Columbia subject headings:
Earth (Planet)--Crust.
Earth (Planet)--Mantle.
Geology--United States.
Geophysics--United States.
Harvard subject headings:
Earth (Planet)--Crust.
Earth (Planet)--Mantle.
Geology--United States
Geophysics--United States.
Princeton subject headings:
Earth (Planet)--Crust.
Earth (Planet)--Mantle.
Geology--United States.
Geophysics--United States.