geological ory o four spans of time: primary, secondary,tertiary, and quaternary. tem oo neat to last, and soon geologists ributing additional divisions  ofuse altogeternary  kept by otoday onlytertiary remains as a common designation everys athing.

    Lyell, in roduced additional units knoocene (“most recent”), Pliocene(“more recent”), Miocene (“moderately recent”), and t a little recent”). Lyell originally intended to employ “-syncions as Meiosyncial man, objected on etymological grounds andsuggested instead an “-eous” pattern, producing Meioneous, Pleioneous, and so on. terminations hing of a compromise.

    Noime is divided first into four greatc life”). to anyy subgroups, usually called periods timesknoems. Most of taceous, Jurassic,triassic, Silurian, and so on.

    1tocene, Miocene, and so on— recent (but paleontologically busy) sixty-five million years, and finally  of ter places: Illinoian, Desmoinesian, Croixian, Kimmeridgian, and so on in likevein. Altogeto Joens of dozens.”

    Fortunately, unless you take up geology as a career, you are unlikely ever to hemagain.

    Furtter is t tages or ages in Nortnames from tages in Europe and often only rougersect in time. tian stage mostly corresponds age in Europe, plus atiny bit of tly earlier Caradocian stage.

    Also, all textbook to textbook and from person to person, so t someauties describe seven recent epocent oo, you ertiary and quaternary taken out and replaced by periods of differentlengto t