APPROACHES TO CHARACTERIZING AND COMPARING STRATIGRAPHIC CORRELATIONS, AS APPLIED TO ESTIMATION OF BIODIVERSITY

Several approaches to incorporating information about fossil recovery into estimates of extinction and origination rates are available. Successful implementation of these methods requires a robust and reliable method of creating composite sections, and of mapping presence/absence data from horizons within individual sections into a composite.This composited data consolidates occurrence information from these various sections into a single estimate of species ranges and occurrences. Composite sections formed by graphic correlation and by automated methods such as constrained optimization by simulated annealing (CONOP) may produce slightly different composite section solutions, and have varying levels of reliability. We present here several possible criteria for comparison of composite section solutions, and to estimating the robustness of these solutions using the extensively studied graptolite fauna of the late Ordovician, including collections from the Yangtze region of China and Vinnini Creek, Nevada, as a case study.