Metallogenic characteristics of superimposed deformation and mineralization of Dahongliutan granite-pegmatite type lithium deposit belt in West Kunlun,Xinjiang:Constraints from ore structure,3D imaging technology and chronology
The granite pegmatite ore deposits are products from continental evolution,which are easily influenced by subsequent geological processes such as magmatic,structural and metamorphic activities that easily lead to a superimposed deformation and mineralization of them.This superimposed mineralization not only can reactivate the original mineral bodies but also might introduce new ore-forming materials.Analyzing the superimposed mineralization process of the granite pegmatite-type ore deposits can yield comprehensive exploration criteria and facilitate strategic mining deployment in potential ore cluster areas.The Dahongliutan granite pegmatite lithium ore belt in the West Kunlun of Xinjiang is one of the important rare metal pegmatite mineralization belts discovered in recent years.Through detailed field surveys,we have discovered that the Dahongliutan granite pegmatite lithium ore belt preserves detailed records of a late-stage ductile superimposed mineralization where fine-grained spodumene pegmatite veins crosscut early-stage coarse-grained spodumene pegmatite veins.By utilizing CT three-dimensional scanning technology on the drilling core,we found that the spodumene with significant overall volume contents occurred within the strongly deformed zone.The main body of ductilely deformed spodumene pegmatite consists of a'bookshelf'structure spodumene,a'mica fish'structure lepidolite,and recrystallized quartz flow bands.The U-Pb dating of the niobium-tantalum minerals in the ductilely deformed spodumene pegmatite demonstrated a late superimposed mineralization event at ca.193Ma.In situ Rb-Sr dating on the lepidolite with'mica fish'structure also indicated a similar age around 195 Ma.The aforementioned evidence supports a superimposed alteration and mineralization event postdating the widely occurring 212～206Ma(U-Pb dating of niobium-tantalum-iron minerals)mineralization event in this region.Considering the regional tectonic background,we speculate that detachment faults caused by late-stage magmatic doming resulted in the secondary ductile deformation of earlier-formed pegmatite and surrounding rocks.Thus,it can provide a certain scientific guiding direction for mineral exploration deployment in the Dahongliutan region.
West KunlunPegmatite Li depositSuperimposed mineralizationOre structure
万方数据
维普
