The Geochemical Characteristics And The Metallogenic Evaluation Of Tiebanjing Basic-ultrabasic Intrusion In Inner Mongolia

The Tiebanjing basic-ultrabasic intrusion is located in the western section of the beidashan uplift which in the northern of AlxaBlock in Inner Mongolia,extendingabout0.12km2,which formed on the environment.continental rifting of of AlxaBlock and it is favorable for metallogenic belt for Cu-Ni sulfide deposits.the intrusion of Tiebanjing is mainly composed of Pyroxene-peridotite,olivine-pyroxenite,gabbro.The intrusion develops a large amount of metallic minerals,and metal minerals mainly include magnetite,pyrite nickel pyrrhotite pyrite,etc.the intrusion develops a large amount of Cu-Ni minerals,likely to have the potential of forming Cu-Ni mineralization.In this paper,I have some research on metallogenic age,mineral,magma sources using some mothed of petrology,mineralogy,petrochemistry,to discuss the magmatism ore-forming process of the Tiebanjing intrusion,lithogeochemistry,petrogenic age et al,discussing on magma source,diagenetic processand mineralization potential.Conclusions are as followed:The Tiebanjing basic-ultrabasic intrusion has the higher content of MgO,can amount to 38%,the content of Na2O?Al2O3?K2O?CaO is lower,hosting obvious characteristics high magnesia and poor alkali poor aluminum.m/f is 8.5~19.3%.The intrusion of Tiebanjing belongs to the type of Magnesian ultrabasic rock.The intrusion has undergone strong alteration and changed into Serpentinite.The content of ?REE is very low(?REE=0.24�10-6~0.66�10-6),light and heavy rare earth fractionation is not obvious(LaN/YbN=0.32~5.57).Most of rocks are relatively enriched in large ion lithophile elements(Rb?K?Sr)and depleted in high field strength elements(Th?Nb?La?Ce?Zr),and has Th?Nb?Ce negative abnormality.87Sr/86Sr(0.7115~0.7138)ishigherthanthatofthemantle(0.704).Through the study ofLA-ICP-MS zircon U-Pb isotopic geochronology,the data can devide intotwo parts.One parts is older than 800 Ma of zircon,which shows the characteristics of inherited zircon captured from crystalline basement;the other part shows that the age of The Tiebanjing basic-ultrabasic intrusion formed is 473�3Ma,which is relative to continental rifting of AlxaBlock at Middle Ordovician.The Tiebanjing basic-ultrabasic intrusion is located in the continental rifting belt of AlxaBlock,which is favorable for mineralization.The Tiebanjing intrusion is different from jinchuan intrusion,similar to The Gansu Jianchaling intrusion.The Jianchaling intrusion don't form sulfide ore in the process of magmatic differentiation,and later sulfofication occurs due to the addition of sulphur in the external to form Cu-Ni sulfide deposits.The geochemical characteristics of the Tiebanjing intrusion is similar to that of the Jianchaling intrusion,indicating have the potential of forming Cu-Ni mineralization.the potential area of finding ore is in the deep or the contact zones of intrusion and stratum,especially the contact zones where is rich of Sulphur.