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44548-B8
A Composite Standard Biostratigraphic Database for Assessing Rates of Foraminiferal Origination and Extinction During the Late Paleozoic Ice Age

John R. Groves, University of Northern Iowa

The objective of this project is to develop a composite standard database for assessing rates of foraminiferal origination and extinction during the Late Paleozoic ice age. A composite standard database is a compilation of species' stratigraphic ranges achieved by graphically correlating biostratigraphic data from multiple localities. The first year of the grant was devoted to acquisition of data, formatting data files, and graphically correlating the data files to produce a preliminary composite standard. A total of 60 data files were constructed and quality-checked on the basis of both published and unpublished sources. All 60 files now have been graphically correlated against the composite standard using GraphCor© software. This has resulted in a database consisting of the oldest and youngest known stratigraphic occurrences of 1,698 species of foraminifers, conodonts, palynomorphs and certain megafossils. The sequence of occurrences was calibrated relative to absolute time (Ma) by linear interpolation between stage boundary dates published by the International Commission on Stratigraphy. The 60 data files are being compiled independently using the constrained optimization technique (CONOP). The second year of the grant will be devoted to comparing the results generated by graphic correlation and constrained optimization. Both compilations will be used to estimate origination and extinction rates, lineage durations and diversity trends for Late Paleozoic pre-glacial, glacial and post-glacial intervals.

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