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在青藏高原东北缘至鄂尔多斯地块沿玛沁—兰州—靖边剖面进行62个测点的大地电磁观测,采用Robust技术对观测数据进行了处理和张量阻抗分解.分析了视电阻率和阻抗相位曲线、二维偏离度、区域走向.采用RRI二维反演技术进行了资料的反演解释,二维剖面的电性结构显示:(1)玛沁断裂带、兰州深断裂带、马家滩—大水坑断裂带将剖面分为4个电性区块:巴颜喀拉地块、秦祁地块、边界带和鄂尔多斯地块.(2)区块1、2和4的地壳电性结构有类似特点:上地壳为高阻层,下地壳上部为低阻带,下地壳下部到上地幔电阻率随深度逐渐升高.区块3电性成层性差、结构复杂,是现今构造活动较强烈的地区.(3)玛沁断裂带、海原断裂带和罗山—云雾山断裂带为较陡立的超壳断裂带;西秦岭北缘断裂带为壳内断裂带.
In the northeastern margin of the Qinghai-Tibet Plateau to the Ordos block along the Maqin - Lanzhou - Jingbian section of the 62 measured points of the earth electromagnetic observation, the use of Robust technology to observe the data were processed and tensor impedance decomposition.Viewed the apparent resistivity and impedance Phase curve, two-dimensional deviation and regional trend. The inversion of data was carried out by using RRI two-dimensional inversion technique. The electrical structure of two-dimensional section shows: (1) Maqin fault zone, Lanzhou deep fault zone, Majia The beach-Dashuikeng fault zone divides the section into four electrical blocks: the Bayan Kara block, the Qinqi block, the boundary zone and the Ordos block. (2) The crustal power of blocks 1, 2 and 4 The structural features are similar: the upper crust is a high resistivity layer, the lower crust is a low resistivity zone, and the resistivity of the lower crust to the upper mantle is gradually increased with depth. (3) Maqin fault zone, Haiyuan fault zone and Luoshan-Yunwu Mountain fault zone are the steeper superhuman fault zones, and the northern margin of the West Qinling fault zone is intra-crust fault zone.