thumbnail

Accuracy of post-bomb 137Cs and 14C in dating fluvial deposits

Quaternary Research

By:
, ,
DOI: 10.1016/0033-5894(92)90056-O

Links

Abstract

The accuracy and precision of 137Cs and 14C for dating post-1950 alluvial deposits were evaluated for deposits from known floods on two rivers in Arizona. The presence of 137Cs reliably indicates that deposition occurred after intensive above-ground nuclear testing was initiated around 1950. There was a positive correlation between the measured level of 137Cs activity and the clay content of the sediments, although 137Cs was detected even in sandy flood sediments with low clay content. 137Cs is a valuable dating tool in arid environments where organic materials for 14C or tree-ring dating are scarce and observational records are limited. The 14C activity measured in different types of fine organic detritus yielded dates within 1 to 8 yr of a 1980 flood deposit, and the accuracy was species-dependent. However, undifferentiated mixtures of fine organic materials from several post-bomb deposits of various ages repeatedly yielded dates between 1958 and 1962, and detrital charcoal yielded a date range of 1676-1939. In semiarid environments, the residence time of most types of organic debris precludes accurate annual resolution of post-bomb 14C dates. ?? 1992.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Accuracy of post-bomb 137Cs and 14C in dating fluvial deposits
Series title:
Quaternary Research
DOI:
10.1016/0033-5894(92)90056-O
Volume
38
Issue:
2
Year Published:
1992
Language:
English
Publisher:
Elsevier
Publisher location:
Amsterdam, Netherlands
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Quaternary Research
First page:
196
Last page:
204
Number of Pages:
9