Study On Metallogenic Regularities Of Copper Deposit From The Mesozoic To The Cenozoic, Gangdise Metallogenic Belt

Gangdise metallogenic belt,which is located between the bangong hu-nujiangsuture zone and the Yarlung zangbo suture zone,Nearly East-west trending,up to2000km,the formation of giant ore belt controlled by evolution of tethys sea andcollision of India continental to Asian continental. There are more than hundredof found deposits,the types of Mineral resources including copper,gold,iron,lead,zinc,tungsten,molybdenum,bismuth,silver,salt and other kinds. The mainly copper deposit covers porphyry,skarn type,hydrothermal type,type of magma.Especially,the porphyry and skarn type copper are the most important.Tectonic evolution of Gangdise metallogenic belt made part of the structuralevolution of Tibet-san jiang orogenic system,the structural evolution consists of three phases: active continental margin evolution in Paleozoic,island arc-basin more-evolution in Mesozoic, India-Asia continental collisions inCainozoic. The tectonic units devote into seven tectonic unit from north to south,They in turn are isnaqu-lolong inepicontinental basin（T₃-J）,the anglonggangri-bange-tengchong magmatic arc belt（K）,the Shiquanhe-Shenzha-JiaLi ophiolite hybrid belt（J-K）,Cuo qin-shenzha island arc （J₃-K₁）,Lunger-Gonbujiangda composite island arc （P,T,K）,ladakh-south Gangdise-xiachayu magmatic arc belt （J₃-K₁,K₂-E）,xigaz forearc basin （K）.The differences in stage of the tectonic movement along with a massive of volcanic and magma intrusion activities,and bring in richly ore-forming materials and ore-forming fluids.In this paper,tectonic evolution and magmatism as clues,thestudy of typical deposit as key,on the basis of widespread and profound collect-ing of former exploration data,summarized and analyzed the metallogenic regulari-ties,the metallogenic models,and divided the metallogenic series of copper deposits which formed in Mesozoic and Cenozoic.In the Gangdise metallogenic belt，the porphyry copper deposits and skarn type ore deposit are the major type,hydrothermal ore deposit in addition. Three ty- pes of deposits formed in the background of the Tethys sea evolution and contin-ental collision,the mineralization is inherited in age,the deposits have correlation in genesis,which lead to the unique metallogenic series.of the metallogenic belt. The four typical deposits which both have common and feature characteristics cover mainly deposits type,representing different geological background and metalgenesis.. distribution in different tectonic environment: dive-collision magmatic arc anddeveloping island arc would formed porphyry copper; Subduction island arc, magmatic arc formed skarn type copper. the main diagenetic-metallogenic events and magma-tectonic movement events are especially coherence and inheritance in time the outbreak of Metallogenic events is mainly in18¹2Ma,stretch after collision background; Second important age is50⁴0Ma,represent of collision environment; metallogenic events are occurred in whole Mesozoic,but in the backgroundof island arc-basin evolution,the forming of deposit have no special concentratedperiod,in addition,and the collision period has no obvious large-scale metallogenesis. The host rocks can be divided into carbonate build,clastic rocks build,and volcanic rocks build and pyroclastic rocks build.Ore-controlling magmatic rocks arecrust-mantle mixed type calcium alkaline series acidic intrusive rocks and volcanic rocks;post-collisional period potassium-super potassium calcium alkaline intrusive rocks. Ore-controlling structures are deep fault,the pushover-slide the structure,strike-slip tectonics,and small fracture,broken in with,contact belt;in deposits,rockbody,host build.Based on the research of metallogenic events and time,the structure,ore-controlling factors,consider that copper mineralization in the metallogenic belt roughlyexperienced three periods:（1） the sea-shell subduction metallogenic period,forming Mesozoic island arc skarn type copper deposits;（2） the main collision orogenic metallogenic period,forming collision magmatic arc type porphyry deposits;（3）post-collisional metallogenic period,forming skarns-porphyry metallogenic system,is the outbreak period of copper mineralization.On the basis of study on typical ore deposits,Xiongcun,Qulong,JiaMa,and summarizes the geological background,the tectonic evolution,ore-controlling conditions,the time and space distribution regularities of mineralization and other important aspects. Metallogenic Series in Gangdise metallogenic belt could be confirmedas the magmatism metallogenic series combinations,contain of three Cu-polymetallic deposits metallogenic series:（1） the Cu-Au es-ag metallogenic series relate to magma activity which caused by bilateral subduction （2） Cu-Mo-Au es-ag metallog enic series have relationship with shell/crust-mantle mixed intermediate-acid intrusive rocks formed in main collision period;（3）Cu-Mo-Au-Ag-Pb,Zn metallogenicseries dependence with post-collisional stage high potassium alkaline-calcium alkaline magma series. And then establish the metallogenic models under the corresponding mineralization area,in order to provide reference on ore-forming belt of ore-forming regularity study,further exploration and prospecting,resources evaluation.