Researchers working in Greenland have found traces of microbial life in our planet's most ancient rocks. The discovery pushes back the oldest evidence of life on Earth by about 220 million years, showing just how habitable our planet was during its earliest stages.
A new study suggests that plate tectonics -- the dynamic processes that formed Earth's mountains, volcanoes and continents -- began about 3 billion years ago. By analyzing trace element ratios that correlate to magnesium content in ancient Earth's crust, the researchers provide first-order geochemical evidence for when plate tectonics first got underway.
