Ask GeoMan...
I am studying Geophysycal Engineering at UNAM, in Mexico. I have been doing some research on the web for a certain topic that is very difficult to find: What is a continental basement?
I think you are probably talking about the igneous and metamorphic rocks which make up the cores of the continents. These massive portions of the earth's crust are called a "craton" and "greenstone belt." Start with the question about these on the Ask GeoMan index page as a beginning, and then try typing either of those terms into your browser - I bet you'll be burried in information. If you still have trouble, or need additional help, get back to me.