How to interpret the use of late and early Tertiary from older literature?

Question

When reading older papers how should I interpret the use of "Late Tertiary" and "Early Tertiary"? Would these periods equate to Paleogene and Neogene, or was there a different accepted boundary age between the Late and Early Tertiary?

Answer 1

A reasonable assumption would, in fact, be that Early Tertiary and Late Tertiary correspond to Paleogene and Neogene, respectively.