English  |  正體中文  |  简体中文  |  Items with full text/Total items : 67621/67621 (100%)
Visitors : 23030053      Online Users : 277
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version


    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/27569


    Title: The identified origin of a linear slope near Chi-Chi earthquake rupture combining 2D, 3D resistivity image profiling and geological data
    Authors: Lee,CC;Tsai,LLY;Yang,CH;Wen,KL;Wang,ZB;Hsieh,ZH;Liu,HC
    Contributors: 地球物理研究所
    Keywords: CHELUNGPU FAULT ZONE;CENTRAL TAIWAN;FENGYUAN
    Date: 2009
    Issue Date: 2010-06-29 18:41:05 (UTC+8)
    Publisher: 中央大學
    Abstract: A slope on the west border of the foothill near 921 surface rupture (caused by the 1999 Chi-Chi earthquake) in central Taiwan shows distinctive topographic expression that was prone to be considered as a fault scarp formed by a preexisting active fault. The 2D and 3D resistivity images clearly delineate rock surfaces which show steep, deep, gentle, and subvertical displacement beneath the slope, the toe of slope, the non-lateritic terrace, and 92 1 surface rupture, respectively, which can be attributed to the significant contrast of resistivity between gravel and rock. The horizontal sand bed and clast-supported gravel were deposited in a fluvial environment, whereas wedge-shaped gravel and colluvium were scarp-induced colluvial deposits in the trench profile. The layers shown in the depth of excavation, except for rock, has no offset or disturbance by fault ever since at least 2,480 50 year B.P., based on carbon 14 dating of charcoal sample at the bottom of trench profile. According to information from two boreholes close to the slope, an over 20-m-thick marker bed with transported shell fragments, was found for correlation. This correlation further implies the slope was not formed by fault. On the other hand, two boreholes which are far from the slope and located on the flat non-lateritic terrace frequently show fractured and sheared features. By comparison, the locations around these two boreholes indicate a reverse fault or faults that occurred before the deposition of gravel. Later on, the paleostream was developed along the foot of fault scarp that was subjected to erosion and led to subsequent retrogression or retreat of the slope. Consequently, the incision of paleostream is believed to be responsible for the high relief of rock surface around the slope. Furthermore, from resistivity and borehole data, the rock surface underlying terrace is gentle where no faults occur after the deposition of gravel. The result of RIP crossing the 921 surface rupture displays about 10 m difference in elevation of rock surface on both sides, which is greater than that of 3-4 m caused by Chi-Chi earthquake. This indicates that the 921 surface rupture is a preexisting thrust fault that resulted from several thrusting events since terrace gravel was deposited. So it is not necessary to establish an extra restricted zone for construction in study area, except close to the 921 surface rupture.
    Relation: ENVIRONMENTAL GEOLOGY
    Appears in Collections:[地球物理研究所] 期刊論文

    Files in This Item:

    File Description SizeFormat
    index.html0KbHTML368View/Open


    All items in NCUIR are protected by copyright, with all rights reserved.

    社群 sharing

    ::: Copyright National Central University. | 國立中央大學圖書館版權所有 | 收藏本站 | 設為首頁 | 最佳瀏覽畫面: 1024*768 | 建站日期:8-24-2009 :::
    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback  - 隱私權政策聲明