Why can relative dating sometimes be more precise than numerical age dating?

Relative dating can be more precise than numerical (absolute) dating because it relies on the inherent sequence of geologic events rather than the margins of error associated with isotopic measurements.1

While numerical dating provides a specific age in years, it is subject to analytical limitations. In contrast, relative dating is inherently precise because it defines the exact order of events; for example, two rock units deposited only minutes or years apart will have effectively identical numerical ages, but their relative order remains clearly defined by their physical position.1

Relative dating methods, such as the law of superposition, allow geologists to determine the sequence of events through simple visual observations and logical deductions, such as identifying which rock layer lies at the bottom of a sequence or observing crosscutting relationships where one feature, like a dike, clearly interrupts another. Because these methods do not require complex analytical equipment, they serve as an essential foundation for geochronology, helping geologists identify the most favorable units for subsequent numerical dating.12