地气测量在北祁连盆地区找矿突破及其意义

北祁连地区是我国最重要的块状硫化物床成矿省之一,虽然该区分布有我国最大的块状硫化物矿床——白银矿田,以及200多处中小型矿床及矿(化)点,但除白银矿田外,多年来在找大矿方面未能突破。原因在于缺乏必要的手段,找矿勘探工作仅限于盆地周边的出露区。近几年,地气测量在黑河盆地的红层覆盖区先后发现了赖都滩和白柳沟矿体,不仅说明地气测量方法有效,而且说明黑河盆地具有寻找大型白银式多金属矿床的潜力。建议采用地气法对整个盆地进行系统勘查,并结合其它方法,优选出最佳的找矿靶区。作者认为,本区找矿突破可为整个北祁连地区其他盆地寻找块状硫化物矿床指出新的找矿方向,将找矿重点转到盆地区,以实现我国块状硫化物矿床勘查的全面突破。

BREAKTHROUGH IN MINERAL EXPLORATION USING GEOGAS SURVEY IN THE BASIN AREA OF NORTHERN QILIAN REGION AND ITS SIGNIFICANCE

Northern Qilian region, in which more than two hundred ore deposits or spots, including Baiyin, have been discovered, is an important VMS mineralization province in China. Except for Baiyin, however, no remarkable breakthrough has been made in exploration of large deposits. This is attributed to the fact that these ore deposits or spots occur in outcrop areas around the basin and no effective technique could be used to explore the covered area. After the geogas survey was adopted in ore exploration in Heihe basin in 1998, Laidoutan and Bailiugou orebodies were found under thick overburden. These results indicate that geogas survey, as a useful means for VMS deposit exploration, can play an important role in mineral exploration in the covered basin, and that Heihe basin is likely to have potential in finding a superlarge Baiyin-type VMS deposit. The authors suggest that further geogas survey should cover the whole basin to delineate the prospect areas in combination with other techniques such as geophysical exploration and soil mercury survey. It is hoped that the discovery of VMS deposits in Heihe basin will lead to a series of considerable breakthroughs in looking for VMS deposits in other basins such as Subei, Menyuan and Tianzhu in Northern Qilian region.