| Summary: | The purpose of this project was to use the stratigraphic range data of two extinct marine micro-fossil groups, conodonts and graptolites, to construct a composite range chart and correlation model for Ordovician age strata in Argentina and Newfoundland. These two locations were part of the eastern portion of the paleo-continent Laurentia. The goal was to integrate range data from organisms that occur in different rock types, limestones and shales, using computer-assisted graphic correlation techniques. Graphic correlation is the comparison of specific rock units by the presence of similar fossils found within them using a bi-variate plot and line of correlation. It is used to find a better estimate of the fossil duration in the earth’s history. The end result is a composite range chart, which shows the composite range of the organism in comparison to a timescale. The composite range chart constructed from the Ordovician rocks of Argentina and Newfoundland was used to answer questions on the viability of using CONOP9 to compare two different bio-facies. This research is important because the composite range chart provides paleontologists with a tool for studying and dating the rock record. Better estimates of fossil ranges can be used to make the geologic timescale more precise.
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