:::
103/12/23 14:00 台灣大學地質科學系陳文山教授 演講
演講公告
張貼人：網站管理員 ╱ 公告日期：2014-12-18演 講 公 告
主講人：陳文山 教授
地點：中央大學科學一館S-325教室
摘要：
講題：Shoreline changes of Taiwan since the Last Glacial Maximum
主講人：陳文山 教授
台灣大學地質科學系
時間：12月23日（星期二）下午2點
地點：中央大學科學一館S-325教室
摘要：
Taiwan is an interesting region for the study of neotectonics in an area containing an ongoing thrust belt and foreland basin. In particular, the active tectonics of the coastal plain around the Taiwan island is deposited 100-200 m thick of marine sediments since the postglacial marine transgression (18-6 ka). Hence, in this study we first use about 200 boreholes and radiocarbon dating data to reconstruct the stratigraphic architecture and construct the shoreline since the Last Glacial Maximum (<27,000 yr BP).
The western coastal plain is a foreland basin causing of higher rates of subsidence and sediments deposition during the Quaternary. Climate changes since the postglacial enhanced sea-level rise. Therefore the shoreline changes depend on the above three major factors of eustatic, tectonic and depositional rates. In this study, the depositional environments that have been derived from analysis of core-logging are quite well known the past 18 ka.
The coastal plains were characterized by progressive deepening due to the transgression event during the high stands of sea-level in the past 18 ka, that the shoreline displayed landward shift ranged from 1-5 m/yr. The highest transgressive rate was about 3-5 m/yr in the Chianan Coastal Plain, which resulted from the lower gradient of geomorphic features. Eustatic sea level has not varied much during the past 6 ka. Therefore the sediments were progressively filled in the coastal plain cause of the depositional accommodation decrease, and that the shoreline shown seaward shift. The regressive rate of shoreline ranged from 0.5-5 m/yr. The highest regressive rate was about 5 m/yr in the Pingtung Coastal Plain resulting from higher depositional rate.
附加檔案：
最後修改時間：2015-03-05 PM 5:07
