Study On Inner Mongolia Maoxigadaban Pb-Zn Polymetallic Deposit Mineralization Characteristics And Prospecting Direction

The Maoxigadaban Pb-Zn polymetallic deposit, which is discovered recently in southern Da Hinggan Ling, dominated by Pb-Zn, associated with Ag and Cu. The Deposit belongs to the type of the mesothermal magmatic and hydrothermal filling and replacement, the ore bodies are produced in the faults.Study of metallogenic material shows that, ore body located on the volcanic framework fault and Hercynian diorite have similar REE composition and distribution pattern, it is indicates that the material may be of the same origin; ore located on wuertawula district and Yanshanian granite also have similar REE characteristic. The δ34S range of sphalerite and galena is consistent with the range of the igneous rocks, it is indicated that the sulfur in the ore is originated from the magma.Metallogenic fluid research shows, δ18O and δD on the charts in initial magmatic water at the lower left, the metallogenic fluid not only contains magmatic water, but also mixed with meteoric water. Lab results on homogenization temperature of fluid inclusions in mining district are mainly concentrated in between 260 ℃ and 350 ℃, suggests Maoxigadaban Pb-Zn polymetallic metallogenic fluid for the mesothermal hydrothermal; mineralization temperature decreased from southeast to northwest, the migration direction of metallogenic fluid may for the southeast to northwest migration, we considered that the northwest structure is the ore-passing structure; the homogenization temperature of silicification inclusions which has nothing to do with mineralization is much higher than that of the ore bearing, suggest that multiple stage hydrothermal activity, and there was no association between higher temperature of the silicification and mineralization; the homogenization temperature of fluid inclusions of chalcopyrite-pyrrhotite mineralization stage is higher than that of sphalerite-galena mineralization stage; the overall salinity of fluid inclusions is low, which may be caused by the addition of meteoric water during the metallogenic process.The metallogenic process is as follows: In Permian, hercynian diorite magma intrusion, metallogenic fluid of magmatic evolution was located in faults of andesite, forming the hercynian Pb-Zn polymetallic ore. To the Jurassic, metallogenic fluid originated Yanshanian granitic magma migrated along the north-west fault. Meteoric water mixed in metallogenic fluid, it reduces the temperature and salinity of the fluid. Metallogenic fluid deposit in the secondary NW and NE trending faults.The trend of Pb-Zn polymetallic mineralization belt is north west direction. The ore-passing structure is north-west direction, NWW and NE trending faults are host structure.Because volcanic framework fault mineralization is well, combined with the work of IP results, IP anomaly of NW faults and volcanic framework fault are considered prospecting vantage area.