云南省永胜县分水岭铜矿找矿模型初探

Prospecting Model for Fenshuiling Copper Deposit in Yongsheng County,Yunnan Province,P. R. China

矿区位于丽江台缘褶皱带东侧边缘，南北向程海断裂与北东向箐河断裂交汇部位，同属马厂箐至宁蒗斑岩成矿带，区域上斑岩体成矿元素丰度值较高，含Cu50×10-6-500×10-6、Pb50×10-6-300×10-6、Zn20×10-6-200×10-6。结合遥感影像及地球物理特征，圈出了约400km2的光茅山．分水岭斑岩铜、钼矿成矿远景区。而后以分水岭岩体及其蚀变域（角岩）分布范围为依据，将重点工作靶区面积缩减为30km2。分水岭矿区位于Cu、Mo、Pb、Zn组合地球化学异常范围内。矿区内H3异常Cu元素平均含量295×10-6、最高含量1461×10-6，Mo元素平均含量5．46×10-6、最高含量61．1×10-6，H3异常范围是本区首选最佳找矿地段，靶区面积进一步缩小到15krn2左右。在该靶区内，金属矿物分带较明显，由内向外依次为石英＋钾长石＋黄铁矿-辉钼矿＋黄铜矿＋黄铁矿-黄铜矿＋辉钼矿＋黄铁矿．黄铁矿，同时高极化率、低电阻率，为寻找硫化物的有利条件，所以金属矿物分带、激电异常结合磁异常及地表直接矿化为区内矿体直接定位的重要标志。本文就上述逐级筛选靶区的过程进行探讨，初步建立了该区找矿模型。

The studied mine is located in the eastern edge of a platform edge which is belonging to the Lijiang fold belt, in the confluence of SN Chenghai fracture and NE Qinghe fracture, belonging to the Machangqi--Ninglang porphyry metallogenic belt. Some elements are abundant in this region, which contribute a lot to the porphyry deposit. For example the element abundance of copper is from 50×10-6 to 500×10-6, and lead is from 50×lO-6 tO 300×10-6, and zinc is from 20×10-6 to 200×10-6. Based on the study on remote sensing image and geophysics date, exploration of copper ore and molybdenum ore was put forward. With the help of these data, a 400km2 mineralizing prospect of the Guangmao hall and Fenshuiling area was made. Based on the range of rock masses and hornfels in Fenshuiling rock masses, an important mineralizing prospect with 30 km2 was obtained. The Fenshuiling area is situated in a geochemical anomalies zone with copper, molybdenum, lead, and zinc. H3 anomalies are the best marks to the ore belt in this area. For this reason, we can reduce the target area of mineralizing prospect to only about 15 km2. Where the average content of the copper is 295×10-6, and at the same time, with the highest content of 1461×10-6; the average content of the molybdenum is 5.46×10-6, with the highest of 61.1 × 10-6. In the target region, the dissimilitude of metallic minerals is obvious. The mineral compositions from inside to outside are quartz ＋ potash feldspar ＋ pyrite-molybdenite ＋ chalcopyrite ＋ pyrite-chalcopyrite ＋ molybdenite ＋ pyrite-pyrite. While, for high polarizability and low resistivity are beneficial for finding sulphides, the metallic minerals zoned clearly the abnormal of induced polarization, the magnetic anomaly and the mineralization at the surface, being regarded as the most important symbol of delineate the target in this region. In this article, the authors explore clearly how to delineate the target area using above methods, and how to build a model for model for geological prospecting in this region.