Then come Lyell’s epochs—the Pleistocene, Miocene, and so on—which apply only to the most recent (but palaeontologically busy) 65 million years; and finally we have a mass of finer subdivisions known as stages or ages. Most of these are named, nearly always awkwardly, after places: Illinoian, Desmoinesian, Croixian, Kimmeridgian and so on in like vein. Altogether, according to John McPhee, these number in the “tens of dozens.” Fortunately, unless you take up geology as a career, you are unlikely ever to hear any of them again.
