【摘要】 为研究安徽省繁昌地区岩体分布及地层间的接触关系,确定可能的矿体赋存空间,开展了可控源电磁探测。剖面长度15 km,观测数据为来自两个发射源的电场振幅。采用有限内存拟牛顿法进行三维反演,反演过程中,正演模拟采用考虑场源分布特征的交错网格有限差分技术。观测数据三维反演模型显示,剖面中段、最南端与最北端呈高阻特征;靠近中段的两侧呈低阻特征;整个剖面电阻率呈高-低阻相间的变化特征。结合地质资料,三维反演的电阻率变化反映了研究区地表白垩系、晚泥盆统、早志留统地层以及深部奥陶系地层广泛发育的特征。结果说明多源单剖面的可控源电场振幅|E_x|数据进行三维带源反演的可行性与必要性。更多还原

【Abstract】 In order to study the rock mass distribution and the contact relationship between strata in Fanchang area of Anhui Province,and to determine the possible occurrence space of ore bodies,controllable source electromagnetic detection was carried out. The length of the profile is 15 km,and the observed data are the electric field amplitudes from two emitters. In this paper,the finite memory quasi Newton method is used for 3 D inversion. In the inversion process,the staggered grid finite-difference technique taking into account the distribution characteristics of field sources is used in forward modeling. The three-dimensional inversion model of observation data shows that the middle,southernmost and northernmost sections of the profile are characterized by high resistivity,while the two sides near the middle section are characterized by low resistivity. Moreover,the resistivity of the whole profile is characterized by the alternation of high and low resistances. Combined with the geological data,the resistivity change of 3 D inversion reflects the widespread occurrence of Cretaceous,Late Devonian,Early Silurian and deep Ordovician strata in the study area. The results of this paper show the feasibility and necessity of 3 D band source inversion with controllable source electric field amplitude |E_x| data of multi-source and single profile.更多还原