Patterns of time-averaging in the shallow marine fossil record

Abstract

Virtually all paleontologic and historical geologic interpretations require information on the time resolution of individual samples. For relatively broad segments of the record such as facies tracts and entire basins, a variety of approaches can be used to determine the relative and absolute duration of a “sample”. For finer subdivisions, however, such as individual beds and assemblages that are within the error-bars of radiometric dates or within the span of a biostratigraphic zone, estimating elapsed time per unit becomes far more difficult. Assessing time at this scale is important, however, because this is the usual sampling interval for autecologic, synecologic, morphometric, and species-level biostratigraphic and evolutionary studies.