Columbia subject headings:
Geology, Stratigraphic--Cretaceous.
Geology--Texas--Austin Region--Guidebooks.
Volcanoes--Texas.
Harvard subject headings:
Geology, Stratigraphic--Cretaceous
Geology--Texas--Austin Region--Guidebooks.
Geology--Texas--Guidebooks.
Volcanism--Texas--Austin Region--Guidebooks.
Volcanoes--Texas.
Princeton subject headings: