Stromatolites: layered rocks built by first life
Dated 3700 million years in Greenland, stromatolites are bacterial mats that made our oxygen.
3.7-billion-year rocks that breathe
Greenland stromatolites date 3.7 billion years, built when cyanobacteria mats trapped mud layer by layer, growing only 0.5 millimeters ежегодно into domes. in total today for sure
For 2 billion years they ruled Earth, with 3.4-billion-year Western Australia reefs stretching 10 kilometers and pumping oxygen from zero to 21 percent. in total today for sure
Living ones in Shark Bay today
Shark Bay in Australia hosts 1000 living domes in water twice as salty as oceans, where 3000-year-old mounds rise 1 meter and 50-degree heat. in total today for sure
They look like gray rocks but teem with trillions of cells, and scientists study 2-millimeter layers to track ancient climates and search Mars for समान domes.
- Oldest are 3.7 billion years in Greenland
- Grow 0.5 millimeters ежегодно
- Made oxygen rise to 21 percent
- Shark Bay has 1000 living domes
- Mounds live 3000 years