| Yunnan Jinning Eshan granite is located at the southern end of the Kang Dian axis and the western margin of the Yangtze plate.The area is more than 200 km2,which is formed in the period of Jinning(820~860Ma).The research area has exposed many ore bed points such as tungsten,tin,molybdenum,copper,lead,zinc and iron,but no scale endogenic mineral deposit have been found.In this paper,we take the Eshan granite(northern)as the research object.From the regional scale,the erosion events of rock mass have been analyzed,and the emplacement mechanism and emplacement depth are preliminarily determined by using the analysis results of constant elements,trace elements,rare earth elements and chronology,combined with the field investigation;Through the calculation and analysis of petrology and rock mass CIPW,quartz minerals are selected to estimate the denudation depth of the thermometer,and the distribution of ore bearing rock and ore deposits at home and abroad is summarized and compared with the denudation data of rock mass,analyzing the changing preservation conditions of different types of ore deposits,the prospecting direction has been clarified for future exploration.Through summing up the research area,it is presumed that the rock mass in the study area mainly experienced the lifting and transformation of Jinning movement to Caledonian Indosinian Hercynian movement to Yanshan movement.In the field investigation of the structural characteristics of the Eshan granite and surrounding rock,the emplacement mechanism of the rock mass is preliminarily determined by the analysis of the constant elements,trace elements,rare earth elements and chronology,and the mechanism of the emplacement mechanism of the rock mass is the mechanism of the expansion of the passive rock wall and the post balloon expansion and the position of the post balloon.At the same time,compared with the identification mark of the emplacement depth,the rock mass is in the shallow-middle belt depth position.The CIPW calculation found that the content of corundum was higher,only a few samples were less than 1%,which did not conform to the conditions of the artificial granite pressure meter.The petrology microanalysis found that the three units of the hornblende in the EME granite slope,donkey village and mocra are poorly developed or undeveloped,It is difficult to calculate the pressure of the balanced mineral with the biotite pressure gauge.So the quartz mineral fluid inclusion pressure gauge is used to obtain the denudation parameters,and the range of diagenetic pressure(31.5 MPa),average(60.47 MPa),and the depth of denudation(4.43 km ~ 7.38km)and the average depth(6.22km)are obtained.Through comparison and evaluation,this result has certain credibility.The metallogenic model is used to reflect the metallogenic regularities of typical endogenetic deposits in the study area,and to compare the erosion depth of the rock mass ith the metallogenic depth range of different types of ore deposits: the depth range of hydrothermal vein type deposits(0.5~4.5 km),the common depth range(0.5~5 km),so the deposit conditions are poor.The shallow metallogenic site of the rock mass is basically eroded and depleted,which is one of the important reasons why the scale deposit has not been found in this area.The metallogenic depth of the porphyry type(Mo,Cu)in the East(E)section of the East(1.0 ~ > 10Km),and the common depth range(1~ 6 km);compared with the denudation parameters,the porphyry type(Mo,Cu)deposits still have some preservation,and have a certain prospecting potential.The range of metallogenic depth of the skarn tungsten deposit in the middle(C)section(1.5 ~40km),and the common depth range(1.0 ~ > 10km);therefore,the skarn type deposit has a larger extension range and has a good potential.The transverse distribution rule of ore bodies and ore deposits is synthesized.Delineating the eastern part of the rock mass(E)and the middle part(C)is a potential exploration target area. |
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