Issue Date
1980-01-01Keywords
genesissoils
organic compounds
organic materials
methods
C 14
carbon
isotopes
radioactive isotopes
absolute age
geochemistry
Metadata
Show full item recordCitation
Gilet-Blein, N., Marien, G., & Evin, J. (1980). Unreliability of 14C dates from organic matter of soils. Radiocarbon, 22(3), 919-929.Publisher
American Journal of ScienceJournal
RadiocarbonDescription
From the 10th International Radiocarbon Conference held in Bern, Switzerland and Heidelberg, Germany, August 19-26, 1979.Additional Links
http://radiocarbon.webhost.uits.arizona.edu/Abstract
Contamination by recent carbon and the turnover of organic matter make dating of ancient soils difficult. In order to isolate the oldest organic fraction of sediments, two main extraction methods were previously proposed: 1) alkaline solubilization of humus that separates humins, humic acids, and fulvic acids, and 2) successive hydrolyses that solubilize increasingly resisting products. Both preparation methods were tested on the same actual or fossil soils of different pedologic types from five geologic profiles on which other chronologic data are available. Analytic results show that 14C ages obtained from alkaline extraction products differ according to the duration of treatments and characteristics of soils: while hydrolysis should yield more homogeneous results and isolate oldest fractions. It seems likely that true ages of geologic formations were never obtained from their organic matter and that the oldest organic fraction, contemporaneous with the sediment formation, completely disappears. Thus, most ages from 14C dating of organic matter of soils must be too recent.Type
Proceedingstext
Language
enISSN
0033-8222ae974a485f413a2113503eed53cd6c53
10.1017/S0033822200010328