The use of faunal gradient analysis for intraregional correlation and assessment of changes in sea-floor topography in the type Cincinnatian

In paleobiology and stratigraphy, there is a growing need to develop high-resolution chronostratigraphic frameworks at regional scales, which would permit unprecedented assessments of spatiotemporal variation in preserved biotas. Here, we present an intraregional correlation for the Kope and lower Fairview Formations of the type Cincinnatian, on the basis of detrended correspondence analysis (DCA) of faunal census data; we believe that the method also holds promise as a tool of correlation in other fossiliferous venues. The data were collected directly in the field at closely spaced stratigraphic intervals but with relatively coarse taxonomic and quantitative data resolution. This approach is independent of lithologic assessments and does not require the delineation of sequence stratigraphic architecture in the study area. Faunal curves were constructed for each locality on the basis of stratigraphic changes in sample scores for DCA axis 1; the curves were smoothed to reveal a long-term signal of paleoenvironmental change recognizable at all localities. Several inflections on the curves provided lines of correlation from locality to locality. Moreover, comparisons of sample scores among three of the localities suggested notable changes through time in the relative paleoenvironmental attributes of locations arrayed across the Cincinnatian paleoramp, indicating that the sea floor was spatiotemporally dynamic.