Integrated Geophysical Logging Study Of Scientific Drilling In The Yudu-ganxian Ore Concentration Area

With the continuous improvement of China’s industrialization process, thehuman society needs more and more metal mineral resources. But exploitable reserveof the present mine decrease year by year. It makes the current contradiction betweensupply and demand more prominent. Metallogenic theory and prospecting practiceshow that there is great ore potential in deep subsurface. So deep mineral explorationhas become one of the best ways to relieve the recession of resource at home andabroad. Nanling region is the important nonferrous metallic, rare metallic base in ourcountry. It has an important significance to research on the region. In order to revealsecond prospecting place of Yudu-Ganxian ore district in the Nanling mineralizationbelt, two scientific drilling deep hole, including NLSD-1and NLSD-2, have beenimplemented in the Yinkeng mine and Pangushan tungsten deposit. The continuouscoring and logging data of the two borehole have been acquired.In this paper, we mainly focus on the research of NLSD-1and NLSD-2. The logresponse characteristic of different lithology and polymetallic mineralization belts issummarized by using core and well log data. Logging curve having the sensitivities tolithology is identified by crossplot technique. Typical geological structure is analyzedand identified by using logging data. Fractures are picked making use of ultrasonicimaging logging data. Occurrence of fractures and the fracture decelopmentcharacteristics of main mineralized belts are statistically analyzed. Imaging logging’sfunction in metal ore exploration is discussed.Research shows that, in the two holes, the natural gamma ray, acoustic velocityand density logs have obvious response to lithology. The main lithology can beefficiently identified by drawing crossplot of logging lithology parameters. Thepolymetallic mineralization belts were drilled and show the combination features ofhigh polarization, low resistivity, the vertical component(ΔZ) and the horizontalcomponent (ΔH’) of magnetic anomaly in the logging figures. Typical geological structure of two holes are identified by using logging information. The position ofFault F1is deduced to be about1375m of hole NLSD-1, and the depth of granite massrock top interface is located approximately at1288m of hole NLSD-2. Dominantdistribution of two holes fracture has been obtained by researching ultrasonic imaginglogging. The results show that, in the hole NLSD-1, the high-angle oblique crossingfractures and vertical fracturess are most developed, while in the hole NLSD-2, onlythe high-angle oblique crossing fractures are most developed. The main mineralizedbelts were developed fractures.Fractures and fracture zones can be identified byimaging logging, which indicated that imaging logging results can illustrate thepossible loaction of mineralized belts. Practice has proved that the combination ofconventional logging and ultrasonic imaging logging play an important role ingeological structure of ore-concentrated area analysis and deep prospecting areas.