Abstract
Analyses of the total alpha radioactivity distribution in 31 North Pacific manganese nodules yield an average growth rate of 6.8 (±2) mm/m.y. Samples from a single box core show almost identical total activity vs. depth profiles, regardless of nodule size or shape. A characteristic feature of many nodules examined is an apparent change (steepening) in slope of the alpha activity profile between depths of 0.5–1.5 mm. This feature may reflect a fundamental feature of nodule growth, possibly mobility of 230Th or its daughters in a regular way, interrupted growth, or nodule turnover. Near-surface decreases in total alpha activity probably result from 226Ra loss.
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© 1979 Plenum Press, New York
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Macdougall, J.D. (1979). The Distribution of Total Alpha Radioactivity in Selected Manganese Nodules from the North Pacific: Implications for Growth Processes. In: Bischoff, J.L., Piper, D.Z. (eds) Marine Geology and Oceanography of the Pacific Manganese Nodule Province. Marine Science, vol 9. Springer, Boston, MA. https://doi.org/10.1007/978-1-4684-3518-4_25
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DOI: https://doi.org/10.1007/978-1-4684-3518-4_25
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