Assertion: aquifer | /r/HasProperty | overlain by thick shale
Facets:
value: pennsylvanian
type: LOCATION
Source sentences:
text: Along the outcrop belt of these rocks, the Mississippian aquifer is overlain by alluvium, loess, and glacial drift, while elsewhere the aquifer is first overlain by thick shale and lesser sandstone units (Pennsylvanian).