Evaluating Estuarine Sediment Provenance from Geochemical Patterns in Upper Chesapeake Bay
Russ, E; Palinkas, C; Cornwell, J
Geochemical patterns in upper Chesapeake Bay sediments can reflect a variety of important processes. Spatial and down-core geochemical patterns are useful for understanding the underlying conservative (sediment provenance) and non-conservative (salinity, redox, anthropogenic influences) processes driving these patterns. Distinguishing conservative and non-conservative processes to quantify sediment sources will help develop management strategies to limit excess sedimentation in estuaries. In this study, elemental concentrations were measured via inductively coupled plasma mass spectroscopy (ICP-MS) and analyzed using principal component analysis. The sediment geochemistry data were then analyzed to evaluate contributions of Susquehanna River and shoreline erosion to bottom sediments in the upper Bay using a sediment-provenance analysis. Elements associated with aluminosilicate minerals, which were sensitive to grain-size changes, and rare earth elements, which were sensitive to salinity changes, explained the most variability in the dataset. Variability in heavy metal concentrations demonstrated decadal changes in anthropogenic inputs. The results from the sediment-provenance analysis indicated that the Susquehanna River is the dominant source of fine sediment in the upper Bay.
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