Final answer:
In geology, a disconformity is the type of unconformity that exists between parallel rock layers, represented as a gap in the sedimentary record due to erosion followed by deposition of new layers.
Step-by-step explanation:
An unconformity between parallel rock layers is known as a disconformity. A disconformity is an erosional surface separating younger from older sedimentary rock layers that are parallel to each other. This type of unconformity is the result of deposition, erosion, and renewed deposition, where the sea level changes and exposes rocks to erosion before new sediments are laid down again.
In contrast, an angular unconformity involves tilted sedimentary layers that are overlain by younger, flat-lying layers. A nonconformity occurs between horizontal sedimentary rock layers and the underlying igneous or metamorphic bedrock. Lastly, a paraconformity indicates a gap in deposition but lacks clear evidence of erosion.