Lithogeochemistry Of Granites And Associated Uranium Mineralization In Que’er Mountain

Uranium, as a kind of important mineral resources, attached more and moreimportance to its development and utilization. According to the1:2000regionalmeasuring data, we found there is a granite belt which is rich in radioactive mineralsin the area of Que’er Mountain, and also found the car gamma ray spectrum highvalue, uranium mineralization point and abnormal points. On the basis of above all,we worked out the reconnaissance traverses and key areas in the field, then didgeological survey and retrieved rock samples for laboratory analysis. Analysised thecorresponding data, made a few maps of the correlation analysis, summarized themineral composition, mineral and trace elements characteristics and isotopiccharacteristics. Compared the Que’er Mountain’s lithogeology and geochemistrycharacteristics with the corresponding characteristics of the rock mass of southuranium-bearing granite, then discussed the uranium mineralization of the Que’erMountain.The rock mass distribut in the area of Zhuqing town in Sichuan province, whichis in Que’er Mountain, emplaced in the deep fractures of the triangle zone in theintersection area between the Dege-Xiangcheng big fault and the Ganzi-Litang fault,where the slate and metasandstone which is in the period of Permian and upperTriassic, it’s overlain unconformably by the Paleogene sediment cover. Rocks appearirregularly in the form of batholiths, have two basical kind of lithology, namelymonzonite granite and syengranite granite, and the former are more abundant,generall have the change characteristics as follows, the more inner we get, the higheracidity and bigger particle size the rock had. In the rocks fine grain and porphyriticxenoliths could be found, the lithology of xenoliths are similar to the Dongzhongda monzonite granite. Surrounding rocks are silicification and hornstonization etc., theouter contact alteration zone has a width of about one hundred metres, mostly arehornstone, also has andalusite hornstone in the east, in the southeast has a littleskarnization.The Que’er Mountain has two parts: Indosinian rock and late Yanshanian rock.There is a uranium mineralization point in the Indosinan rock at Zheda channel,Maisu country, Dege town: Zheda channel Molybdenum mineralization point, it’suranium molybdenum type of uranium mineralization point,the magmatic activity isvery complex, Indosinian Yipu hornblende monzonite granite and Jicuoxiama biotitemonzogranite emplaced in the early days and Yanshanian Que’er mountainporphyroid monzonite granite emplaced in the later period, and a group of dikeswhich were controned by NE-NEE trend faults emplaced the Indosinian rock massand its outer contact alteration zone, these later period dikes have a directlyrelationship to the mineralization,the mojar types of dikes are pegmatite dike, apliticdyke, biotite actinolite dike, lamprophyre dike and diorite dike.By means of sampling and analysis studying by the numbers in the area ofQue’er Mountain, we found the rock mass feature is rich of silicon, potassium,aluminum and poor in magnesium, titanium, calcium, sodium, belong to the alkalinegranite. The content analysis values of Silicon dioxide and potassium dioxiderelationship discrimination shows that most of the Que’er mountain rock samples fallin the area of high-potassium calc-alkaline series, also the alkalinity ratediscrimination shows the samples are in the range of alkaline series or calc-alkalineseries. Besides the rock mass has a high content of aluminum oxide and potassiumoxide, the content of titanium oxide, iron oxide, manganese oxide, calcium oxide andphosphorus oxide is lower, all those shows the characteristics of peraluminous granite.From the cause of formation,the rock has the features of S-type granite.The rare earth elements of granite in Que’er Mountain shows a high gross and awidth variation range, the rare earth elements partition formation is right deviation,the differentiation degree of heavy rare earth elements and light rare earth elements isbig, meanwhile displays a strong loss of europium, seen from the results of traceelements analysis, this rock mass is rich of rubidium poor of strontium granite, and inthe trace elements partition formation is right deviation, relative to the original mantle,the rock strongly loss barium, phosphorus, potassium, titanium and enrich plumbum,thorium, tantalum, neodymium, samarium etc., among them, the loss of barium, titanium may reflect that in the diagenetic processing,plagioclase, apatite and titaniumiron ore are separately crystallization.The rubidium-strontium isotope analysis of the rock determine the information ofthe rock is late Yanshanian, but when we overfitting the isochrone for the sampleanalysis results, we found that the granite sample in the north of Que’er Mountain hasa significant influence of the isochrones overfitting, that’s to say,the fault in the northnamed Ezhi-Zhuqing fault belt conducted the late reformation to the rock made therubidium-strontium system should have closed changed, it made a fake isochroneduring the process of isochrones overfitting. And the water sample isotope analysisresults of the Que’er Mountain’s ford shows that the whole area of water supplies areconcerned with the atmospheric precipitation, and from the analysis results of oxygenisotope of the hotspring, the hotspring water in Zhuqing area is obviously has moreheavy isotope than Que’er Mountain area, on the one hand shows that the runoff ofthe condition made different extent of isotope exchange between water and rock, onthe other hand, it may caused by the different a between the two area.Compared the corresponding feature with south uranium-bearing granite, we canfind that, both Que’er Mountian and south uranium-bearing granite rock have similarcharacters in mineralogical, lithogeochemistry, trace earth elements, Que’er Mountaingranite rock is consistent with the basic characteristics of uranium mineralizationrock,Seen from the structure environment, source rock, invading time of Que’erMountain rock, the structure conditions are good for the uranium mineralization.That’s to say, this rock has some of the uranium mineralization potential and themineralization vision is significance. But in some ways, it’s a little different from thesouth uranium-bearing granite, the reason may refer to their individual complextectonic environment.