The Determination Of The Ore-controlling Structure System And The Tectonic Stress Field Analysis Of Yin Keng Ore Field,Southen Jiangxi Province

Jiangxi Yudu Yinkeng ore field is located in the north eastern of east-west tectonic-magmatic belt in Nanling, in eastern of Yudu silver pit and southern section of Ningdou QingTong Yanshan period tectonic basin in southern Jiangxi.It’s geotectonic position is in twoNE-trending faults gripping plots within the crus of Wuyi terrane part in South China foldsystem. It is the ore cluster area of Au-Ag-Cu-Pb-Zn in the eastern of Gannan. The exposedstrata from Qingbaikou System, Sinian System of the Proterozoic to Devonian system-Permian System of Late Paleozoic and the Jurassic system of Mesozoic.It has been found thatthe main Au-Ag-Pb-Zn and other more expensive metal ores,is widely distributed andquantity,and it’s a is a huge mineral resources prospecting ground. Predecessors have done alot in the area of prospecting and exploration work and thematic studies, accumulated awealth of geological data for this study have provided favorable conditions.The author worked has achieved the following results based on five months fieldinvestigationsusing in Yinkeng ore field and analysis and laboratory the results of the fieldresearch:1According to the backbone of Yinkeng Orefield structural characteristics, the Yinkengore field backbone structure compared with regional tectonism that Yinkeng ore field hasexperienced three large tectonic movement, which related to mineralization was the NewChina Tectonic System.2.Studies suggest that Yinkeng ore field backbone structure belongs to the new structureof the Chinese system, and in the Yinkeng ore field are mainly developed NNE direction ofthe backbone structure, NWW direction of the Yangtze style rifting zone, NEE directionTarzan-style structure, basement early development SN direction of the folds and dense hackmanagement zone, NWW direction Yangtze style rift with ore-controlling structure for thetrunk, the latter concealed granite magma into the water and substrate formation mainlycomposed of metamorphic water hydrothermal fluids, Sinian System strata will bring to theore-forming elements enrichment and mineralization within the group structure, NEEdirection Tarzan-style structure also has some of the ore-controlling effect. And NNWdirection is constructed in this area is not developed.3.According to a preferred substrate wings fold occurrence calculate the stressorientation of each part of the fold, fold the stress orientation calculation performed. Synclinalfold bridge den get stress orientation from north to south is:148°∠18°â†'280°∠9°â†'91°∠19°â†'245°∠28°, that is, from NNW to EW then Nan Xixi to compressive stress changes. Celery den syncline stress orientation from north to south is:130°∠13°â†'81°∠19°â†'76°∠11°, that is, from the north west toEW change. The bridge sub-sub-pit pitsand celery are quantitative fold Ï€ diagram shows two sharp edges syncline to syncline.4. By Yinkeng ore field near the main structure and development of jointed Jointed pointmeasurements to analyze the data, to get these points towards joint rose diagrams and otherdensely jointed pole figure analysis joints preferred orientation. In a conjugate jointdevelopment of the geological point of the conjugate shear joints principal stress calculationmethod of the judgment of the principal stress direction, resulting Yinkeng ore field and stressfield of the trunk match. Ie basement fold near the EW compressive stress, the trunk near thenappe NW-NWW to compressive stress.5. Yinkeng ore field in the backbone structure determined system, based on the finiteelement method for the new China tectonic stress field simulation system to simulate got threetectonic displacement size, trunk tensile stress, maximum compressive stress, the minimumcompressive stress, shear shear stress, the stress and strain field direction changes thedirection of the results and other parameters. The first tectonic displacement, trunk tensilestress, the minimum compressive stress, shear stress is maximum in the third period to aminimum. The maximum principal stress places second phase construction of the largest inthe third period to a minimum. Contrast three tectonic stress field in the direction of rock andfault zone are similar direction and magnitude of the stress field changed little, but the size ofthe corresponding strain in the fault zone and the surrounding rock are significant differences,rock strain is small, strain large fault zone, and in the fault zone perpendicular to the extrusiondeformation associated with extensional strain.6. According to the NWW "Yangtze River" type analog characteristics of tectonic zone,that is, by a small compressive stress, and by the larger NE-SW direction tensile stress, easyto create favorable hydrothermal mineralization enrichment tensional fractures in latehydrothermal effect, easy to form deposits.