Assertion: region | /r/HasProperty | underlain
Facets:
Source sentences:
text: The region is underlain by a thin layer of rich, black topsoil developed atop the chalk of the Selma Group, a geologic unit dating to the Cretaceous.
text: Although the surface of the High Plains consists of a veneer of deposits geologically recent, the region is underlain by a thick agglomeration of Permian deposits, below which are still older beds of the Early Paleozoic, which in turn rest on the pre-Cambrian basement.