Tracing the Provenance of Modern Galveston Sediments Using Strontium and Neodymium Isotopes and Major and Trace Elemental Abundances

Galveston Bay is a semi-enclosed coastal embayment, located on the southeastern shore of Texas adjacent to the Greater Houston Metropolitan Area. The Houston Ship Channel (HSC) through Galveston Bay provides many industries access to the Gulf of Mexico. The project provides the first strontium (Sr) and neodymium (Nd) isotope ratios for Galveston Bay, as well as updated major and trace element concentrations for Galveston Bay sediments. Procedures and methods used in this study include leaching and acid digestions of sediments for sample residues, aliquot separations, dilution of major and trace element aliquots in ~2% HNO3 solution for ICP-MS and ICP-OES analyses, and column chemistry (2) extraction of Sr and Nd isotope aliquots for TIMS analyses. The range of εNd values, -14.21 to -10.15, in this dataset suggests recycled crustal material and/or an older source (McCulloch and Wasserburg, 1978). Rare earth element (REE) contents of Galveston Bay residues resemble quartz arenites from the North American midcontinent region, which have REE contents 10–100 times lower than bulk igneous rocks from Archean and Proterozoic source (Johnson and Winter, 1999). The Trinity Bay contribution, of fine-grained, clay- and silt-size fractions, of suspended sediments entering the bay, is greatest in Galveston Bay, and is the most prevalent pattern seen in spatial variation maps of fRb/Sr values and high field strength elements (HFSE).