Question

which statement explains one reason why unconformities occur? rocks along a fault break and move. igneous rock forms at earths surface. no sediment is deposited over a long time. igneous rock forms between sedimentary layers.

Explanation:

Unconformities occur when there is a gap in the geological record. Igneous rock forming between sedimentary layers can create an unconformity as it disrupts the normal sequence of sedimentary deposition. Sediment deposition over time doesn't directly explain unconformities. Igneous rock forming at Earth's surface doesn't relate to unconformities in the way described. Rock movement along a fault is about fault - related processes, not the main reason for unconformities.

Answer:

Igneous rock forms between sedimentary layers.