After examining a sequence of horizontal sedimentary rocks, a geologist determines that there is a considerable span of time for which no sedimentary rock layers exist at this location. The geologist discovered _____.

Question

a sequence of correlated strata

a nonconformity

a disconformity

an angular unconformity

Answer 1

The geologist discovered a disconformity.

A disconformity is a type of unconformity that occurs when there is a gap in the geological record between two layers of sedimentary rock that are parallel to each other. This indicates a period of erosion or non-deposition, which aligns with the geologist's observation of a considerable span of time with no sedimentary rock layers present at the location.