Definition of "craton" [craton]

• A large portion of a continental plate that has been relatively undisturbed since the Precambrian era and includes both shield and platform layers. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Kimberlite pipes are created when magma bubbles up through a craton, expanding and cooling on its way up."
• "But Fipke knew that, 100 miles under those pipes, was a craton, a thick, old chunk of continental plate where diamonds form."
• "If the craton has diamonds in it, the result is either a carrot-shaped, diamond-studded pipe reaching up to the surface or a wide, flat underground structure called a dike."