| The main research work of alaskite uranium deposit in Gusu Province completed in eighty years of the last century,limited research means,ore-forming theory,finited search extent,researchful definition,research studies.In this paper.Study on deposit ore-bearing host-rock by petrology and mineralogy,geochemistry and uranium mineralization systematically summed up the mineralization geological characteristics of pegmatoidal alaskite type uranium deposit.discussed the electron microprobe chemical dating feasibility and significance in uraninite metallogenic epoch.Research shows,the ore-bearing host-rock is pegmatitic alaskite in Hongshiquan uranium deposit,it is wide heavy tabular invasioned nearby in anticlinorium axis that belong Longshoushanmt groups,unconformity invasioned in surrounding rock.Major elements,SiO2 content varied greatly?56.74%98.5%?in pegmatoidal alaskite,SiO2negative correlation with Al2O3,K2O,TiO2,MgO,Cao,TFeO,MnO,P2O5,rich in K and poor in Na?Na2O/K2O average value is 0.42?,belongs to aluminous rocks,alkaline granite series.Rare earth elements,the distribution pattern of the wild goose type,LREE/HREE=5.43,?La/Yb?N=0.869.58,light and heavy rare earth element fractionation is obvious,light rare earth enrichment,Eu heavy deficit,Ce mild deficit.Trace elements,similar to spider diagrams,strong enrichment in large stone elements Th,U,Ta,deficit of high field strength elements Rb,Nb,Ti,P,CE,Sr etc.Should be homologous to the product of magma evolution;also strongly enriched in U elements may provide uranium source for uranium mineralization in the area.The initial mean ratio of 87Sr/86Sr=0.80896,which indicates that the source of the rock mass is the source of the crustStudies suggest that Hongshiquan pegmatoidal alaskite type uranium deposit belongs to the whole rock type mineralization?U>0.01%?,uranium orebody shape of a vein,similar vein,lenticular and irregular shape,the ore is mainly including chlorite,biotite mainly blackening ore?rich?and hematite mainly red ore?poor?two types;the main uranium minerals uraninite,pitchblende,residual uranium black,uranium black and containing uranium hematite and containing chlorite uranium;uranium ore symbiotic combination comprises two types:uraninite-pyrite-molybdenite series and pitchblende-pyrite-galena series.The uraninite electron microprobe chemical dating age of acquisition is347.55Ma363.32Ma,coincide with the previous study of Luliang ore-forming period Variscan mineralization period?350210Maħ4978Ma?,that the method is applicable to the age of uranium mineralization in this area,at the same time that Variscan uranium mineralization occurs not only in Longshou mountain areas?alkali metasomatism type uranium deposit?,also occurred in Longshou mountain west region. |
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