晚第四紀以來台北盆地沉積物的組成特性

Late Quaternary sediments composition of the Taipei Basin

林佩儀(Pei-Yi Lin)

指導教授 ： 陳文山

國立臺灣大學/理學院/地質科學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.02766

摘要

為了了解台北盆地之地下地質與沉積物來源的變化情形，本研究重新進行十三口的岩芯紀錄。由岩芯沉積物組成的研究與來源區地層之岩性比對，可分析各來源地質區的沉積物在台北盆地地下地質的垂直與側向上的分布情形。同時蒐集過去與新測的定年資料，可建立一時間的架構，有助於進一步探討與說明台北盆地的沉積物來源變化情形。
台北盆地沉積物大都來自盆地周圍的大小河系，以現今流入台北盆地的河流系統來看，大漢溪、新店溪及基隆河為主要河流，其餘則為發育於大屯火山、林口台地及周圍西部麓山帶的小河流。新店溪(及大漢溪)流域與基隆河流域出露的岩層有很大的差異性，新店溪(及大漢溪)流域涵蓋中新世沉積岩與始新世-漸新世的輕度變質岩，而基隆河流域僅涵蓋中新世沉積岩，兩河流沉積物組成有很大的差異。基隆河的砂質沉積物以石英為主，新店溪的沉積物除了含較少量的石英之外，同時含有大量的變質岩屑與硬頁岩岩屑；盆地北側大屯火山流域的火成岩岩屑與盆地西側林口台地的大量變質岩屑與極少量硬頁岩岩屑，各地質區的沉積物有不同的岩屑比例。
研究分析結果顯示盆地東北側基隆河流域的松山地區大致上以石英砂沉積物為主；新店溪流域鑽井沉積物以硬頁岩岩屑與變質砂岩岩屑為主；位於盆地邊緣的井，沉積物來源受井周圍的河流影響而有交替性的變化情形。

關鍵字

第四紀 ； 台北盆地 ； 岩芯 ； 沉積物

並列摘要

In order to understand the underground architecture of the Taipei Basin, thirteen drill cores acquired from the Taipei Basin were studied for sediments analysis. By analyzing the composition of the sediments and correlating their sources, we are able to delineate both vertical and lateral distribution of various litho-facies in the basin. Meanwhile, previous and newly dating data are all adapted as stratigraphic constraints to establish the time frame of this study.
The Taipei Basin is filled with Quaternary alluvio-lacustrine sediments, especially by the Tahan River, the Hsintien Strean, the keeling River and the little rivers near the Tatun volcanoes and the Linkou Tableland. The sediment sources of the Taipei Basin can be divided into 4 regions: the Western Foothills, the Tatun volcanic area, the Liukou Tableland and the Hsuehshan Range; each part has its unique deposit characteristic.
The result of this study shows that the sediments deposited in the northeast Taipei Basin are mainly quartz sand whilein the Hsintien Stream watershed are mostly argillite regolith and metasandstone regolith.

並列關鍵字

Quaternary ； Basin ； Borehole ； Sediments

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