The new study’s results show that sea salt content an unique information that reveals when oxygen entered Earth’s atmosphere. The research team from the Geological Survey of Norway and Princeton University has studied the two-billion-old 800-metre thick layer of marine salt deposits from Onega basin located in Russian Karelia.
The scientists revealed that at that geological time, oxygen levels in the sea and the atmosphere was higher than previously thought. According to geologist Aivo Lepland,
“The presence of the sulfates and other minerals in the sample make it possible to estimate the proportion and changes in the oxygen in the Earth’s atmosphere at the time the salt was deposited.”
The research team led by the geochemist Clara Blättler from Princeton University has found out that ancient marine salt deposits contains the salt crystals from so far back in geological time. For the science, it is priceless.
Sulfates played a significant role
At this time, scientists are uncertain how oxygen entered the Earth’s atmospheric system in the first place. Some believe it has happened gradually, over several hundreds of millions of years, while others believe that it could have changed abruptly.
Geochemist Clara Blättler believes that the new results support a sudden jump in oxygen levels rather than gradual increase. The press release reads:
“The large accumulation of sulfate that we see from our observations favors a much more dramatic transition. You have to push the system really hard to accumulate this much sulfate.”
This research is considered an important step forward in understanding why the Earth’s great oxygenation occurred, but also in a larger context, why we are all here.