If the polarity zones can be unambiguously identified, they constitute a precise temporal framework for sedimentary or volcanic sequences. Such records have proved invaluable for correlating stratigraphic information on a global basis and are the primary means of calibrating the Cenozoic evolutionary record with respect to time. As with paleomagnetic poles, there are criteria for reliability that must be met in order to judge a given magnetostratigraphic section. Consistency of data from multiple samples taken from a given stratigraphic level is very helpful. A minimum of three separately oriented samples from a given site is desirable.
Field tests establishing the age of the magnetization relative to the rock formation are desirable.
Some independent estimation of the approximate age of the sequence is a must. The better this is, the more confident we are in a given interpretation. Finally, the magnetostratigraphic pattern should match the time scale as interpreted. Few polarity zones should be ignored either in the section or in the time scale. Ideally, each polarity zone should be based on multiple sites in the section.