Final answer:
The center of a basin may have older or younger strata relative to the edge depending on whether the structure is a syncline or anticline. Geologists use the principle of superposition, modified for the presence of folds, to determine the relative ages of these strata.
Step-by-step explanation:
The statement that the center of a basin has older/younger strata relative to its outer edge can be true depending on the geologic context. If the basin is arranged in a syncline—where rock layers fold downward—the center is likely to have younger strata, whereas in an anticline—where rock layers fold upward—the center will likely have older strata. The principle of superposition states that in undisturbed sedimentary rock layers, the oldest layers are at the bottom and the youngest are at the top. However, in a folded sequence such as a basin, the relative ages of the layers can be different. Geologists apply this principle along with structure identification to determine the relative ages of rock layers. For example, a cross-section of a syncline would show progressively younger strata towards its axis.