Study On Metallogenetic Law Of Precious And Non Ferrous Deposits In The Southeast Part Of Jilin Province

The southeast Jilin Province is located in the north margin of North China Plate,which is an important component part in the metallogenetic belt of north margin. There aremany mineral resources of precious and non ferrous metals in the area. Based on regionalmetallogeny and theory of terrane tectonics, we regarded metallogeny as core, regionalstructure-fluid-strata-metallogenic dynamics as lead line, metallogeny of precious and nonferrous metal as target. Combining analysis of typical deposits with analysis of geotectonicsetting and metallogenetic dynamics, associating macroscopical characteristics of ore beltswith microscopical natures of deposits, we determined geologic setting, metallogeny andore-controllign factors in the study area. Then every type of metallogenetic series andmetallogenetic medels were built and law of spatio-temporal distribution of metallogenywere concluded by us. At last, prospecting direction and strategic precinct were proposedalso.According to researching geologic setting of metallogeny, it was shown that theevolution of geotectonic setting went through three stages; they are Precambrian crustformation, late Proterozoic-Paleozoic paleo-Asia structural evolution, and Mesozoiccircum-Pacific superposed structural movement. Then we proposed that Archaeozoicgeologic body in the southeast of Jilin Province was a composite terrane Amalgamated byseveral middle Archaeozoic to late Archaeozoic terranes. It could be divided into twomiddle Archaeozoic terrans, four late Archaeozoic terranes and one early Archaeozoicterrane with the rule of terrane classification. Then we discussed their formation andevolution. It was thought that archaeozoic crust consisted of six individual terranes bygeology and geophysics. We considered that these terranes were amalgamated by "A"typesubduction during the late stage of late Archaeozoic. And the north district of study areawas a many-island ocean in paleo-Asia tectonic domain, and then it collided softly with thepaleo-crust in the south of Jilin Province. The compressure between them sustained toJurassic.The former geologists thought that there was an anticline or thrust structure in Laolingdistrict. We considered that it was a metamorphic core complex structure in this area withgeologic and geophysical methods. Especially we used the method that eliminated localaeromagnetic anomaly. We confirmed the geologic body under the core and wholemetamorphic core complex, then we discussed its formation and evolution and itsore-controlling role to gold mineralization. At last, it was thought that denudations weredifferent in Laoling district, so prospecting should start along major detachment fault.We thought that ore-controlling role of structure was the most important one amongthose of structure, strata, and intrusive rocks. It was proposed that there were two importantmetallogenetic epochs, that is Mesozoic and early Proterozoic. Especially the MesozoicYanshanian was the focus metallogenetic epoch for every type of deposit. Then we dividedthe study area into three metallogenetic belts controlled by deep fault (ductile shear zone),...