مدلسازي ژئوشيميايي در كانسار طلاي اپي ترمال ساري گوناي، استان كردستان

چكيده انگليسي :

114Degree DoctorTitle Geochemical Modeling in the Sari Gunay Epithermal Gold Deposit Kordestan Province NW IranAuthor Hamid GeranianSupervisor Seyed Hassan TabatabaeiDepartment Mining EngineeringDate July 26 2015Abstract In mineral exploration projects drilling is the most important yet expensive discoverytool Drilling locations are usually selected based on surface anomalies A surface anomalymay be achieved from a certain geological geophysical or geochemical explorationdataset Drilling location can also be identified from integrated analysis of variousexploration layers Apart from integration methods modeling methods between surfacedata or subsurface data to identify borehole locations are also introduced and used in thisresearch This proposed method could increase the probability of interesting the offeredboreholes with subsurface mineralization Sari Gunay epithermal gold exploration datasetsare used to test the proposed model Sari Gunaiy deposit is located in the southwest of Kordestan province NW Iran There aretwo epithermal gold mineralization zones at Sari Gunay and Agh Dagh hills Detailedexploration has been completed at the Sari Gunay hill but the exploration at the Agh Daghhill is still in its preliminary stage Epithermal gold mineralization in these two hills is lowsulfidation in character The mineralization is mostly hosted by fragmental brecciated sub volcanic rocks of the Miocene age The dominant lithological units of study area are daciteand andesite porphyries diatreme tuff breccia and sub alkaline lithic porphyry rocks TheSari Gunay hill with a resource of 120 130 Mt at 2 g t Au is the largest ever discoveredgold deposit in the Middle East In this research quantity and quality modelling methods are used to model subsurface goldmineralization In the quantity modelling three mineralization parameters such as Mean Sum and PI were modeled continuously by multivariate regression MR and supportvector regression SVR methods The PI parameter was also modelled discontinuously bydiscriminant analysis DA and support vector machine SVM methods The resultsobtained from continuous and discontinuous modelling identified four important goldmineralized zones at the Sari Gunay hill Agh Dagh hill a faulted zone between Sari Gunay and Agh Dagh hills and in the northeast of the Sari Gunay hill The RBF nu SVRfunction produced the best results for all the four identified mineralized zones incontinuous modelling whereas in discontinuous modelling RBF nu SVM functionproduced the best results for Sari Gunay and Agh Dagh hills and the LDA function for thefaulted zone The achieved results indicated that the functions of the SVR and SVMmethods because of minimizing the structural risk were produced better modelling resultsthan the functions of the MR and DA methods with less empirical risk The maps obtainedby Mean parameter and Sum and PI parameters could be used to design the drilling areaand the density of drilling grids respectively In quality modelling methods the combination of geology data and surface and subsurfacegeochemical data were used to model the subsurface gold mineralization Fractal positiveand negative geochemical anomalies and geochemical zoning methods were used for thispurpose The results of the fractal modelling methods showed that blocks with very high

گرانيان، حميد

مدلسازي ژئوشيميايي در كانسار طلاي اپي ترمال ساري گوناي، استان كردستان

MR , SVR , DA , SVM , فركتال , آنومالي هاي ژئو شيميايي مثبت و منفي , منطقه بندي