deep time

noun

Time that is considered on the vast scale of geology or the universe, rather than on the scale of human history.

Meanings

noundeep time (uncountable)
  1. uncountableTime that is considered on the vast scale of geology or the universe, rather than on the scale of human history.

    The organization of deep time was the special mission of geology, and it set about chronicling rocks into a temporal stratigraphy.

    2012, Lydia Pyne, Stephen J. Pyne, “Eiszeit and Zeitgeist”, in The Last Lost World, Penguin, →ISBN
    5 more examples

    Numbers do not seem to work well with regard to deep time. Any number above a couple of thousand years—fifty thousand, fifty million—will with nearly equal effect awe the imagination to the point of paralysis.

    1981, John McPhee, Basin and Range, New York: Farrar, Straus, Giroux, →ISBN, page 20

    Yet deep time seemed impervious to the methods of conventional history writing, a state of affairs captured in the word coined to describe this newly remote past: prehistory.

    2011, Andrew Shryock, Daniel Lord Smail, Deep History: The Architecture of Past and Present, University of California Press, →ISBN, page x

    But Hutton’s insights really came into their own in the Romantic era of the 19th century. The affective register of deep time was one of terror and wonder, fashioned to fit a vision of the sublime that transcended and yet somehow affirmed humanity.

    2016 October 31, David Farrier, “How the Concept of Deep Time Is Changing”, in The Atlantic

    The events of 1859 brought humans and geology together. The idea of deep time was not new. It had been conclusively demonstrated by the international efforts of many geologists culminating, for the British, in Charles Lyell's (1797–1875) Principles of Geology published in three volumes between 1830 and 1833—a book which accompanied Darwin on The Beagle.

    2021, Clive Gamble, Making Deep History: Zeal, Perseverance, and the Time Revolution of 1859, Oxford University Press, →ISBN

    Sellafield compels this kind of gaze into the abyss of deep time because it is a place where multiple time spans – some fleeting, some cosmic – drift in and out of view.

    2022 December 15, Samanth Subramanian, “Dismantling Sellafield: the epic task of shutting down a nuclear site”, in The Guardian
  2. uncountableTime that is set in the very distant past or far into the future.

Origin

Coined by American writer John McPhee in 1981.

Full word history & related roots →
Cite this entry
APA

deep time. (n.d.). In WatkinsX Dictionary. Retrieved November 2, 2026, from https://dictionary.watkinsx.com/word/deep%20time

MLA

“deep time.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/deep%20time. Accessed November 2, 2026.

Chicago

WatkinsX Dictionary, s.v. “deep time,” accessed November 2, 2026, https://dictionary.watkinsx.com/word/deep%20time.

Source: deep time on Wiktionary, CC BY-SA 4.0.