综合测井在陕西商南县光石沟花岗伟晶岩型铀矿勘探开发中的应用效果

花岗伟晶岩型铀矿床是一种重要的铀矿化类型，其矿化层严格受到花岗伟晶岩脉控制，矿化层围岩为片岩、片麻岩和混合岩等。花岗伟晶岩脉由硅质物肢结，坚硬质密，不透水，其测井结果表现为高电阻和高自然伽玛特征。而其围岩片岩、片麻岩和混合岩层理和解理非常发育，并富含层间水，测井结果表现为低自然伽玛、低电阻和低自然电位异常特征。花岗伟晶岩型铀矿含矿层与其围岩物性差异较大，利用地球物理测井参数的差异来评价岩矿层和铀成矿规律显然是一种较好的铀矿勘查工作方法。FD--3019伽玛定量测井是铀矿钻探勘查定量解释必不可少的一项基本测井工作；2007年以前花岗伟晶岩型铀矿钻探勘查没有尝试用电阻率、自然电位等综合测井参数评价预测铀矿化情况，实践结果证明通过综合测井曲线解释能够更准确的预测花岗伟晶岩脉的展布规律，科学划分钻孔地质剖面，为花岗伟晶岩型铀矿勘查评价和预测提供可靠依据，并且及时准确的指导野外生产和钻探设计工作。

APPLICATION OF COMPREHENSIVE LOGGING IN EXPLORATION OF URANIUM ORE IN GRANITE PEGMATITE IN GUANGSHIGOU,SHANGNAN COUNTY, SHAANXI PROVINCE

Granite pegmatite uranium deposit is one of attributes of uranium mineralization and the granite pegmatite veins control the distribution of mineralized layers of uranium, the wallrock of which is mainly composed of schist, gneiss and migmatite. The granite pegmatite veins are hard, compact and impermeable because of cementation by siliceous materials, pro- ducing the logging results with high resistors and high nature gamma. Beddings and joints in schist, gneiss and migmatite of wallrocks are well developed and rich in interlayer water, producing the logging result with low nature gamma, low resistors and low spontaneous po- tential features. Since a great diversity of physicality occurring in between the granite peg- matite uranium and wallrocks, the diversity of parameters made by geophysical logging would be nice for assessment of drilling for uranium ore and uranium mineralization. FD- 3019 quantitative gamma logging is absolutely basic to quantitative interpretation of drilling for exploration of uranium. Practical results have indicated that application of comprehensive logging curves may enable the interpretation more accurate in prediction of the distribution of granite pegmatite veins and reasonable dipartition of drilling sections, thus providing reliable evidences for prediction and assessment of exploration of granite pegmatite uranium ore and guidance for exploration and drilling design.