Time-Frequency Analysis on Palaeoclimate Recorded by Phytolith at the Late Holocene Peat Deposits in Dunhua Basin
详细信息
- 责任者：Zhang Xinrong (School of Earth Sciences ; Jilin University ; Changchun 130061 ; China) ; Fang Shi
- 刊名：Journal of Earth Sciences and Environment
- 出版年：2010
- 卷期：32(4)
- 关键词：全新世 ; Holocene ; 植物硅酸体 ; plant opal ; 古气候 ; paleoclimate ; 吉林 ; Jilin Province
- 页码：p.420-429
- 图表：8 illus., 35 refs.
- 分类号：1400
- issnNo：ISSN1672-6561
- isbnNo：CN61-1423/P
摘要
Based on Morlet one-dimensional continue wavelet transform, palaeoclimate parameters recorded by phytolith at Jixiang and Yushu profiles in Dunhua Basin were analyzed by time-frequency, change of palaeoclimat was discussed. The results showed that the wavelet spectrum and energy change at Jixiang profile with no less than 30 frequency scales were similar with that at Yushu profile with no less than 20 frequency scales, and both profiles had six different energy aggregation regions. Changes of palaeoclimate since the Late Holocene in Dunhua Basin was divided into six stages: before B.C. 730, warm and cooling period; B.C .730~B.C. 205, mild, humid, and gradually cooling period; B.C. 205~A.D. 255, warm period; A.D. 255~525, cooling period; A.D. 525~1220, warm and humid period; after A.D. 1220, a stage with more frequent fluctuations.