Columbia subject headings:
Geology, Stratigraphic--Precambrian.
Geology--Great Britain.
Geology--North Atlantic Region.
Harvard subject headings:
Geology, Stratigraphic--Precambrian
Geology--Great Britain
Geology--North Atlantic Ocean Region.
Princeton subject headings:
Geology, Stratigraphic--Precambrian.
Geology--Great Britain.
Geology--North Atlantic Ocean Region.