螢光定年法於台灣第四紀沈積物之定年研究：以台灣西部活動構造為例

Luminescence Dating on Quaternary Sediments: Cases of Active Structures in Western Taiwan

陳雅雯(Ya-Wen Chen)

指導教授 ： 陳于高教授

國立臺灣大學/理學院/地質科學研究所/博士(2008年)

https://doi.org/10.6342/NTU.2008.03088

摘要

近十數萬年只是地球歷史短暫而微不足道的ㄧ小段，但在人類的演化過程卻是輝煌且重要的ㄧ頁。倘若科學家期望可以預測未來，掌握過去的趨勢是ㄧ個重要的關鍵，因而亟需可靠的年代資料加以佐證。本研究將就近年來螢光定年法之應用結果與適用性進行深入的探討;經過反覆測試後證實，螢光定年法可提供確實的年代資料用以進行區域構造之詮釋；當沉積層序與年代架構(特別是螢光定年所提供的連續性年代)相互配合，更可協助我們了解某些鑽井位置下的調節空間，在西南海岸平原區所呈現的地質構造意義。本研究推斷，位於研究區域西南方的沈降中心，自晚更新世後仍舊持續提供空間來接受大量的沉積物堆積；而位於東北方沿著基底面滑移的構造抬升活動，在約十萬年前就已經開始向西推移了。這些重要的地質研究結果，在填補上年代資料後，便可由原本靜態的地質現象轉變為對地質活動的探討。此外，近年來為減低因地質構造活動對人類造成的生命財產損失，所有可應用之定年方法－特別是螢光定年法，均投入活動斷層之研究，期望能對已知之地質構造提供更詳細的研究與資訊。本研究將螢光定年法分別應用在車籠埔與九芎坑斷層上，期許所得之長期滑移速率與斷層型態，可提供斷層活動性與再發周期之必要訊息。最後，基於適當的實驗測試條件，並針對不同環境進行些微的調整後，我們確信螢光定年法已能夠成功的應用於台灣西部之第四紀研究中。

關鍵字

螢光定年法 ； 第四紀 ； 台灣西部 ； 活動構造

並列摘要

A hundred thousand years is but a short period in the earth’s history; however, it is the most momentous period for human beings. If scientists would like to predict the future, learning the trend of the past is the key and reliable chronological data are needed. In this study, the feasibility and applicability of luminescence methods are presented. As results from multiple tests of such methods have so far been successful in interpreting regional tectonics, confidence is what we have. Sequence stratigraphy and continuous chronological framework, especially from the luminescence dating, are integrated to investigate the accommodation space for specific drill sites in the southwestern coastal plain of Taiwan. It is concluded that tectonic subsidence has been operating since very late Pleistocene with a depo-centre located further southwestwards. Also a tectonic uplift due to detachment westward migration has been proposed to have occurred after 100 ka. Furthermore, in order to diminish losses in an earthquake, multiple dating methods, in particular focusing on the luminescence dating method, are employed in the studies to explore the details of active faults. The Chiuchiungkeng Fault and Chelungpu Fault have both been tested in this study to deduce the long-term slip rate and fault behavior. With evidence from successful applications employing appropriate experimental testing criteria, with minor adjustments for different areas, we conclude that the luminescence dating method has passed the acceptance criteria for Quaternary research in western Taiwan.

並列關鍵字

Luminescence Dating ； Quaternary ； Western Taiwan ； Active Structures

參考文獻

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