noun, plural un·con·form·i·ties.
- lack of conformity; incongruity; inconsistency.
- Geology.
- a discontinuity in rock sequence indicating interruption of sedimentation, commonly accompanied by erosion of rocks below the break.
- the interface between such strata.
noun plural -ties
- lack of conformity
- the contact surface between younger and older rocks representing a discontinuity in the geological record. Most commonly it represents an erosional surface
n.c.1600, from un- (1) “not” + conformity. Geological sense is from 1829.
- 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.