【摘要】 砂岩型铀矿是我国目前铀矿勘查中最重要的类型之一,北方中新生代盆地有寻找砂岩型铀矿的广阔前景。由于其埋深大、上覆沉积泥岩层较厚,常规物化探方法在该类型铀矿的应用效果不佳。本文在二连盆地巴音杭盖地区开展了可控源音频大地电磁测量(CSAMT)和土壤氡气测量,在重点异常地段进行了CSAMT正反演和土壤氡气抽气试验,然后对推测的砂体和土壤氡气异常部位进行钻孔揭露,结果表明砂体厚度和位置与CSAMT推测较为一致,并发现了好的铀矿化线索。该方法为该地区下一步砂岩型铀矿地质勘查提供了有效的依据,对我国北方砂岩型铀矿开展地球物理工作有一定的借鉴和指示意义。更多还原

【Abstract】 Sandstone type uranium deposits are one of the most important types encountered during uranium exploration in our country at present,which have broad prospects in the Mesozoic-Cenozoic basins in northern China. Due to their large burial depth and thick overlying sedimentary mudstone,conventional geophysical and geochemical methods are not very effectiv for prospecting these uranium deposits. To solve this problem,we attempted to use jointly the controlled source audio magnetotelluric( CSAMT) method and soil radon measurement to conduct such surveys,taking the Bayinhanggai area in the Erlian Basin,Inner Mongolia as an experimental site. At the chosen anomaly sections,forward modeling and inversion of CSAMT data and soil radon aspiration tests were carried out. Then the soil radon anomalies and inferred sand bodies were examined by drilling. The results show that thickness and positions of the sand bodies from soil radon data are in good agreement with that from CSAMT,providing a good clue of uranium mineralization. It provides an effective basis for the next step of geological exploration of sandstone type-uranium deposits in this area,and can shed light on geophysical surveys for sandstone-type uranium deposits in the north of China.更多还原