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14C Depth Profiles as Indicators of Trends of Climate and 14C/12C Ratio

Published online by Cambridge University Press:  18 July 2016

Robert H Brown
Robert H Brown*
Affiliation:
Geoscience Research Institute, Loma Linda University, Loma Linda, California 92350
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Abstract

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Composite curvature averages for 14C age depth profiles of deep ocean sediment, continental sediment, and soil each indicate a global trend for 14C age increment per cm depth to increase with 14C age over the range for which a definitive statistical sample is available. The global trend indicated for peat profiles is constant 14C age increment per cm depth over the past 10,000 14C yr. Correlation coefficients between changes in 14C yr/cm and maximum profile thickness contradict compaction as an adequate explanation for the global trend indicated by sediment and soil profiles. This trend must be explained by additional factors such as progressively decreasing contamination from older carbon, increasing cosmic ray intensity, decreasing geomagnetic intensity, diminishing 12C in the active biosphere during profile accumulation, and climate factors affecting the rate of accumulation. The diverse trend of peat profiles may indicate climatic conditions more favorable to peat growth during the earlier portion of the past 10,000 yr.

Type
III. The Carbon Cycle
Information
Radiocarbon , Volume 28 , Issue 2A , 1986 , pp. 350 - 357
Copyright
Copyright © The American Journal of Science 

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