Multi-information Metallogenic Prediction Of Skarn-type Fe-Cu Polymetallic Deposit In The Middle Segment Of Nanjing-Zhenjiang Mesozoic Magmatic Belt

The middle segment of Nanjing-Zhengjiang copper polymetallic deposit is in the east part of Middle_Lower Yangtze metallogenic belt. Some conclusions have been acquired by researching on geological, remote sensing, geophysical and geochemical.1. Based on genetic theory of contact metasomatic deposits, the results suggest that contact metasomatic type is the the main metallogenic type by study on distribution characteristics of ore body, texture and structure of ores, and mineral paragenesis sequence. Meanwhile, there are veinlet disseminated type and hydrothermal vein type.2. Combined with the geochemical characteristics in REE, stable isotope and ore-forming elements of metallogenic system, it is considered that the sources of ore-forming materials mainly are from Yanshanian intermediate-acid magma. Qixia carbonate formation is the secondary metallogenic factor. Furthermore, the structures which are nearly EW and NS trending provide advantageous space for the migration, concentration and location of metallogenic fluid.3. The ore-forming process divides into skarn-stage and hydrothermal-stage. The metallogenic condition includes magma, strata, structure and physical chemistry. According to genetic types, controlling factors, ore-forming conditions and ore-forming process of copper polymetallic deposit, the metallogenic regularity has been summarized, and the metallogenic model has been set up by it.4. Based on the guiding ideology of multi-information metallogenic prediction theory, it is considered that the more overlapped anomaly information on using the logical-information method to extract, the more complex geological structures are there, and are beneficial for bearing orebody. Compared with the favorable degree of geological metallogenetic conditions, intensity and sale of geophysical-geochemical anomalies, development degree of circular structure, intensity and sale of RS-interpretation alteration, the favorable position of mineralization, the prospecting model of location prediction has been built. After comprehensively determining the favorable position for ore-forming and combining with the prospecting model, five prospecting targets in the contact zones has been delineated, which are in the north of Funiushan, Baohuashan, the south of Tongshan and Dongmaoshan. Drilling verifying showed that there is skarn-type copper polymetallic mineralization in the contact zones in the north of Funiushan. It is proved that multi-information metallogenic prediction is an available method for exploration in the middle segment of Nanjing-Zhengjiang.