Dabie Orogenic Belt, Mesozoic Magmatism And Mineralization Geochemical Study

Advicers:Prof.Yue Shucang ,Acadimician Chang Yinfo Dabie Orogenic belt is,which is between Northern China a Block and Yangtze Block,a collisional orogenic belt that had been finally converged togather. Dabie orogenic belt has become a 1~otspot 揳rea to study the Ultra-high-pressure(UHP) in the world now. With UHP been discovered, which is marked by ecolgite with bearing-coesite and bearing-rn icrodiamond. The updating focus of studing orogenic belt on its formation,the geodynamic backgroubd of UHP belt and its uplifting mechanism, no more attention relationship mineralization and orogeny in the orogenic belt. The major contents in this thesis are the common issues about the mineralization of the orogenic belt as below:( I )The regional geological background of the mineralization since Mesozoic in dabie orogenic belt and around it by using the historical tectonic analysis.(2)Basing on analysising of igneous rocks tectonic assemblage . series.. inside orogenic belt and near it,crust-mantle interaction of orogenic belt is studied in detail by means of 搇ithoprobe 憕(3)The characteristics of regional petrogenesising-mineralogenesising material source條iquid .Dre-forming System in orogenic belt are studied with trace isotope ..Laser Raman microprobe and geochemistry imitating of trace elements.(4)Discussing about the relation of couple between orogeny and diagenesis mineral ization in time and space with new geodynamics and studying of the magmatic rocks and the geochemistry of diagenesis and mineralization of endo- metal deposits.(5)By means of regional mineralization analysis and combined with some progresses in regional minerogenesis, characteristics of ore-forming in orogenic belt are discussed in detail. Through the systematic studying about the magmatism and minerogenesis geochemistry of orogenic belt in Mesozoic, Some advance achievement are got as below: (I) It is proved that lndosinian movement and Yanshanian movement are two independent but mutual orogenic events. This is first to studying on the mineralization system of complex collisional continental orogenic belt and is supposed that the research method, which take the material source-magma-fluid-mineralization system as a guide and regional mineralogenesis system. It will promote advancement in regional minerogenesis. (2) In Dabie orogenic belt, Mesozoic volcano-intrusive rocks can be divided into four series ,that is high-potasium calc-alkaline series~ shoshonite series~ alkaline series. tholeiite series; they formed different times and tectonic settings that can be confirmed on the uplifting type(post-orogeny)(J,- J3).. syno-orogeny type(J3-K1) and extension type(dome type)(K1).Sometimes the volcano-intrusive rocks formed coupling relationship of times and space of orogeny and geodynamic environments- are discussed in full and clear. (3) Based on multiple geochemistry constrain, trace elements imitating, that are studied on material system of petrogenesising and minerogenesising in different tectonic units. It is proved that material source of petrogenesising and minerogenesising are mainly from 慪angtze type basement?and it was different source between Northern Dabie and southern Dabie in Mesozoic. The reason that ore-forming scale is different between northern Dabie and southern Dabie is originated different 3 material source. (4) First to pose and expound characteristics of fluid system in Dabie orogenic belt at home, the...