These sources of error in part neutralise one another. Some make
our resulting age too long, others make it out too short. But we
do not know if a balance of error does not still remain. Here,
however, is a table of deposits which summarises a great deal of
our knowledge of the thickness of the stratigraphical
accumulations. It is due to Sollas.[1]

Feet.

Recent and Pleistocene - - 4,000
Pliocene - - 13,000
Miocene - - 14,000
Oligocene - - 2,000
Eocene - - 20,000
63,000

Upper Cretaceous - - 24,000
Lower Cretaceous - - 20,000
Jurassic - - 8,000
Trias - - 7,000
69,000

Permian - - 2,000
Carboniferous - - 29,000
Devonian - - 22,000
63,000

Silurian - - 15,000
Ordovician - - 17,000
Cambrian - - 6,000