The era that あなた are referring to is called "The Hadean Era", this was the earliest known era of Earth when it was still being continually bombarded によって asteroids, and comets. Where instead of flowing water, there was flowing oceans of searing hot lava and magma and also the earliest volcanoes and scorched land masses.. And "Hadean" is referring the the Greek god of the アンダーワールド called "Hades" also a reference and likeness to hell itself.
