Earth's crust may be building mountains by dripping into the mantle

Earth's crust may "drip" into its middle layer under growing mountain ranges.

This odd process, called lithospheric dripping, has been proposed to occur under the Andes, in Central Asia, in the U.S. Pacific Northwest and along the west coast of Canada. Now, researchers have found that the Anatolian plateau in Turkey is undergoing a similar process.

The findings could reveal how mountains and basins are built on planets like Venus or Mars, where there are no mobile tectonic plates like the ones that crumple into one another to create topography on Earth.

"It's [about] understanding how tectonics might work on planets that don't have plates," said study author A. Julia Andersen, a doctoral student in tectonophysics at the University of Toronto. "Earth is the only planet we know of that has plates in the solar system, but the other planets aren't flat."

Volcanic eruptions can spill lava on these planetary surfaces. But landforms can also be created when the lithosphere, which consists of the crust and the relatively brittle upper layer of the mantle, gets especially thick. Mountains create a lot of pressure on the lower lithosphere. In the high-pressure zones underneath the towering peaks, new mineralization can occur, Andersen told Live Science. Some of these minerals are denser than the mantle below.

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"In any sort of physical system, if you have a higher-density material on top of a lower-density material, then it sinks or drips," she said.