辽东白云金矿区深部地质结构的瞬变电磁法探测

白云金矿床位于华北克拉通东北部辽东青城子矿集区，具有深部找矿潜力.为寻找白云金矿区深部及外围矿体，应用大功率瞬变电磁系统开展了白云矿区含矿地层和控矿构造的勘查.野外数据采集采用中心回线和大回线2种装置.大发射磁矩（7.2×106A·m2）和低发射基频（5 Hz）保证了高数据质量和长的有效观测时间，从而加大探测深度.研究区地层主要为大石桥组三段和盖县组.大石桥组三段总体电阻率较低，主要由透辉透闪片岩和含石墨大理岩引起.盖县组主要成分为片岩和变粒岩，属中高电阻率.研究结果表明瞬变电磁法可以有效探测大石桥组三段和盖县组的分布以及其中发育的褶皱和断裂.3条瞬变电磁测线反演结果表明，白云金矿西部受到较大挤压，形成明显的推覆构造，而白云矿床东部褶皱平缓，挤压相对较弱. 

Exploration of Deep Geological Structure of Baiyun Gold Deposit in Eastern Liaoning Province with TEM

The Baiyun gold deposit in the Liaodong Province,NE,North China craton (NCC),is a large-scale gold deposit with great potential for deep exploration. In order to find deep and peripheral ore in the Baiyun gold deposit,transient electromagnetic (TEM) method was applied to the exploration of strata and structures. Both fixed-loop and central-loop configurations were used in field data acquisition with a high-power transmitting system to ensure high data quality and long observation time. The local strata are mainly the third member of Dashiqiao Formation and Gaixian Formation. The third member of Dashiqiao Formation is of low resistivity in general,which is mainly caused by diopside diorite schist and graphite bearing marble. The main components of Gaixian Formation are schist and granulite,which are of middle to high resistivity. The results show that TEM method can detect the distribution of Gaixian Formation,Dashiqiao Formation,and the folds and faults within these formations. The inversion results of three TEM lines show that the western part of the Baiyun deposit has been greatly compressed,forming obvious nappe structure,while the eastern part of the Baiyun deposit is gentler in fold and weaker in compression. Exploration results show that TEM methods are useful geophysical tools in the study of ore bearing strata and ore control structures in Baiyun gold deposit area.