松辽盆地南部局部排泄构造遥感识别与铀找矿方向探讨

Remote Sensing Identification of Local Drainage Fault Structures and Uranium Prospecting Direction in the South of Songliao Basin

局部排泄构造对砂岩铀成矿起重要控制作用,识别局部排泄构造对砂岩铀矿勘查具有积极意义。盆地内部局部排泄构造常被土壤、植被、沙漠覆盖,隐蔽性高,地表露头尺度识别难度大,而遥感技术具备宏观观测能力,为识别隐蔽构造提供了新途径。本文以松辽盆地南部的Landsat 8遥感影像为数据源,经K-T空间变换得到可以指示地表水动力活动的亮度、绿度、湿度指数。在此基础上结合基础地质资料,对松辽盆地南部的水动力环境进行了分析,对该地区局部排泄构造进行了识别。结果表明,松辽盆地南部蒸腾作用强烈,植被分布于盆地边缘与盆内开鲁-通辽-双辽一带,土壤湿度较大,但咸水环境分布广泛。在通辽附近、开鲁北西部、双辽西部识别出多条局部排泄构造,且这些构造与已知铀矿床(矿化点)具有较好的空间相关性,显示沿局部排泄构造有很好的找矿前景。

Local drainage fault structures play an important role in mineralization of sandstone type uranium deposits,and the identification of these structures is of significant importance for uranium exploration.However,these structures in a basin are often covered by soil,vegetation and desert,which are highly concealed and difficult to identify the scale of surface outcrop.The remote sensing technology has the ability of macroscopic observation,which provides a new way for the identification of hidden structures.This work selected the Landsat 8 remote sensing images in the south of Songliao Basin as data sources,and obtained the brightness,greenness and wetness index of surface hydrodynamic activity by K-T spatial transformation.On this basis,combined with the basic geological data,the hydrodynamic environment in the south of Songliao Basin was analyzed,and the local drainage fault structures in this area were identified.Results show that transpiration was strong in the south of Songliao Basin,with vegetation distributed in the margin of the basin and the Kailu-Tongliao-Shuangliao area within the basin.The soil moisture was relatively high,and saline water environment was widely distributed.Several local drainage fault structures have been identified near Tongliao,in the northwest of Kailu and west of Shuangliao,and these structures have a good spatial correlation with known uranium deposits(or mineralization points),indicating that there is a good potential of ore prospecting along the local drainage fault structures.