碩士 / 國立中山大學 / 海洋地質及化學研究所 / 91 / Abstract
The South China is the largest marginal sea in the western Pacific. It’s unique geographic settings and high sedimentation rates preserve the paleo- climatic signals with larger amplitude than those from the open ocean. In this study, grain size and elemental compositions of the fine fractions (<63 mm) from the sediments collected by the ODP Leg 184 Sites 1143 and 1146 were analyzed to reconstruct the depositional settings for the last 8 My.
Particle size and elements analyses, in conjunction with the carbonate contents and sedimentation rates from core sediments, reflect the possible increase in precipitation, which was caused by the strengthened summer monsoon between 5 and 3 Ma. In addition to the grain sizes change from silt-domain to clay-domain, Ti/Al ratio of sediments increase while the Si/Al, Zr/Al, and K/Al ratios decrease, which could be related to the enhanced sediments input through rivers. These environmental changes could be attributed to the uplift of Tibet plateau and the formation of Western Pacific Warm Pool. On the contrary, the impact of climate changes is not evident in the loess plateau in the northwestern China. It is likely that the climate in the South China Sea became warm and humid from 5 to 3 Ma were regional changes.
Key words: Grain size, element analyses, South China Sea, summer monsoon
| Identifer | oai:union.ndltd.org:TW/091NSYS5271004 |
| Date | January 2003 |
| Creators | Sheng-Yuan Yang, 楊盛淵 |
| Contributors | Hui-Ling Lin, 林慧玲 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 127 |
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