大地电磁测深资料在思茅坳陷基底构造特征研究中的应用

通过对思茅盆地21条剖面，计1007个测点的大地电磁测深资料的分析认识，采用有效视电阻率数据对剖面进行反演处理，继而从电性特征方面对坳陷的双重基底构造进行了研究。研究成果表明：坳陷内中生界侏罗系、元古宇浅中变质岩是剖面构造层追踪和划分的标志层；基底平面特性上除中央凸起外，呈现自东西两侧向中央逐步下降的三级构造格局；古生界沉积变质基底的起伏与结晶基底间有一定的继承关系，但局部起伏范围、位置因多期的构造运动而表现较大区别。

ELECTRIC CONDUCTIVITY CHARACTERISTICS OF BASEMENT TECTONICS IN SIMAO BASIN, YUNNAN PROVINCE

Magnetotelluric(MT) data were obtained at 1007 sites along 21 profiles in the basin of Simao areas.Using data of effective apparents,the author got the inversion result of each line.The new analysis and realization of Simao Basin were based on magnetotelluric sounding.Jurassic(Pz) and metamorphic rocks(Upper Pt) characterized by lower apparents serve as indicator layers for the division of the structure layer.Except for the central uplifted area,the dual structure has the surface character of gradual descending from margin to center along the EW direction.In addition,the basement tectonics of Pz has some inheritance relation with the crystalline basement.Nevertheless,the limits and positions of local undulations show remarkable differences due to multi-stage tectonic movement.