Viewed from orbit, the largest mine ever discovered in America is 4000 trillion litres beneath this. the Marcellus Shale, ...

the researchers concluded that the decorated stones were deliberately placed there around 2900 B.C. The vast majority of the stone plaques were made from black shale — a dark, flaky sedimentary ...

Archaeologists uncover 614 stone plaques in Denmark’s Bornholm Island, linking Neolithic sacrifices to a volcanic eruption in 2910 B.C.