Study of the Characteristics of Mass Transfer During the Ore-forming Process of High-grade Iron Ore in the Gongchangling Iron Deposit,Liaoning
As the largest and the only BIF-hosted high-grade magnetite iron orebody with industrial mining value in China,the metallogeny of the Gongchangling iron ore is still controversial.In this study,we collected typical BIF and high-grade ore samples from the No.4 iron ore layer and analyzed their chemical compositions.Conse-quently,we determined the elemental changes during the formation of high-grade iron ore using mass balance calculations,and therefore the following conclusions are received.For the major elements,Fe2O3 is strongly enriched,however,SiO2 is depleted,accompanying with the migration of alkali and alkaline elements(e.g.,Na,K,Ca and Mg),which are more active in geochemical mobilization properties.P2O5,BaO,and Cr2O3 are relatively less enriched,and this is probably related to the hydrothermal fluids which contributes to the for-mation of the high-grade iron ore;For trace elements,some high field strength elements(HFSE),such as Nb,Ta,and U are enriched,whereas Ce,Th,and Zr are depleted,and Hf and Ti remain unchanged;In terms of some large ion lithophile elements(LILE),Ba and Cs are enriched,however,Rb and Sr are depleted.This suggests that the Nb-Ta mobilization in both high-grade iron ore and the altered rocks are caused by the same ge-ological event;For rare earth elements(REE),the light REE(e.g.,La,Ce,Pr and Nd)are distinctly de-pleted,whereas,the heavy REE are enriched.In summary,the genesis of the Gongchangling high-grade iron ore is probably related to the granitic magmatic events.
BIF-hosted high-grade iron oreelemental mass transfermass balance calculationgenesis of high-grade iron oreGongchangling
万方数据
维普
