[ uhn-kuhn-fawr-mi-tee ]
See synonyms for unconformity on Thesaurus.com
noun,plural un·con·form·i·ties.
  1. lack of conformity; incongruity; inconsistency.

  2. Geology.

    • a discontinuity in rock sequence indicating interruption of sedimentation, commonly accompanied by erosion of rocks below the break.

    • the interface between such strata.

Origin of unconformity

First recorded in 1590–1600; un-1 + conformity

Words Nearby unconformity

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use unconformity in a sentence

  • An unconformity thus records movements of the crust and a consequent break in the deposition of the strata.

    The Elements of Geology | William Harmon Norton
  • As shown in Figure 207, a strong unconformity (nm´, Fig. 207) parts the schists and the Algonkian.

    The Elements of Geology | William Harmon Norton
  • Such an erosion surface, called an “unconformity,” marks a gap in the geological record of the district where it occurs.

    Geology | William J. Miller
  • An unconformity may indicate that the beds below it have at some time been raised above the sea and have been eroded.

    Geology | William J. Miller
  • If beds of rock may be regarded as leaves in the volume of geologic history, an unconformity marks a gap in the record.

    Geology | William J. Miller

British Dictionary definitions for unconformity


/ (ˌʌnkənˈfɔːmɪtɪ) /

nounplural -ties
  1. lack of conformity

  2. the contact surface between younger and older rocks representing a discontinuity in the geological record. Most commonly it represents an erosional surface

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for unconformity


[ ŭn′kən-fôrmĭ-tē ]

  1. A surface between successive strata representing a missing interval in the geologic record of time, produced either by an interruption in deposition or by the erosion of depositionally continuous strata followed by renewed deposition. An unconformity is a type of discontinuity.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.