Columbia subject headings:
Geology, Stratigraphic.
Geology--Alps.
Geology--North America.
Geology--Scotland.
Harvard subject headings:
Geology, Stratigraphic.
Geology--Alps
Geology--North America
Geology--Scotland
Princeton subject headings:
Geology, Stratigraphic.
Geology--Alps.
Geology--North America.
Geology--Scotland.