The study, published in the Nature journal, Communications Earth and Environment, suggests that “increased biomass and carbon burial around 2 billion years ago triggered mountain building”.
By collecting data from previously published studies on mountain formation and buried marine biomass, the landmark study undertook a detailed case study of 20 mountain ranges around the world. It concluded that the sheer abundance of plankton contributed to the movement of tectonic plates, therefore helping the creation of mountain ranges.
While past studies have already indicated that tectonic plates were weakened by graphite which resulted in the creation of mountains, how exactly this happened was less clear.
According to the new study, the oceans saw a big surge of plankton around 2 billion years ago which many suspect to be tied in with the so-called ‘Great Oxidation Event’. The abundance of plankton was feeding off the ocean’s nutrients and when it died, it would settle at the bottom of the ocean where it would form a layer of graphite – a stable carbon layer that is known to lubricate the breakage of rocks into slabs. These slabs would then be more likely to stack on top of each other which would eventually form mountains.
Prof John Parnell who led the landmark study said: “We can see the evidence in the northwest of Scotland, where the roots of the ancient mountains and the slippery graphite that helped build them can still be found, in places like Harris, Tiree, and Gairloch.”
“Our research shows that it was the sheer abundance of carbon in the ocean that played a crucial role in the crustal thickening that built the Earth’s mountain ranges. The geological record for this period includes evidence of an abundance of organic matter in the oceans, which when they died were preserved as graphite in shale. While it has long been known that tectonic processes were lubricated, our research shows that it was the sheer abundance of carbon in the ocean that played a crucial role in the crustal thickening that built the Earth’s mountain ranges,” he added.
“Ultimately what our research has shown is that the key to the formation of mountains was life, demonstrating that the Earth and its biosphere are intimately linked in ways not previously understood,” Parnell concluded.
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Photography courtesy of Unsplash.