摘要
关于中国大陆岩石圈导电性结构研究越来越引起人们的重视,而目前研究大陆岩石圈导电性结构的主要方法是大地电磁测深(Magnetotelluric sounding).为此,在国家项目"深部探测技术与实验研究(SinoProbe)"专项里开展了"大陆电磁参数标准网实验(SinoProbe-01)"研究,完成了华北1°×1°地理坐标网度的大地电磁测深"标准点"阵列(Array)观测.本文详细论述了华北SinoProbe-01项目1°×1°MT"标准点"阵列观测实验的概况,以及通过精细的MT数据处理和一维Niblett-Bostick变换快速成像,所获取的华北地区岩石圈导电性三维成像模型.在分析华北岩石圈导电性结构特征的基础上,从电性结构角度把华北与邻区岩石圈划分为胶辽、燕山、鲁西、太行—吕梁等低导电性(高电阻率)块体,内蒙古、阿拉善和祁连中等导电性块体和黄淮、鄂尔多斯、秦岭良导电性(低电阻率)块体,进一步从导电性的角度证实了华北克拉通是由多个块体集合而成的观点.
The electrical resistivity structure beneath the continent of the Chinese Mainland has triggered worldwide concerns during recent several decades.The main geophysical method ofsurveying electrical structure of continental lithosphere is Magnetotelluric sounding(MT).Therefore,in the project SinoProbe-01(i.e.,Experimental Study of the Continental Standard Grid of Electromagnetic Parameters)belonging to the national research program SinoProbe(Deep Exploration Tecnology and Experimental Research of China),we have deployed 1°(Latitude)×1°(Longitude)standard MT array covering the entire North China.In this paper,we introduce the general situation of SinoProbe-01.In addition,we achieved the electrical resistivity structure of lithosphere beneath North China through fine data processing and rapid imaging by 1-D NiblettBostick transform.Based on the analysis of the lithospheric resistivity structure,the lithosphere beneath North China and its adjacent regions can be divided into several high-resistivity blocks(e.g.,Jiaoliao,Yanshan,Luxi and Taihang-Lüliang),mid-conductivity blocks(e.g.,Inner Mongolia,Alxa and Qilian)and low-resistivity blocks(e.g.,Huanghuai,Ordos,Qinling).This observation further confirm the previous inference that the North China craton was formed though amalgamation of multiple micro-continental blocks.