Silicon isotope composition of diatoms as a paleoenvironmental proxy in Lake Huguangyan, South China

	Silicon isotope composition of diatoms as a paleoenvironmental proxy in Lake Huguangyan, South China
	Jingan Chen; Jian Li; Shihong Tian; Ivan Kalugin; Andrey Darin; Sheng Xu
	2012
发表期刊	Journal of Asian Earth Sciences
卷号	45 期号:2 页码:268-274
摘要	Silicon is essential for the growth of diatoms, which utilize dissolved silicic acid in lake water and form opaline silica (SiO2 center dot nH(2)O). During the uptake of dissolved silicic acid, there is a preferential incorporation of light silicon isotope (Si-28) into biogenic silica, resulting in the enrichment of heavy silicon isotope (Si-30) in dissolved silicic acid. The silicon isotope composition of diatom silica (delta Si-30(diatom)) may thus record changes in the percentage utilization of dissolved silicic acid by diatoms, which can be then related to other aspects of climate/environment. With the aim of exploring the potential of delta Si-30(diatom) as an indicator of lacustrine environment, here we made the first measurements of delta Si-30(diatom) in the sediment core from Lake Huguangyan. a closed crater lake in China. The result shows that delta Si-30(diatom) varies from -0.6 parts per thousand to 1.1 parts per thousand and displays broad similarities to variations in contents of biogenic silica and organic carbon throughout the sediment core. delta Si-30(diatom) is a reliable paleotemperature proxy in lake Huguangyan, which is supported by good correlation between delta Si-30(diatom) and available temperature records. Heavier delta Si-30(diatom) indicates greater dissolved silicic acid utilization at higher temperature while lighter delta Si-30(diatom) reflects decreased utilization at lower temperature. The most negative delta Si-30(diatom) values in the sediment core occur between AD 1580 and 1920, which suggests AD 1580-1920 was the coldest period in Lake Huguangyan over the past 2000 years, thus providing evidence for the existence of the LIA in tropical South China. There are few means by which to reconstruct the history of temperature changes in tropical terrestrial region. delta Si-30(diatom), in this study, has proven to be a new promising paleotemperature proxy in lacustrine sediments, and may play important role in reconstructing past temperature changes at low latitude in the future. Detailed investigations on the silicon isotopes of diatoms in more lakes would be desirable in further research.
关键词	Silicon Isotope Biogenic Silica Paleotemperature Proxy Lake Huguangyan
学科领域	环境地球化学
收录类别	SCI
语种	英语
文献类型	期刊论文
条目标识符	http://ir.gyig.ac.cn/handle/352002/4875
专题	环境地球化学国家重点实验室_环境地球化学国家重点实验室_期刊论文
推荐引用方式 GB/T 7714	Jingan Chen,Jian Li,Shihong Tian,et al. Silicon isotope composition of diatoms as a paleoenvironmental proxy in Lake Huguangyan, South China[J]. Journal of Asian Earth Sciences,2012,45(2):268-274.
APA	Jingan Chen,Jian Li,Shihong Tian,Ivan Kalugin,Andrey Darin,&Sheng Xu.(2012).Silicon isotope composition of diatoms as a paleoenvironmental proxy in Lake Huguangyan, South China.Journal of Asian Earth Sciences,45(2),268-274.
MLA	Jingan Chen,et al."Silicon isotope composition of diatoms as a paleoenvironmental proxy in Lake Huguangyan, South China".Journal of Asian Earth Sciences 45.2(2012):268-274.

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