초록 close

The first magnetotelluric (MT) transect across the Korean Peninsula was obtained traversing from the East Seashoreline to the Yelow Sea shoreline. The MT survey profile was designed perpendicular to the strike of the principalgeologic structure of the Korean Peninsula (N30oE), so-called China direction. MT data were achieved at 50 sites withspacings of 3~8 km along the 240 km survey line. The impedance responses are divided into four subsets reflectingtypical geological units: the Kyonggi Massif, the Okchon Belt, the western part of the Kyongsang Basin, and the easternestimated to be about 3 km to 8 km and its resistivity is a few hundred ohm-m. A highly conductive layer with aresistivity of 1 to 30 ohm-m was detected beneath the sedimentary layer. The MT data at the Okchon Belt show peculiarresponses with phase exceding 90o. This feature may be explained by an electrically anisotropic structure which iscomposed of a narrow anisotropic block and an anisotropic layer. The Kyonggi Massif and the eastern part of KyongsangBasin play a role of window to the deep geoelectrical structure because of the very high resistivity of uper crust. Thesecond layers with highest resistivities in 1-D conductivity models occupy the upper crust with thicknesses of 13 km inthe Kyonggi Masif and 18 km in the eastern Kyongsang Basin, respectively. .......... . : ...... .... ....... ..... .... .... ... .. ..... ... ...