Variations in radiocarbon ages of various organic fractions in core sediments from Erhai Lake, SW China

Xu, S. and Zheng, G. (2003) Variations in radiocarbon ages of various organic fractions in core sediments from Erhai Lake, SW China. Geochemical Journal, 37(1), pp. 135-144.

Abstract

Radiocarbon dating was performed for the extracted organic fractions (cellulose-rich and humic acid fractions of plant fragment; fulvic acid, humic acid and humin fractions of humus substance) and shell from core sediments of the Erhai Lake, SW China. The C-14 dating results reveal that there are considerable differences, but there apparently is a humic acid less than or equal to humin < fulvic acid fraction sequence of C-14 age increase. The variability in radiocarbon ages of organic fraction of lake sediment suggests that special caution is necessary when radiocarbon ages of bulk sediments are used. The linear correlation between C-14 age of allochthonous terrestrial macrofossil (plant fragment and shell) and depth indicates roughly a constant sedimentation rate of ca. 0.7 rum yr(-1) in central Erhai Lake since 4500 yr BP. The C-14 ages of the autochthonous humic acid fraction are 210similar to4800 yr shift from "the true C-14 age" obtained by interpolating the corresponding horizontal level to the above C-14 age-depth correlation. Such age difference may be alternatively attributed to a uniform reservoir effect (most likely ca. 300 yr). The period with large C-14 age shift synchronizes with the period of changes in (delta(13)C and ARM intensity and ARM/susceptibility values.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Xu, Dr Sheng
• Authors: Xu, S., and Zheng, G.
• Subjects: Q Science > QE Geology
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Geochemical Journal
• Publisher: Terrapub
• ISSN: 0016-7002
• Copyright Holders: Copyright © 2003 Terrapub
• First Published: First published in Geochemical Journal 37(1):135-144
• Publisher Policy: Reproduced with the permission of the publisher