Metallogenic-geological Characteristics And Prospecting Prediction Of Gold Mineralization Zone In Southwestern Part Of Liaoning-Jilin Rift

The gold mineralization concentrated area of the southwest part of Liao-Ji rift is Liaodong large gold deposit concentration area output,this paper on the basis of analyzed the Baiyun gold deposit Taoyuan gold deposit and Taziling gold deposit metallogenic condition,geological features and prospecting marks,predicted the localization of the gold concentrated areas in the southwest part of Liao-Ji rift.Achievements:(1)The gold auriferous deposit concentrated region in the southwest part of Liao-Ji rift were produced in Gaixian group and upper of Dashiqiao group,controlled by the nearly east-west fold,Indosinian-Yanshanneutral-acidic dike accompanied with gold,silver,lead,zinc ore body output,silicification and potassium feldspathization closely associated with gold mineralization,but they didn't happen at the same time,K-feldspar formed slightly earlier,silicide formed after the potassium feldspar.(2)the metallogenic regularity of the gold mineralization concentrated areas in the southwest part of the Liao-Ji rift is the following aspects:a)sedimentary metamorphic mineralization period,original sedime-ntary ore source layer ofLiaohe period;b)indosinian to yanshanian of Mesozoic magmatic activity is an important metallogenic region;c)on the space on either side of the main distribution of gold deposits in the rift axis fault depression,The parallel faults and Paleoproterozoic strata spatial distribution control,The gold deposits occurrence in the sedimentary rocks construction of upper clastic rocks in Liaohe Group.(3)Summarizes the ore prospecting indicators:a)Rock indicators:schist or phyllite with interlayers of thin quartz schist,epidolerite and leucoleptite,marble,tremolite,graphite epidolerite tremolite schist and marble.b)Structural indicators:nappe structure areas,bed-parallel faults in potential layers,detachment structures and intersected parts with faults in other directions,complicated antiformal syncline structures,convolute folds,rapid changes of layer occurrences,brittle fractures in ductile shear zones.c)Rock mass indicators:developmental areas in rock masses and its interior and exterior contact zones.d)Mineralization indicators:silicification,potassium feldspathization,pyritization and discoloration alteration.(4)Two prospecting area are selected,respectively for the Wujianfang gold polymetallic ore prediction area and Jiajiaweizi gold polymetallic ore prediction area.