Geologist John Wesley Powell gazes towards the rocky slopes that rise on both sides from the river below. He can see that something is wrong with the towering rocks. It is 1869, and Powell is on an expedition into the unexplored regions of south-western USA. Together with nine other men, he is tackling the dangerous Colorado River in an effort to research and map the American wilderness. During the three-month mission, four of the men will leave the expedition, fearing for their lives. But Powell continues on. He is on the track of something big. The river has led him into the huge Grand Canyon, where he can see the individual layers of rock clearly revealed. The layers of sand, clay and lime have settled on top of each other since Earth’s early childhood, storing evidence of our planet’s life over hundreds of millions of years. But this rock archive of Earth’s history is incomplete. Powell has just noticed that a big chunk of it is missing.
Today, 150+ years later, scientists know that Powell’s discovery can be duplicated on all continents, and that the missing evidence covers more than a billion years – a period from 1.8 to 0.6 billion years ago.
But how was Earth robbed
