青藏高原东北缘航磁异常研究

A study on aeromagnetic anomalies in the northeastern margin of the Qinghai-Tibet Plateau

根据中国及其毗邻海域航空磁力异常资料,经数字化处理,得出青藏高原东北缘的航磁异常数据.对航磁异常数据进行化极和小波多尺度分解,分析青藏高原航磁异常的空间展布,并探讨磁异常与地质构造的联系.结果显示,青藏高原东北缘的航磁异常的空间展布与该地区的地质构造基本吻合.鄂尔多斯与秦岭造山带的交界处的磁异常由东西向逐渐转为北西向,祁连造山带磁异常的北西向展布,揭示了在印度板块和欧亚板块的碰撞挤压下,青藏高原东北缘的深部物质在刚性的鄂尔多斯地块的阻挡下,物质沿着北西向的祁连造山带和东西向的秦岭造山带流动.

Based on the anomalous data of aviation magnetic anomalies in China and its adjacent seaarea, this paper obtained the aeromagnetic anomaly data of the northeastern margin of the Qinghai-Tibet Plateau.The spatial distribution of aeromagnetic anomalies in the Qinghai - Tibet Plateau was analyzed by means of polarized and wavelet multi - scale decomposition, and the relationship between magnetic anomalies and geological struc- ture was discussed. The results show that the spatial distribution of aeromagnetic anomalies in the northeastern margin of the Qinghai - Tibet Plateau are consistent with the geological structure in the area.The magnetic anom- alies at the junction of Erdos and Qinling orogenic belts are gradually shifted from east-west direction to north- west direction and northwest direction of the Qilian orogenic belt, revealing the northeastern part of the Qinghai- Tibet Plateau under the collision and squeeze of the Indian plate and the Eurasian plate.The deep material in the rigid Ordos block, the material flow in the northwest of the Qilian orogenic belt and the east-west of the Qinling orogenic belt.