Study On The Lithospheric Conductivity Structure Of Huanghuaihai Block Of North China And Statistical Method Of The "Stand Value" Of Resistivity

HuangHuaiHai block lies on the Basin of flame,northeast of North China.HuangHuaiHai block is west to the east of Taihang Mountain fracture and Shanxi fracture,north to north frcture of Bohai Basin,east to Huang River,south to Jiyuan-Huangkou fracture,Liaolan fracture and North Basin.The Bohai Basin can be invided into different depressions and uplift tectonic units,and the strike-slip faults in the northeast of the basin control the development of the whole basin.This text is based on five magnetotelluric profiles of'sinoprobe' in the Huang-Huai-Hai block.Measured 207 points within the area to conduct a comprehensive and detailed data processing,and each section is separated inversion,got over the north China block the two-dimensional electrical structure model of underground medium.Based on two-dimensional electrical structure model obtained by inversion study we found that over the plot corresponds to the lithosphere is generally low resistivity values,crustal average resistivity for decades ?m,and they are good conductors.And according to rtificial seismic exploration,there is obvious crustal gradient belt of resistivity changes with depth at the moho depth.Through the gathering area of geological,geochemical and geophysical data analysis,more accurate understanding of the lithosphere over the north China block electrical structure characteristics and dynamic mechanism is expected to be known.But the discussion about the lithospheric thinning of the north China dynamic origin,now is not exact.Because during the late Mesozoic in stretch tectonic setting.the eastern north China has the support of a large number of data,such as the extension of extensive development basins and metamorphic core complex,etc.We can speculate whether it is a stretch that led to the craton destruction.As the relationship between magmatism and lithospheric thinning,whether mechanical tension caused the lithospheric thinning,or due to lithospheric thinning of the earth's crust shallow drawing,is unclearly yet.At the same time,this paper also puts forward a statistical method based on the results of 2-d resistivity inversion:exponential weighted moving average method.Based on the constructed model forward response of 2-d inversion results and the measured data of 2-d inversion results,we get a conclusion.Although this method can't eliminate phenomenon of abnormal low value caused by surface conductive shielding layer underground high resistance,but for the inversion of some false anomalies could have an adverse effect.But at present this method is only confined to the statistics below the center of the resistivity one-dimensional results,and practical remains is expected to be strengthened.