| A complex body in a district of Lin County,Shanxi,has been exposed in the west wing of the middle section of Luliang Mountain.Because of its typical alkaline rock type,it has been paid attention by geoscience circles.In order to study the distribution rule,occurrence state of radioactive elements uranium,thorium and potassium of alkaline complexes in a certain area of Lin County,Shanxi,and the environmental impact of radioactive radiation,the project"Lanxian Alkaline,Shanxi Province The sub-project"Investigation of radioactive minerals in rock niobium,rare earth and radioactive minerals""Lin County,Shanxi Province"project,through the combination of field ground gamma spectroscopy and indoor rock slice microscope,the The distribution characteristics of potassium are studied.The environmental radiation assessments of theγradiation absorber rate,annual effective dose equivalent,and equivalent radium concentration were conducted in the study area.The research results are as follows:1.The surface gamma-ray spectrum measurement was used to sweep the surface of the study area to delineate the distribution range of uranium,thorium and potassium elements.The maximum values are 34.35×10-6,63.58×10-6,16.04×10-2,respectively;the encircled anomalies are developed in the middle and south of the study area,with good connectivity in the middle,mainly distributed continuously from east to west,and points in the south Distribution,poor connectivity,bead-like distribution from north to south;the potassium anomaly area is widely distributed in the west,north,and south of the study area,and is distributed discontinuously;combined with ground surveys,it can be seen that the uranium and thorium anomaly areas are mainly distributed In the dolomite pyroxene rock,nepheline syenite,neon syenite,and breccia.Potassium anomalies are mainly distributed in biotite pyroxenite syenite,diaphyllite syenite,nepheline syenite,neon syenite,pseudo white garnet syenite,and pseudo white garnet.2.Based on the relative stability of the geochemical properties of the thorium element,the ancient uranium element content was calculated.The high-value area of ancient uranium content is generally consistent with the current uranium content distribution,indicating that there is basically no chemical or mechanical migration of uranium elements in the rock mass of the uranium anomaly area.3.By comparing and analyzing the contents of uranium,thorium,and potassium in the rock masses at different intrusion periods,it is found that the content of radioactive elements in the first phase of the diorite,the second phase of the neon syenite,and the fourth phase of the nepheline syenite accord with the intrusive age The newer,the higher the content of the law;and the third-stage intrusive body contains Xiaxi syenite and the fifth and sixth stage breccia rough rock and breccia loud rock do not meet this law.It is inferred that the diorite,neon syenite and nepheline syenite did not melt and react with the surrounding rocks during intrusion;During the intrusion of breccia rough rock and breccia rock,the magma melts and reacts to the surrounding rock,or the melting and reaction are not complete,and the composition of the magma changes,which causes different contents of uranium,thorium,and potassium in the rock mass.4.Microscopic analysis of the rock slices in the uranium,thorium,and potassium anomaly regions revealed that minerals rich in uranium,thorium,and potassium were found.The mineral composition and content are as follows:apatite and sphene are the main occurrence minerals in uranium and thorium anomalies,and the total amount of apatite and sphene in breccia rough surface rock is（5%～13%）,black Apatite（4%～5%）,sphene（3%～4%）in dolomite rock,nepheline syenite（1%～5%）,neon syenite（spermite）1%～2%).Orthofeldspar,nepheline,dolomite,biotite,diasporite,dolomite,and dolomite are the main potassium-occurring minerals in the potassium anomaly area,containing syenite（50%～55%）,nepheline（30%～35%）,pseudo-white garnet mid-diaspermite（4%～5%）,orthoclase（50%～60%）,white garnet（10%）,black Mica pyroxene syenite syenite（85%～90%）,dolomite（10%～15%）,pseudo-eugenite syenite syenite（65%～80%）,neon syenite（45%～50%）,nepheline（14%）.5.Based on the specific activities of 226Ra,232Th,and 40K in the rock,the gamma radiation absorber rate,annual effective dose method,radium equivalent activity,and internal exposure coefficient were calculated,and the environmental radioactivity radiation was evaluated in the study area.Studies have shown that theγ-radiation absorber rate of breccia rough rock,nepheline syenite,and neon syenite in the uranium and thorium anomaly regions is higher than the nationalγ-radiation absorber rate,and the dolomiteγ-ray absorber rate Lower than the national gamma radiation absorber rate.Theγ-radiation absorber rate of pseudo leuconite,biotite pyroxenite,pyroxenite-bearing syenite,and pseudo-eucryptite syenite in the potassium anomaly region is higher than the nationalγradiation absorber rate,and other non-abnormal The area corresponding to the zone belongs to the safe zone. |
