¹⁴C GEOCHRONOLOGY AND RADIOCARBON RESERVOIR EFFECT OF REVIEWED LAKES STUDY IN CHINA

Abstract

Lacustrine sediments are important archives for paleoclimate research, but there are evident carbon reservoir effects. Radiocarbon (14C) ages of lake sediments must be corrected for these effects before applying them to paleoclimate research. The authors review the lacustrine research from the last 20 years from different climatic regions in China, and systematically investigate the 14C age and correction methods used in the studies of 81 lakes. It is found that the climate-vegetation cover and distribution of carbonate around lakes are dominant factor controlling radiocarbon reservoir effects. In eastern China, the average 14C reservoir age is about 500 14C years and is associated with relatively dense vegetation. However, in northwest China and Qinghai-Tibet Plateau, widespread carbonate bedrock may markedly increase the radiocarbon reservoir age which frequently is about 1500 and 2500 14C years. A piecewise linear regression model provides more reliable 14C reservoir age correction that accounts for sedimentary facies and sedimentation rate changes. It is worth mentioning that when analyzing 14C ages deviated greatly from time sequence, the age anomalies may indicate important effects relevant to the study of climate and environmental changes.

Hydro-climatic aspects of prehistoric human dynamics in the drylands of the Asian interior

“…Although radiocarbon dating of total organic carbon (TOC) has limitations in application to dating lake sediments of arid central Asia (e.g. Xinjiang and Tibetan Plateau) (Hou et al, 2012; Zhang et al, 2012; Zhou et al, 2022), previous Holocene climate reconstructions based on sediment sequences of western and southern Tarim Basin showed that the bulk TOC could yield 14 C dates generally in stratigraphic order (Shu et al, 2018; Zhao et al, 2012; Zhong et al, 2007; Tang et al, 2009). Five samples of bulk sediment from the YC section were thus used for accelerator mass spectroscopy (AMS) radiocarbon dating, which was conducted by Beta Analytic Inc., USA (Table 1).…”

Anthropogenic origin of a change in the fire-climate relationship in northern China after ∼2000 yr BP: Evidence from a 15,500-year black carbon record from Dali Lake

“…Several estimates have been made of the size of the carbon reservoir in the lacustrine sediments of Dali Lake, with estimated reservoir ages of 611 years (Xiao et al, 2008(Xiao et al, , 2009Liu et al, 2016a), 472 years (Fan et al, 2016(Fan et al, , 2017(Fan et al, , 2019Wen et al, 2017), and 0 years (Liu et al, 2016b;Goldsmith et al, 2017). In this study we calculated the reservoir age in different core intervals according to the sediment accumulation rate and the 14 C ages of terrestrial plant residues (Zhou et al, 2021). The corrections were then applied to establish a new chronological framework for core DL19B (see Section 4.1 for details).…”

Soil Erosion Caused the Increasing Holocene Radiocarbon Reservoir Effect of Lake Kanas in the Altai Mountains

“…The old carbon usually results from the following factors: disequilibrium in the 14 C exchange between water and the atmosphere, which leads to lower 14 C concentrations in the lake water (Druffel et al 1983); the influx of groundwater or surface runoff from watersheds with a limestone substrate, which introduces pre-aged carbon (Olsson 2009); biological utilization of dissolved inorganic carbon (DIC) in the lake water (Kwiecien et al 2008); an inherited reservoir effect from the introduction of sediments from the watershed (Frueh et al 2012); and the variable contribution of old terrestrial organic material eroded from catchment soils (Blaauw et al 2011). The lake 14 C reservoir effect varies between different geographical units and over time (e.g., Hou et al 2012; Mischke et al 2013; Zhou et al 2014, 2021; Zhou et al 2015; Chen et al 2019; Zhou et al 2020), and assessing the reservoir effect is a priority in the 14 C dating of TOC and aquatic plant remains, to establish an accurate chronological framework for lake sediments.…”