from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun A large portion of a continental plate that has been relatively undisturbed since the Precambrian Era and includes both shield and platform layers.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun A part of the
Earth’s crustthat has survived the splitting and merging of continents.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun the part of a continent that is stable and forms the central mass of the continent; typically Precambrian
from The American Heritage® Dictionary of the English Language, 4th Edition
from Wiktionary, Creative Commons Attribution/Share-Alike License
Kimberlite pipes are created when magma bubbles up through a craton, expanding and cooling on its way up.
The greenstones of the Kaapvaal craton in the northeast have been found to contain unicellular and biogenic filamentous structures, signs of some of the earliest forms of life.
Fipke also knew that the craton underneath the pipes he had found ran all the way up the Rockies.
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.
The craton of North America has been relatively stable for about 600 million years.
Together the shield and platform form what geologists call a craton.
The continents of Australia, North America, South America, and Africa each have a single continuous craton forming their nucleus.
The platform and the basement rock together form a craton.
With two thirds of the country covered with the craton-type soil, in which the kimberlite stone which bears diamonds can be found, there has been a steady increase in diamond prospecting.