陕西及其邻近地区地磁短周期异常和上地幔高导层的初步研究

近年来,随着对地震孕育背景和上地幔地球物理特性的研究,人们日益注意用地磁短周期异常来研究地壳和上地幔的电性结构。在我国继陈伯舫提出渤海地区西部地磁短周期异常并推测其下存在电导率异常后,徐文耀等人分析了甘肃东部的地磁短周期异常,也提出该区存在一东西向高导带。最近,祁贵仲等人利用渤海地区25个台站的地磁资料,进一

THE PRELIMINARY STUDY OF THE SHORT-PERIOD GEOMAGNETIC VARIATIONS AND A BELT OF HIGH ELECTRICAL CONDUCTIVITY IN THE UPPER MANTLE IN AND AROUND SHANXI

In this paper,the short-period geomagnetic events in and around Sha-nxi are analysed.It is found that the directions of variation in vertical component on the south and north sides of the Wei River which is taken as a rough boundary are opposite.It can be inferred that there exists an east-west belt of high electrical conductivity beneath this region.From other characteristics of short-period geomagnetic variations,a rough est-imate of shape and properties of the belt is made.Connecting this belt wi-th that discovered in eastern Kansu,a belt of high electrical conductivity of 1,000-odd km.will be formed.