| Anshan and Benxi of Liaoning Province (referred to Anshan-Benxi area), whichis rich in iron ore resources, is one of the most important iron and steel industrial basein China. Iron ore of the Anshan-Benxi area belonging to Precambrian banded ironformation (BIF), is the largest iron ore type in China and worldwide. Gongchanglingiron ore, which is located in the east of the Anshan salient, has rich reserves. Thesecond district ore of Gongchangling iron ore has rich iron ore in a large-scale, and isthe important supplier of Anshan Iron and Steel. For a long time, Gongchangling ironore has been attached a great amount of attenuations of the geologists and there havebeen a lot of researches on this iron ore. In2007, Liaoning Bureau of MetallurgicGeological Exploration discovered a new rich iron ore body, which contains50million tons of iron ore resources, including rich iron ore resources of34million tonswith a tenor of ore of up to63%.This thesis accompanied with the Countrywide Critical Mime Backup ResourcesProspecting Project based on previous research. Fifty-seven samples of the magnetitequartzite, magnetite-rich ore, amphibolite rocks, altered rocks and migmatitic granitefrom Gongchangling were collected, and their major elements, trace elements and rareelements are analyzed. Based on their geochemistrical characteristics, combined withthe previous research, the protolith of metamorphic rocks and migmatitic granite areinferred and constructed. Additionally, the forming material source and the cause ofmagnetite-rich ore are discussed. Furthermore, the mark and direction ofprospecting are proposed. The main results are as follows:(1) The protolith of the amphibolite rock is mid ocean ridge tholeiite, alteredrocks are formed from amphibolite rocks by hydrothermal alteration in late stage.(2) Mayu granite (older than2.5Ga) in the Gongchangling area is typicalsub-alkaline crustal derived granite, and the formation of magmatitic granite isattributed to partial melting. (3) The metallogenic material of the Gongchangling iron ore is mainly fromseafloor hydrothermal, which is rarely contaminated by continental clastic materials.In the ore-forming process, seawater may involve in the metallogenic hydrothermal.(4) In this thesis，we claimed that the formation of magnetite-rich ore isattributed to the deterioration of water hydrothermal. The iron of Magnetite-rich ore ismainly from magnetite quartzite, which is influenced by green-schist faciesmetamorphism. Magnetite-rich ore is formed with metamorphic hydrothermal.According to the types and metallogenic model of the Gongchangling iron, we haveproposed the marks and directions of prospecting. |
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