discontinuity

noun, plural dis·con·ti·nu·i·ties.

1. lack of continuity; irregularity: The plot of the book was marred by discontinuity.
2. a break or gap: The surface of the moon is characterized by major discontinuities.
3. Mathematics. a point at which a function is not continuous.
4. Geology. a zone deep within the earth where the velocity of earthquake waves changes radically.

noun plural -ties

1. lack of rational connection or cohesion
2. a break or interruption
3. maths
   1. the property of being discontinuous
   2. the point or the value of the variable at which a curve or function becomes discontinuous
4. geology
   1. a zone within the earth where a sudden change in physical properties, such as the velocity of earthquake waves, occurs. Such a zone marks the boundary between the different layers of the earth, as between the core and mantleSee also Mohorovičić discontinuity
   2. a surface separating rocks that are not continuous with each other

1. A usually uneven surface between two layers of rock or sediment that represents either an interruption in the deposition of the layers, as in an unconformity, or a displacement of one or both layers relative to each other, as in a fault.
2. A surface within the Earth across which the velocities of seismic waves change. The discontinuities are located at the boundaries between the Earth’s various layers and correspond to changes in the elastic properties of the Earth’s materials.