萬物簡史 第84期:敲石頭的人們(16)

Lyell, in his Principles, introduced additional unitsknown as epochs or series to cover the period sincethe age of the dinosaurs, among them Pleistocene("most recent"), Pliocene ("more recent"), Miocene("moderately recent"), and the rather endearinglyvague Oligocene ("but a little recent").

萊爾在《原理》中使用了新的單位，叫做"世"或"段"來涵蓋恐龍以后的時代，其中有更新世("最近")、上新世("較近")、中新世("頗近")和意思很含糊的漸新世("有點兒近")。

Nowadays, and speaking very generally, geological time is divided first into four great chunksknown as eras: Precambrian, Paleozoic (from the Greek meaning "old life"), Mesozoic ("middlelife"), and Cenozoic ("recent life"). These four eras are further divided into anywhere from adozen to twenty subgroups, usually called periods though sometimes known as systems. Most ofthese are also reasonably well known: Cretaceous, Jurassic, Triassic, Silurian, and so on.

如今，一般來說，地質時代劃分為四大塊，叫做"代"：前寒武紀、古生代(源自希臘文，意為"古代生命")、中生代("中期生命")和新生代("新的生命")。這4個代又分為12-20個部分，通常叫做"紀"，有時候也稱"系"。其中大多數是大家比較熟悉的：白堊紀、侏羅紀、三疊紀、志留紀等等。