Columbia subject headings:
Appalachian Basin--Charts, diagrams, etc.
Appalachian Basin--Maps.
Geological cross sections--Appalachian Basin.
Geological cross-sections.
Geological maps.
Geology, Stratigraphic--Silurian--Charts, diagrams, etc.
Maps.
Petroleum--Geology--Appalachian Basin--Charts, diagrams, etc.
Sedimentation and deposition--Appalachian Basin--Charts, diagrams, etc.
Harvard subject headings:
Geology, Stratigraphic--Silurian--Charts, diagrams, etc.
Petroleum--Geology--Appalachian Basin--Charts, diagrams, etc.
Princeton subject headings: