Age And Genetic Research Of Typical Gold And Iron Deposits In Jueluotage Area, Eastern Tianshan

Jueluotage area, located in Eastern Tianshan, is an important metallogenic belt in China. Gold, iron, copper and other types of ore deposits have been found in this region. The metallogenic epoch differs about tens of million years with different gold deposits within the same ductile shear zone and some gold deposits are multi-stage mineralization. Hongshi gold deposit locates in Qiugemingtashi-Huangshan ductile shear zone. Ar-Ar dating was the only method been used to study the metallogenic epoch of Hongshi gold deposit in such a complex metallogenic belt, the metallogenic epoch should be confirm by using various methods. In this paper, Ar-Ar and Rb-Sr dating are combined to study the metallogenic epoch of Hongshi gold deposit. The ore genesis is studied by combinning geochemistry of mineral deposits. Hongyuntan iron deposit locates in Aqishan-Yamansu volcanic rock belt, intermediate-acidic intrusive rocks were widely developed in mining eara. Volcanic hydrothermal type and hydrotherma metasomatic type are the main understanding on ore genesis of Hongyuntan iron deposit. In this paper, the metallogenic epoch and genesis are studied by lithogeochemistry, isotope geochemistry and isotope chronology.The main achievements about Hongshi gold deposit and Hongyuntan iron deposit are as follows:1. Geochemistry of ore deposit shows that ore forming material came from deep mantle; early stage of ore-forming fluid were metamorphic water mixed with magmatic water, and later with the participation of atmospheric water.2. Isotope chronology study shows that the ore sericite Ar-Ar age and Rb-Sr isochron age of fluid inclusion in quartz are the same, indicating that the ore-forming age of Hongshi gold deposit is 257-258Ma, belonging to Late Permian.3. The mineralization of Hongshi gold deposit was controlled by right strike-slip shearing, which happened in late ductile shear deformation of Qiugemingtashi-Huangshan ductile shear belt. The ore deposition occurred during the lifting of the shear zone, which happened after the right strik-slip shearing.4. The intrusive rock in mining eara of Hongyuntan iron deposit has the characteristics of island arc granite, reflecting that the iron deposit formed under the oceanic crust subduction tectonic setting. The mineralization process lasted for nearly 20 million years, the main metallogenic epoch was about 309.7Ma.5. The iron ore-forming materal came from deep earth; ore-forming fluid were related to the magmatic water, and also with the participation of atmospheric water. The ore formed by volcanic deposition and hydrothermal modification, belongs to volcanic sedimentary-hydrothermal modification type of iron deposit.