青藏高原东北部地区地壳电性结构特征

The electrical structure of northeastern Qinghai-Tibet plateau

通过对青藏高原东北部地区的大地电磁测深数据进行分析、处理,用非线性共轭梯度算法(NLCG)进行二维TE、TM模式联合反演,得到研究地区的地壳电性结构特征.结果表明在研究区的中下地壳内普遍存在高导层,其成因一般为部分熔融,其中在羌塘中部地壳内的局部高导异常主要受流体的影响.

The electrical conductivity model of the crust of northeastern Qinghai-Tibet is obtained from inverting TE and TM mode responses simultaneously using non-linear conjugate gradient (NLCG) algorithm. The result shows that there exist high electrical conductivity layers in the middle and lower crust in northeastern Qinghai-Tibet Plateau. Their formation mechanism is generally partially melting. And the local anomaly of high electrical conductivity in the middle Qiangtang terrane is related to the effect of fluids.