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Presenters Notified: November 2012

Program Schedule Posted:November 2012

Abstracts Available: January 2013

Meeting:
17-22 February 2013

Mayo, M., University of South Florida, USA, mmayo@mail.usf.edu
Smoak, J. M., University of South Florida St. Petersburg, USA, smoak@mail.usf.edu
Smith, C., US Geological Survey, USA, cgsmith@usgs.gov
Fanning, K., University of South Florida, USA, kaf@marine.usf.edu
Smith, T. J., US Geological Survey, USA, tom_j_smith@usgs.gov

A COMPARISON OF URANIUM BUDGETS FOR ESTUARINE WETLANDS OF THE EVERGLADES NATIONAL PARK, FLORIDA AND MOBILE BAY, ALABAMA

Investigations of subsurface-uranium dynamics in carbonate-dominated estuarine wetlands are rare in comparison to analogous siliciclastic systems. Understanding how these different geologic environments influence uranium-cycling may better constrain the global uranium-budget. To address this deficiency, we compare uranium and trace metal concentrations in sediment cores consisting of highly organic carbonate muds from the Shark River Slough (SRS), located within Everglades National Park, and siliciclastic salt marsh sediments from Mobile Bay. Sediment was digested using a laboratory microwave (EPA-protocol 3051A) and extracted uranium, barium, iron, manganese and strontium were measured by inductively coupled plasma-mass spectrometry (ICP-MS). Results for two SRS cores indicate that the mean uranium concentration was of 11.88 ppm, well above the mean concentration of 6.08 ppm in Mobile Bay. Increasing downcore uranium concentrations in SRS correlate with higher organic matter percentages with depth, while samples in Mobile Bay indicate that the highest uranium concentrations are found in the top 5 cm. While both sites have reducing conditions, differences in dissolved inorganic carbon may best explain the difference in uranium at the two sites.

Oral presentation

Session #:SS25
Date: 2/22/2013
Time: 15:15