Issue Date
2004-01-01Keywords
absolute agealkali metals
C 14
calibration
carbon
cesium
combustion
cores
corrections
Cs 137
Grenada County Mississippi
Grenada Lake
isotopes
lacustrine environment
lake sediments
metals
methods
Mississippi
modern
radioactive isotopes
sample preparation
sediments
United States
Yalobusha County Mississippi
Metadata
Show full item recordCitation
McGeehin, J., Burr, G. S., Hodgins, G., Bennett, S. J., Robbins, J. A., Morehead, N., & Markewich, H. (2004). Stepped-combustion 14C dating of bomb carbon in lake sediment. Radiocarbon, 46(2), 893-900.Journal
RadiocarbonDescription
From the 18th International Radiocarbon Conference held in Wellington, New Zealand, September 1-5, 2003.Additional Links
http://radiocarbon.webhost.uits.arizona.edu/Abstract
In this study, we applied a stepped-combustion approach to dating post-bomb lake sediment from north-central Mississippi. Samples were combusted at a low temperature (400 degrees C) and then at 900 degrees C. The CO2 was collected separately for both combustions and analyzed. The goal of this work was to develop a methodology to improve the accuracy of 14C dating of sediment by combusting at a lower temperature and reducing the amount of reworked carbon bound to clay minerals in the sample material. The 14C fraction modern results for the low and high temperature fractions of these sediments were compared with well-defined 137Cs determinations made on sediment taken from the same cores. Comparison of "bomb curves" for 14C and 137Cs indicate that low temperature combustion of sediment improved the accuracy of 14C dating of the sediment. However, fraction modern results for the low temperature fractions were depressed compared to atmospheric values for the same time frame, possibly the result of carbon mixing and the low sedimentation rate in the lake system.Type
Proceedingstext
Language
enISSN
0033-8222ae974a485f413a2113503eed53cd6c53
10.1017/S0033822200035931