Tag «phanerozoic»

When a Billion Years Disappeared

When a Billion Years Disappeared

When geologist Clarence Dutton first saw the Grand Canyon in 1880, he was spellbound by its colorful walls. The Grand Canyon’s walls are made up of rock layers, each representing a distinct period of Earth’s history. And some of the lower rock beds–deep down in the canyon–look kind of tilted. Dutton knew these layers were …

History of the Earth

History of the Earth

(4410) Latest appearance of water – By this time, water could be found Earth’s surface, though it would have been highly acidic. (4000) Formation of the magnetic field – The magnetic field was active by this time, though about 10-50% of its strength today. (2500) Great Oxygenation Event – Oxygen begins to accumulate in the …

A Brief History of Geologic Time

A Brief History of Geologic Time

The tale of life on Earth has been unfolding for about 4 billion years. And we humans are just the last word on the last page of that story. At least so far. And the vast stretches of time that are covered by the history of life can be hard for us to fathom. We …