Without an explosion in ocean life more than 2 billion years ago, many of Earth's mountains might never have formed, according to new research.
When tiny organisms in the shallows of the sea, like plankton, die and sink to the bottom, they can add organic carbon to Earth's crust, making it weaker and more pliable.
A case study of 20 mountain ranges around the world, including those in the Rockies, the Andes, Svalbard, central Europe, Indonesia, and Japan, has now linked the timing of high carbon burial in the ocean with the very generation of our planet's peaks.
"The additional carbon allowed easier deformation of the crust, in a manner that built mountain belts, and thereby plate margins characteristic of modern plate tectonics," the researchers write.
The changes seem to have begun roughly 2 billion years ago, in the middle of the Paleoproterozoic Era, when biological carbon from plankton and bacteria began to add exceptionally high concentrations of graphite to the ocean floor's shale. This made the rock brittle and more likely to stack.
Within 100 million years, most mountain ranges began to form in these weakened slices of crust. Mountain ranges that emerged more recently follow the same pattern.
In the Himalayas, for instance, tectonic thrusting around 50 million years ago was focused on Paleoproterozoic sediments with the most organic-rich beds.
The timing and location implies that biological carbon in graphite continues to shape the geology of our planet. READ MORE...
