Granites Characteristics And Uranium Mineralization In Baishuizhai Of The Xiazhuang Uranium Field

Baishuizhai area exposed of about 2km2 and located in the northwest of the Xiazhuang uranium field, and the mineralization superimposed hydrothermal activity center site in the area. From the petrographic, geochemical focus on Baishuizhai granite systematic study to analyze the structural environment and causes, and analyze structural characteristics of the study area, wall rock alteration features, wall rock alteration and uranium mineralization, and to explore white kiosk granite, rock geochemistry and uranium mineralization.It shows the characteristics is high-silica,high potassium,high- alumina, alkali-rich, iron magnesium ratio, and peraluminous granite. This shows that the original magma crystallization differentiation is not strong. The light rare earth enrichment significantly,the LREE and HREE are obvious fractionation. The average ratio of CaO/Na2 O of Baishuizhai rock mass is more than 0.3. The TFeO+MgO+TiO2 content 2.09% ~ 3.06% are less than 4%. The source rock is mainly composed of clay. The Rb–(Y+Nb) tectonic discrimination diagrams of the Baishuizhai rock mass and the Xiazhuang granite are located in the post collision granite area. This means Baishuizhai rock mass was formed in the crustal movement. It may formed by the Paleoproterozoic metasedimentary rocks low degree partial melting. This kind of granite was formed collision motion in the late Indosinian.The granite of Baishuizhai area mainly by the NE trending structures, N EE- NE and NWW, near East-West three groups of structural control. The rock hydrothermal alteration is mainly a silicification, potash feldspathization, alkali metasomatism, sericitization, chloritization, hematitization, pyritized fluoritization.Ore minerals are pitchblende, uranium stone, titanium uranium, thorium stone and calcium silicon uranium, autunite, copper uranium mica and other secondary uranium minerals.The magmatic activity, tectonic and uranium mineralization in combination in study area can be divided into three tectonic hydrothermal alteration. The first uranium rich hydrothermal activities were formed in the late stage of fine grained granite intrusion. The early stage is high temperature silicon rich silicon acid solution. The mineralization type is mainly pitchblende and microcrystalline quartz. On this basis, the mesotherm uranium rich alkaline hydrothermal formed the alkali metasomatic rock. The mineralization type is mainly pitchblende alkali metasomatic hematite type. In the third, low temperature silicon rich, uranium rich acidic hydrothermal formed. The mineralization type is mainly pitchblende and microcrystalline quartz.And Uranium Metallogenic closely related mainly ripidolite, brunsvigite, and pycnochlorite, the formation temperature for different occurrences of chlorite is between 172.81℃~228.49℃, average on 202.08℃, and mineralization during hydrothermal making rock-forming minerals mica, feldspar eclipse becomes chlorite, and activation of uranium under reducing conditions late neonatal adsorption of uranium alteration minerals.Baishuizhai granite magma evolution in the late formation of rock uranium enrichment, uranium mineralization occurs in the contact zone of rock and rock and faults of the junction.The early Yanshan granite formed uranium activation area, during the late yanshanian the Ultra acidic granite invaded. The study area of high uranium granite formed. After the water rock interaction of catalysis, formed alteration minerals of the early stage. The inert uranium released into active uranium, atmospheric precipitation leached the activation uranium. The rising catalyst hydrothermal fluids which enrich the CO2 and F produced recombination action, the active uranium formed uranium minerals in the reducing environment, and were adsorbed by the new generated of altered minerals. The gathered, conduction, transportation and storage of the uranium minerals completed by NE trending fault belt, and were connected by the complex EW trending tectonic zone and the NEE trending tectonic zone. At last, these uranium minerals formed the uranium deposits and the uranium ore-spot.