Characteristics Of Porphyry-type Ore Deposits And Ore-forming System Analysis In North Beishan Area, Inner Mongolia

This paper guided by the theory of Metallogenic System, started with generalstudy of mineral deposit, which included the essential geologic factors of controllingdeposits formation to preservation and metallogenic process. By integrated theelements of mineralization time, space, material, and transport, the authorcomprehensively discussed the porphyry metallogenic system in north belt of theBeishan Mountain, Inner Mongolia.The north belt of the Beishan Mountain was convergent continental margin,which belonged to the northern margin accretion zone of Tarim-Kazakhstan joint plate.With the Paleo-Asian Ocean plate subducted to Tarim-Kazakhstan joint plate, thePaleo-Asian Ocean gradually closed, and eventual led to continent-continent collisionorogeny of the Tarim-Kazakhstan joint plate and the Siberian plate. This evolutionmade the north belt of the Beishan Mountain became a beneficial area ofporphyry-type deposits formation.The author analyzed three typical deposits included Xiaohulishan porphyrymolybdenum polymetallic deposits, contrasted study of the deposit-level porphyrymetallogenic system like Xiaohulishan deposit, proposed that the mineralizationsystem was organic combined by the five subsystem: the metallogenic material supplysubsystem, the ore-forming fluid subsystem, the ore-forming energy subsystem, theore-forming spatial subsystem, and the post-ore change-preservation temporalsubsystem.Based on the typical ore deposits study, the author summarized the basicstructure and general characteristics of each subsystem in the north belt of the BeishanMountain convergent continental margin metallogenic system, established theprospecting model, mineralization network, metallogenic system structure of theregional porphyry deposits in north belt of the Beishan Mountain.The study results showed that NWW-NW and NE faults cross-cut to form agrid-like structure constituted the main framework of regional mineralization networkin the north belt of the Beishan Mountain, Inner Mongolia. Each structure joint wasbeneficial lithology and ore controlling place. All the discovered mineral deposits (orore occurrences) are located near the network framework.After divided the regional metallogenic regularity and metallogenic belts, the author summed up six prospecting criteria of porphyry type deposits in north belt ofthe Beishan Mountain, preliminary established the prospecting model of this typedeposits, determined the"point to region, surface to depth, follow in proper sequence"prospecting idea, proposed the technical method in search of porphyry-type oredeposits in this area.The author delineated three prospecting targets: Tianshuijing-LiushanshanMo-Au-Cu-Fe area, Erlegenwulawula-Wuzhuergashun Mo-Cu-Fe area andGaoshishan-Xiaohulishan Cu-Mo-Au-Pb-Zn-Rare Metal area, confirmed the mainmineral resources and ore deposits in each prospecting target. This study offers veryuseful reference for future prospecting work in north belt of the Beishan Mountain,and reflects the organic combination of the Metallogenic System and prospectingpractices.