What Was Happening on Earth at This Time The Precambrian is the earliest of the geologic ages, which are marked by different layers of sedimentary rock. Laid down over millions of years ...

Ancient Rock-Shelter Discovered; Reveal Migration Evidence of 3 Metapopulations on Site Spanning 130,000 Years The Soi Havzak ...

The next layer is the mantle. Many people think of this as lava, but it's actually rock. The rock is so hot, however, that it flows under pressure, like road tar. This creates very slow-moving ...

undisturbed volcanic rock 3,850 million years old lies atop sedimentary rock. Within this deeper (and older) layer are minerals that contain telltale signs of past biological activity: carbon ...