Both arches intersect Archean Cratons, the Buffalo Head and the Hearne Province cratons. |
Kober could not know that today, 90 years later, cratons would be objects of intense study. |
This accounts for the great age of the rocks comprising the continental cratons. |
Mobile belts of various ages seem to have stitched Africa's Archean cratons together by Himalayan-style continental collisions. |
Diamond is obtained from volcanic pipes composed of kimberlite or lamproite, rocks that are found only in cratons, very old stable areas of the Earth's crust. |
Although continents were small, they consisted of stable cratons. |