Activities of radionuclides in the 238U (230Th, 226Ra, 210Pb) and 232Th (232Th, 228Th, 228Ra) decay series were determined in sediments from an east Texas watershed and examined with isotope ratios and compared to particulate organic carbon (POC), % fines (< 63 μm) and total concentrations of Al, Fe and Mn. The objective was to elucidate the presence or absence of relationships affecting the effectiveness of these radionuclides in modeling sediment transport. Strong positive correlations were observed between radionuclides and Mn (Th) and % fines (Ra and Th). Isotope ratios effectively reduce these influences, supporting the contention that isotope ratios offset extrinsic variability in terrestrial sediments. Strong associations of 210Pbxs (excess 210Pb) and 226Ra/230Th with POC agree with data from marine and terrestrial settings, indicating that the role of POC in isotope fractionation, transport and sequestration merits further investigation.
|Number of pages||18|
|Journal||Journal of Environmental Radioactivity|
|State||Published - 2003|
Bibliographical noteFunding Information:
Funding provided by the Texas Water Development Board, Texas Water Resources Institute, Geological Society of America, The Gulf Coast Association of Geological Sciences, Texas A&M University and the Texas Institute of Oceanography is gratefully acknowledged. Cooperation of numerous landowners in allowing access to field sites is also appreciated. Thanks are also extended to Mr. Chris Courtney for assisting in both field and laboratory work and Ms. M. Michaele Cerf for laboratory assistance and to the three anonymous reviewers for contributing to the improvement of this manuscript.
ASJC Scopus subject areas
- Environmental Chemistry
- Waste Management and Disposal
- Health, Toxicology and Mutagenesis