台灣車籠埔鑽井研究－岩芯描述、岩芯處理和分析

Abstract

研究斷層帶上圍岩和與斷層相關岩石的種類、 分布、性質和成因，以及流體的影響，對於解開地 震斷層發震帶的地質材料特性和力學行為、斷層帶 上岩石的成因，以及引發地震可能機制有相當大的 助益。台灣位於年輕的造山帶上，活動斷層遍布全 島，百年來由活動地震斷層所引發的大地震，造成 的人員傷亡和財產損失，都讓人怵目驚心，尤其 1999 年集集大地震的發生，更令人記憶猶新。但過 去台灣對於斷層帶上圍岩和與斷層相關岩石的研 究，則相當的缺少。1999 年車籠埔斷層發生劇烈的 逆衝活動，提供了學界從地表露頭至鑽取深井岩 芯，研究斷層帶和引發地震可能機制等相關問題的絕佳機會。台灣車龍埔斷層深鑽計畫從2004 年初開鑽，至 2004 年底完成A 井2000 公尺的岩芯取樣，又從 2005 年2 月中開始B 井的鑽探。A 井的岩芯描述 顯示，車籠埔斷層帶位於深度1111 公尺左右，深 度1701 公處為三義斷層，出露地層有卓蘭層、錦水頁岩和桂竹林層等。

Knowledge of the distribution, deformation and genesis of fault-related rocks and fluids within the fault zone are important to understand the characteristics of geological materials and earthquake origin in seismogenetic zone. Taiwan is located in the orogenic belt, which the active faults are widely distributed in this island. Damaged earthquakes, i.e. 1999 Chichi earthquake, occurred frequently in past hundreds years and caused vest amounts people death and properties lost. However, the researches were scarce in Taiwan for those topics. The Chelungpu thrust fault moved in 1999 provides a good opportunity to study the characteristics and origins of fault-related rocks and seismogenetic zones from the surface outcrops to subsurface drilling cores. 國立臺灣大學地質學系 The 2000 m deep Hole-A coring has been finished in the end of 2004, and then the Hole-B begins drilling in the February of 2005. Three Formations have been drilled through. They are the Cholen, Chinshui and Kueichulin Formations. Meanwhile the Chelungpu and Sanyi fault have been found in the depth of 1111 m and 1710 m, respectively.