49 Geochemistry (Posters)

Tuesday, 20 March 2012
8:00 AM - 12:00 PM
Ballrooms A, B & C and Ballroom Pre-function Area

THE GREAT BAY ESTUARY SYSTEM OF NEW JERSEY; A RARE EARTH ELEMENT (REE) ANALYSIS

Paper number: 49-9
Program: Technical Sessions
Time: 8:00 AM – 12:00 PM

Authors

Abstract

Fossil vertebrates (bioapatite) provide evidence of biological evolution, biostratigraphic, paleoenvironmental, and taphonomic information significant to interpretations of the geologic and paleoenvironmental history. Rare Earth Elements (REE) and Trace Element (TE) signatures and associated ratios reflect the geochemical conditions during the stabilization of the bioapatite. During the fossilization process, the bone material act as “flight recorders”, incorporating unique elemental signatures of the environment. The incorporation of REE into the bioapatite allows us to use modern waters as a template for past environments. With these REE signatures in fossil vertebrates, we have developed techniques to interpret the paleoenvironment.

A broad understanding of the conditions during diagenesis has been investigated, however little information exists concerning quantitative comparison of the signatures of fossil bioapatite to modern ocean chemistries and organisms under various conditions. The dynamic geochemical variations in estuaries provide an opportunity to investigate the REE geochemistry in a variety of salinities and redox conditions. Major and REE, were analyzed from water samples takes in Great Bay Estuary, New Jersey, between the mouth of Nacote Creek and West Tucker Island. Our research compares REE signatures in high salinity environments, fresh water and the fresh water/marine water interface within the estuaries. The pH and redox of the waters, as well as other factors control the REE concentrations; therefore this provides the template to interpret the original paleoenvironmental conditions during the fossilization process.