关键词: 地学断面, 大地电磁测深, 高导层, 电性结构, 江苏, 内蒙

Abstract: The features of deep conductivity structure along Xiangshui-Mandal Geoscience Transect are described in this paper basing on newly obtained magnetotelluric data. Large resistivity contrasts can be found on both borders of North China platform. The depth of the crustal high conductivity layer changes abruptly from 21km to 34km beneath Nei Mongol fold system on the northwestern end of the transect. While it is absent beneath Subei-Jiaonan terrane on the southeastern end of the transect,where two high conductivity layers are detected in the upper mantle. The crustal high conductivity layer is well developed in the Cenozoic basins within North China Platform with a relatively shallow depth. The depth of the upper mantle high conductivity layer along the transect ranges from 60 to 127kin,with a general tendancy of decreasing in depth from northwest to southeast,forming local uplifts beneath Ho-Bao basin,Central Hebei depression and Tan-Lu fault zone. It reflects the characteristics of the regional geology and the deep tectonic movements.

Key words: Geoscience Transect, Magnetotelluric measurements, High conductivity layer, Conductivity structure, Jiangsu, Nei Mongol