Changes in Sediment Accumulation Rate in an Oxbow Lake Following Late 19th Century Clearing of Land for Agricultural Use: A 210Pb, 137Cs, and 14C Study in Mississippi, USA
Issue Date
2004-01-01Keywords
absolute agealkali metals
Belzoni Mississippi
C 14
carbon
Cenozoic
cesium
chronostratigraphy
cores
Cs 137
dates
deforestation
Holocene
human activity
Humphreys County Mississippi
isotopes
lead
metals
Mississippi
paleoenvironment
paludal environment
Pb 210
Quaternary
radioactive isotopes
sedimentation
sedimentation rates
sediments
Sky Lake
terrestrial environment
United States
upper Holocene
Metadata
Show full item recordCitation
Davidson, G. R., Carnley, M., Lange, T., Galicki, S. J., & Douglas, A. (2004). Changes in sediment accumulation rate in an oxbow lake following late 19th century clearing of land for agricultural use: a 210Pb, 137Cs, and 14C study in Mississippi, USA. Radiocarbon, 46(2), 755-764.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
Sediment cores were collected from 2 sites in the forested fringe of an oxbow lake surrounded by land that was converted from forest to agricultural use in the late 19th century. The 2 sampling areas were selected to represent areas of high (West site) and low (east site) current sediment accumulation rates, based on distance from a perennially discharging stream. Modern (post settlement and land clearing) sediment accumulation rates were calculated using 210Pb and 137Cs on bulk sediment samples from 2 cores from each site. Two additional cores were collected from each site for radiocarbon analysis of twig cellulose with the assumption that most twigs in the sediment within the forested fringe fell from overhead and are contemporaneous with the sediment. Only the West site, however, yielded sufficient identifiable twig material for analysis. Modern sediment accumulation rates based on 210P and 137Cs fall between 0.2-0.4 cm/yr at the East site, and 0.7-1.3 cm/yr at the West site (nearest the stream inlet), with approximate agreement between the 210Pb and 137Cs methods. Modern sediment accumulation rate based on bomb-pulse 14C activity of twigs from cores from the West site is approximately 1.0 cm/yr, in agreement with the 210Pb and 137Cs results results. Historic sediment accumulation rates were estimated at the West site using twigs from deeper intervals with pre-bomb 14C activity. Sediment covering approximately 1000 yr of pre-settlement sediment accumulation exhibited evidence of minor bioturbation or in-washing of reworked material, but with a clearly lower accumulation rate of less than 0.1 cm/yr.Type
Proceedingstext
Language
enISSN
0033-8222ae974a485f413a2113503eed53cd6c53
10.1017/S0033822200035797