizations and high cultures of the time, and the radiation emanating from the plasma may have affected mental and psychical abilities. This could be the basis for the nearly universal myth of a Golden Age, a time when beings on Earth had mental abilities far surpassing those of later times. The 9700 B.C. event may be the original basis for the Atlantis legends; the timeframe fits well with Plato’s account.