老挝玻里坎塞省塔帕巴钾盐矿区地质特征及成矿远景评价

Geological Feature and Metallogenic Prospect Evaluation of Tapaba Potash Mining Area in Bolikhamxay Province,Laos

老挝万象平原是世界上重要的钾盐矿分布区,老挝玻里坎塞省塔帕巴县钾盐矿区位于万象平原东部地区,矿区南邻地区已经发现具有工业意义的钾盐矿,说明塔帕巴县钾盐矿区具有较好的钾盐找矿地质条件。在万象平原钾盐矿勘查成果的基础上,通过在塔帕巴地区开展1∶5万地质调查及物探测量(重力调查及大地电磁测深)工作,识别出4个局部重力异常带。重力异常反映了盐岩体顶界面的构造起伏和厚度变化。重力低反映盐岩体厚度膨大;重力高反映盐岩体厚度变小。G2、G4重力负异常带反映出盐岩体上隆、厚度变大的特征,显示出较好的找矿前景,根据对全区资料综合分析、研究,全区共划分Ⅰ类远景区1个,Ⅱ类远景区1个,为今后找矿指明了方向。

The Vientiane Plain in Laos is an important distribution area of potash mines in the world.The potash mine area in Tapaba County,Bolikhamxay Province is located in the eastern part of Vientiane Plain.Potash mines of industrial significance have been discovered in the southern part of this mining area,which shows Tapaba potash mining area has good geological conditions for potash prospecting.Based on exploration results of potash mines in Vientiane Plain,four local gravity anomalous zone were identified by carrying out the 1∶50000 geological survey and geophysical measurement(gravity survey and magnetotelluric sounding)in Tapaba area.The gravity anomaly reflects the tectonic fluctuation and thickness change of the top interface of salt rock body.Low gravity indicates that the thickness of salt rock body expands;high gravity means that the thickness of salt rock body decreases.The G2 and G4 negative gravity anomalous zones reflect the characteristics of uplift and thickening of salt rock body,showing good prospecting potential.According to comprehensive analysis and study of the data,the whole area is subdivided into one prospective area in ClassⅠand the other prospective area in ClassⅡ,which shows the direction for future prospecting.