Geological Characteristics And Deep/Peripheral Prospect Of The Pengshan Sn Polymetallic Ore Field In Northern Jiangxi Province

The Pengshan Sn ore field is located in the Jiurui district,Northern Jiangxi Province,Middle and lower Yangtze River.Tectonically,it is situated in the north margin of the Jiangnan Orogenic Belt which is the junction zone between Yangtze and Cathaysian blocks.It was a newly discovered large ore field enriched in Sn,Pb and Zn deposits.Previous studies mainly focus on individual mineral deposit and systematic research on the whole ore field is relatively low.Prospecting work was mainly conducted at depth shallower than 300 m and has discovered economically important orebodies around the Pengshan granite intrusion.Recently discovered orebodies in the deep and peripheral parts are limited,where still have great potential for mineral exploration.This thesis foscues on the Pengshan ore field integratedly with different approaches in mineralogy,petrology,mineral deposit,geophysics and geochemistry.Combined the summary of previous studies and new prospecting results in the deep and peripheral parts,the geolgical characteristics are sysmatically described.Based on the summary geochemical characteristics of mineral deposit and mineralization age,ore-forming conditions are further explored and metallogenetic regularity and controlling factors of mineralization are summarized.A mineralization model is established for future mineral prospect and exploration work.This thesis obtains the following understandings.The summarized geochemical features of trace elements,REE and S-Pb isotopes indicate the ore-forming materials are sourced from the granitic magmastism.The emplacement of the Pengshan granite intrustion is the prerequisite to form Sn polymetallic mineral deposits.The Yanshanian granitic magmatism result in metal exsolution and hydrothermal activity.The cooling of ore-forming fluid result in the metal precipitation in the dome structure and its secondary structures,which forms a metal zonation from the proximal granitic intrusion to the distal wall rocks.Geological,geophysical and geochemical studies of the Jijiajian,Yangquanshan,Zhufengguijia and Kushan'ao prospective areas indicate that interlayer sliding zone,F3,F5 and F9 faults and their secondary fautls are favorable sites for ore deposition.Tin orebodies in Jijiajian and Yangquanshan are controlled by the drilling projects.The depth(?1000 m)of the hidden granitic intrusion in the Zhupengguijia is refined by the geochemical soil survey,geological mapping and controlled source audio magnetic telluric.Geochemical prospecting data reveal 5 Au,10 Ag,4 Pb,4 Zn,9 Cu,6Fe,1 Bi,2 Sn,6 As,1 Hg anormalies,which offer good references for further prospect.