Mountains could have growth spurts: researchers

Beneath the crust, the buckling creates a heavy "root" that anchors the crust, Garzione said.

Conventional theory says that movement of the fluid mantle deep in the Earth slowly erodes this heavy root, allowing mountains to rise gradually as the crust shortens and thickens.

But Garzione proposes an alternative theory -- that delamination causes the root to heat up and ooze downward like a drop of thick syrup, abruptly breaking free and sinking into the hot mantle. The mountains above, suddenly free of the root, then spring up.

Her team is now looking to see evidence of what effects the sudden appearance of such a tall mountain range would have had on climate and evolution.

(Reporting by Maggie Fox; Editing by Will Dunham and Xavier Briand)