Broad areas of it that have undergone little tectonic modification are called cratons or shields, and often contain exposed Precambrian basement rock.
This particular region of the solid earth contains the Conrad discontinuity, above which lies felsic sial. Ophiolites are foreign bodies that may be emplaced here at fore-arcs. Collisional orogenies only occur here. Broad areas of it that have undergone little tectonic modification are called cratons or shields, and often contain exposed Precambrian basement rock. This part of the lithosphere, which was mostly formed about 3 billion years ago, is characterized by decreased maficity and hence decreased basalt content. Because it is relatively low-density, it cannot be subducted. For 10 points, name this part of the crust that is generally exposed to the atmosphere.
This particular region of the solid earth contains the Conrad discontinuity, above which lies felsic sial.
continental crust [prompt on "crust"]