| Lannitang Porphyry copper deposit in Shangri-La County, Yunnan is located inthe southern section of the Indosinian Yidun-Zhongdian island arc, which has foundPulang, Hongshan, Xuejiping and other medium and large porphyry Cu (Mo) deposit,Lannitang Porphyry copper deposit is located in Xuejiping mineralization subzone ofZhongdian island arc copper-polymetallic mineralization belt.Regional tectonic line direction is NNW-SSE, magmatic rocks and minerals ofCu, Pb, Zn, Mo, Au and Ag are widespread, a series of NNW trending tight linearfolds and synthetic faults develop, secondary faults often tend to be ore structure.Triassic strata and late Indo acidic shallow rock are mainly exposed in the mine area.Based on systematically collected on previous studies, through detailed fieldgeological investigation and sample collection of Lannitang copper deposit,combined with indoor thin section and polished section microscope observation, rockand mineral samples analyzed data, after a comprehensive study the author made thefollowing understanding:（1）Newly acquired ore of phyllic diorite of Lannitang mine area zircon U-Pbisotopic age is225.2±3.5Ma, as Indosinian magmatism.（2）The mine s alteration is strong, such as silicification, sericitization, chloritization, carbonatization，epidotization，actinolitization and clayzation. Lannitang Porphyry copper deposit has obvious alteration and characterized by zoningas silicification'sericitization'pyritization (phyllic alteration)'meta-andesitization outwardly, the ore body is mainly distributed in phyllic alteration belt while meta-andesitization belt has no or weak mineralization.（3）Lannitang is porphyry copper deposit, the ore s wallrock is mainly phyllicdiorite. The phyllic diorite has second texture feature, was formed by containingphenocryst mineral and injection of residual magma with rich fluid components andmetallic elements. （4）Research on geochemical sectional of Lannitang copper deposit shows Cu、Mo&S have significant positive anomaly in copper mineralization site, while irongroup elements (Ti、V、Cr、Mn、Co) have obvious negative anomaly. These featuresindicate that Lannitang porphyry copper deposit possesses unusual structural featuresof hydrothermal primary halo.（5）The Lannitang copper deposit has reached medium-sized, the ore body mainly concentrated in the range of300~400m appears as lenticular or vein, the space between the veins have the right line arranged en echelon distribution. The copper grade is higher in the section of silicification or quartz stringer, quartz net vein and quartz vein body more developed; Vein quartz-sulphidemineralization superimposed is common in rich ore area, the long axis of thevein structure isconsistent with direction of the mine. Ore minerals are mainly chalcopyrite,pyrite, small amounts of bornite, covellite.（6）Intense phyllic diorite rock or hidden rock are macroscopic ore-prospectingsigns of looking for porphyry copper deposit, intersections of tectonic and abnormallocations of pedogeochemistry are important prospecting target areas. |
PDF Full Text Request