| Инд. авторы: | Chen J., Li J., Tian S., Kalugin I., Darin A., Xu S. |
| Заглавие: | Silicon isotope composition of diatoms as a paleoenvironmental proxy in Lake Huguangyan, South China |
| Библ. ссылка: | Chen J., Li J., Tian S., Kalugin I., Darin A., Xu S. Silicon isotope composition of diatoms as a paleoenvironmental proxy in Lake Huguangyan, South China // Journal of Asian Earth Sciences. - 2012. - Vol.45. - P.268-274. - ISSN 1367-9120. - EISSN 1878-5786. |
| Внешние системы: | DOI: 10.1016/j.jseaes.2011.11.010; SCOPUS: 2-s2.0-84855201092; |
| Реферат: | eng: Silicon is essential for the growth of diatoms, which utilize dissolved silicic acid in lake water and form opaline silica (SiO 2·nH 2O). During the uptake of dissolved silicic acid, there is a preferential incorporation of light silicon isotope ( 28Si) into biogenic silica, resulting in the enrichment of heavy silicon isotope ( 30Si) in dissolved silicic acid. The silicon isotope composition of diatom silica (δ 30Si 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 δ 30Si diatom as an indicator of lacustrine environment, here we made the first measurements of δ 30Si diatom in the sediment core from Lake Huguangyan, a closed crater lake in China. The result shows that δ 30Si diatom varies from -0.6‰ to 1.1‰ and displays broad similarities to variations in contents of biogenic silica and organic carbon throughout the sediment core. δ 30Si diatom is a reliable paleotemperature proxy in Lake Huguangyan, which is supported by good correlation between δ 30Si diatom and available temperature records. Heavier δ 30Si diatom indicates greater dissolved silicic acid utilization at higher temperature while lighter δ 30Si diatom reflects decreased utilization at lower temperature. The most negative δ 30Si 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 2000years, 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. δ 30Si 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. © 2011 Elsevier Ltd.
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| Ключевые слова: | Bacillariophyta; Huguangyan Lake; Guangdong; China; temperature profile; temperature anomaly; silicon; silicic acid; sediment core; paleotemperature; paleoenvironment; paleoclimate; organic carbon; lacustrine environment; lacustrine deposit; isotopic composition; high temperature; diatom; climate variation; Silicon isotope; Paleotemperature proxy; Lake Huguangyan; Biogenic silica; |
| Издано: | 2012 |
| Физ. характеристика: | с.268-274 |