本研究利用直流電阻法針對車籠埔斷層北段豐原至南投，進行二維的電阻率影像剖面探測，了解斷層地表下電阻率分布，並推求斷層在地表下的地層分布及構造形貌，得到下列結論： (1)豐原及太平測區斷層帶兩側地層電阻率均在30Ω-m以下，其上下磐之地層為錦水頁岩或卓蘭層。與佛音寺鑽井結果相符。其斷層視傾角為60-80度向東。 (2)吉峰以南測區，上磐的電阻率低，約為1-50Ω-m，為錦水頁岩或卓蘭層；下磐的電阻率高，約為50-2000Ω-m，為頭嵙山層。是典型車籠埔斷層兩側的地層。 (3)千秋測區剖面，上磐地層電阻率均在5-30Ω-m之間，為錦水頁岩或卓蘭層；下磐電阻率約為100-300Ω-m，為頭嵙山層。與千秋國小的井柱資料相符。 (4)畚箕湖測區的E-E’、F-F’與G-G’，斷層視傾角皆約45度。依地層電阻率研判，上磐屬於細顆粒的砂質岩層，研判為錦水頁岩；下磐為大顆粒的礫石層，研判為頭嵙山層。與槽溝開挖結果一致。 (5)吉峰測區兩剖面，斷層面傾角約60度向東，上磐電阻率3-30Ω-m，研判為錦水頁岩或卓蘭層；下磐電阻率100-300Ω-m，研判為頭嵙山層。 (6)光復國中兩剖面，斷層面傾角皆為80度向東，上磐電阻率皆為6-20Ω-m，研判為錦水頁岩或卓蘭層；下磐電阻率100-2000Ω-m，研判為頭嵙山層。 A geoelectric study of the northern segment of the Chelungpu fault Yeng-Ping Wang Abstract The resistivity image profiling is used to investigate the features of the electric resistivity structures of northern segment of the Chelungpu fault, from Feng-Yuan to Nanton. Several conclusions can be drawn as follows： (1)In Feng-Yuan and Tai-Ping , the resistivity of both side the fault zone is less then 30Ω．m. Both the foot wall and hanging wall are Chinshui Shale or cholan formation. The result is fitting with the Feng-Yuan well. The fault dips eastward at an angle of about 60-80 degrees. (2)In the southern of Ji-Feng, the resistivity of hanging wall is 1-50Ω．m, and the resistivity of foot wall is 50-2000Ω．m. It indicates that hanging wall is Chinshui Shale or cholan formation and foot wall is toukeshan formation. (3)In Nanton, the resistivity of hanging wall is 5-30Ω．m, and the resistivity of foot wall is 100-300Ω．m. It indicates that hanging wall is Chinshui Shale or cholan formation and foot wall is toukeshan formation. The result is fitting with the Nanton well. (4)In profile E-E’, F-F’ and G-G’ of Ben-Ji-Hu, the fault dips southward at an angle of about 45 degrees. By the electric resistivity structure, that hanging wall is Chinshui Shale or cholan formation and foot wall is toukeshan formation. (5)In Ji-Feng, the resistivity of hanging wall is 3-30Ω．m, and the the resistivity of foot wall is 100-300Ω．m. It indicates that hanging wall is Chinshui Shale or cholan formation and foot wall is toukeshan formation. The fault dips eastward at an angle of about 60 degrees. (6)In Quang-Fu junior high school, the resistivity of hanging wall is 6-20Ω．m, and the resistivity of foot wall is 100-2000 Ω．m. It indicates that hanging wall is Chinshui Shale or cholan formation and foot wall is toukeshan formation. The fault dips eastward at an angle of about 80 degrees.
