unconformity

[ uhn-kuhn-fawr-mi-tee ]

noun

, plural un·con·form·i·ties.

1. lack of conformity; incongruity; inconsistency.
2. Geology.
   1. a discontinuity in rock sequence indicating interruption of sedimentation, commonly accompanied by erosion of rocks below the break.
   2. the interface between such strata.

unconformity

/ ˌʌnkənˈfɔːmɪtɪ /

noun

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

unconformity

/ ŭn′kən-fôr′mĭ-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.

Word History and Origins

Origin of unconformity¹

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

Example Sentences

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

From Project Gutenberg

As shown in Figure 207, a strong unconformity (nm´, Fig. 207) parts the schists and the Algonkian.

From Project Gutenberg

Such an erosion surface, called an “unconformity,” marks a gap in the geological record of the district where it occurs.

From Project Gutenberg

An unconformity may indicate that the beds below it have at some time been raised above the sea and have been eroded.

From Project Gutenberg

If beds of rock may be regarded as leaves in the volume of geologic history, an unconformity marks a gap in the record.

From Project Gutenberg

Related Words

• abnormality
• alteration
• change
• deviation
• discrepancy
• disparity
• divergence
• diversity
• fluctuation
• innovation
• modification
• mutation
• shift
• variety