碩士 / 國立臺灣海洋大學 / 地球科學研究所 / 106 / Late Quaternary terrestrial environment reconstructions in Taiwan were mostly used palynology and geochemical proxies; however, diatom assembly was used rarely for paleo-environmental reconstructions. In this study, we used multi-proxy methods, including diatom, grain size and Itrax-XRF elemental analysis from a lacustrine sediment core (TLM-1) which was drilled from the littoral side of an alpine lake, Tunlumei Pond (TLM), at Nantou County of central Taiwan. For the diatom analysis, diatom valves were only preserved in upper 95 cm of the core TLM-1, and 34 genera and 83 species of fossil diatoms were identified. On the basis of cluster analysis, four diatom biostratigraphy zones were recognized. Concurrently, the occurrence of diatom valves and the increasing of wetland pollen suggested that the TLM water level attended to the present condition since 750 cal BP. During 750-610 cal. BP, the planktonic species S. pinnata increased, indicating the water level rose. Then, during 610-540 cal. BP, benthic species increased, indicating the water level declined. During 540-470 cal. BP, acidophilous diatom Eunotia intermedia presented a remarkable increase, which may link with frequent hydrological disturbances, such as typhoon or heavy rainfall events. Since 470 cal. BP, S. pinnata was continued to be dominant, indicating the stable aquatic environment as today. Due to the small catchment area of TLM, the large grain sets should be caused by heavy rainfall. Thus, there might have four heavy rainfall periods at approximately 550-450 cal. BP, 1050-950 cal. BP, 1550-1450 cal. BP, and 2200-2100 cal. BP.
| Identifer | oai:union.ndltd.org:TW/106NTOU5135004 |
| Date | January 2018 |
| Creators | Tang, Zih-Wei, 唐子惟 |
| Contributors | Chen, Huei-Fen, Wang, Liang-Chi, 陳惠芬, 汪良奇 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 59 |
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