New research led by the University of Aberdeen in Scotland has found that an unprecedented abundance of ocean life played a fundamental role in the creation of Earth’s mountains approximately two billion years ago.
While the formation of mountains is generally linked to the collision of tectonic plates causing large stabs of rock to be thrust skywards, this new study has identified another possible trigger. The abundance of nutrients in the oceans two billion years ago caused an unprecedented explosion in planktonic life.
When the plankton died, they fell to the bottom of the ocean, eventually forming graphite that played an important role in enabling rocks to stack on top of each other, ultimately forming mountains.
“Mountains are an essential part of the landscape, but big mountain chains only formed half-way through Earth’s history, about two billion years ago,” said study lead author John Parnell, a geoscientist at the University of Aberdeen.
“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.”
According to Parnell, clear evidence of these processes can be found in the northwest of Scotland, in places such as Harris, Gairlock, or Tiree, where the roots of ancient mountains, together with the graphite that helped build them, show the strong plausibility of this hypothesis.
“Graphite buried in Earth’s crust is in high demand for future green technology, for use in items such as fuel cells and lithium-ion batteries,” added study co-author Dr. Connor Brolly, a technician in the School of Geographical and Earth Sciences at the University of Glasgow.
“It’s interesting to think that this two-billion-year-old event which was responsible for shaping our natural world now has the potential to play a key role in its preservation for future generations.”
According to Professor Parnell, this study, recently published in the journal Nature Communications: Earth & Environment, has revealed that the key to the formation of mountains was life, proving that the Earth and its biosphere are linked in ways not previously understood.