The Geochemical Characteristics Of The Geological Body Of Uranium Deposit In Baishun Ore-field

This paper preliminarily studies main factors of the main elements,trace elements,rare earth elements and stable isotopes of uranium deposits are studied in Baishun orefield.The main points are as follows:Geochemistry of main elements: Through the study of geochemistry of main elements,the normal granite rock?alteration granite?fragmentation rock?crushed rock?siliceous veins?rich ore process is as follow: alkaline components gradually decreased,and siliceous components gradually increased,the content of siliceous veins reached the highest,and then decreased,indicating that Si elements in the structural band distribution is uneven.By comparison of composition of eight geological bodies main elements and change rule,except for ultracataclasite,Al₂O₃,Na₂ O,K₂O,MgO,TiO₂,P₂O₅ have obvious positive correlation with SiO₂.TFe₂O₃,FeO and SiO₂ show a significant negative correlation;CaO and MnO content remains stable.Diabase composition is significantly different from other geological body contents.Except for diabase,other geological matter compositions and the surrounding rock have good similarity and inheritance.Geochemistry of trace elements: Highly compatible elements Cr,Co and Ni content are very low in normal granite surroundings,altered granites,fractured rocks,granulites,crushed rocks,siliceous veins,rich ores,fluorite and calcite,which are quite different from other highly compatible elements like enriched Cr,Co,Ni.These highly compatible elemental components are mainly derived from granite rather than mantle,suggesting that the ore deposits and metallogenic hydrothermal fluids in the Baishun ore deposit may come from the surrounding rock granite.Geochemistry of rare earth elements: geological characteristics of rare earth elements can be divided into four categories: 1).Normal granite,alteration flower rock,fractured rock,granite,fluorite and calcite curve is right-leaning.light rare earth element is enriched.EU shows negative anomaly,and europium loss is obvious.Light and heavy rare earth elements have high degree of fractionation.2).Rich ore: Total amount of rare earth elements is the highest among all geological bodies;EU shows negative anomaly,and europium loss is obvious;Different from other right-leaning curves,The characteristic curve of rare earth elements of rich ore is close to horizontal line,indicating the trend of enriched rare earth elements and weakened fractionation between light and heavy rare earth elements.3).Siliceous veins and crushed rocks: both curves are right-dipped and total amount of rare earth elements is the lowest;Eu shows negative anomaly,and europium loss is obvious;Different from other curves,both show significant Ce loss.4).Diabase: diabase rare earth distribution model curve is right-leaning,but no Eu anomaly,which indicates that its source and the remaining several geological bodies are essentially different.The characteristics of fluorite and calcite rare earth elements show that the ore deposits and hydrothermal fluids in the uranium deposits are mainly derived from rock granites whose Eu depletes relatively.Stable isotopes: hydrogen and oxygen isotopic composition characteristics,Baishun ore uranium ore mineralization of hydrothermal fluids mainly come from the groundwater by formation of precipitation,and perfroms exchange reaction of O isotope with surrounding rocks;calcite carbon and oxygen isotopic characteristics indicate that the carbon in the hydrothermal fluid is derived from granite and mixed with part of the deposited organic carbon.