Fractal Analysis Of Terrestrial Gamma Ray Spectrometry In Jinshiling District Of Chenzhou,Hunan

At present,the use of nuclear energy in China is more and more extensive,and the relative demand for uranium is also increasing.Both in prospecting and in radiation protection,people are paying more and more attention to the use of nuclear energy,and the methods of measurement are emerging in endlessly.There are many methods to deal with these data.It is an urgent problem for people to find a suitable method to find the lower limit value of the anomaly and draw the abnormal area.This paper is mainly aimed at the analysis of the content of U,Th and K measured by portable Gamma-ray energy spectrometer in Jinshiling lead-zinc uranium polymetallic mining area.By analyzing and comparing,we find a suitable method to find the lower limit value of uranium content anomaly,the traditional method deals with the value by adding the mean value to 2 times the mean square variance as the abnormal lower limit value.If the mean value plus mean square deviation is taken to get U=8.369ug/g and then the fractal theory is used to process the value,the lower limit of uranium content anomaly is 3.65ug/g and 3.10ug/g respectively by using the fractal content gradient area method and the gradient anomaly point method.The following conclusions were drawn:(1)Fractal theory transforms fractal objects and different interval scales.The results show that the difference of the lower limit value of uranium anomaly is much smaller than that of the traditional method.On the other hand,it shows that the fractal structure law of geochemical anomaly is of universal significance.(2)The distribution of U content in this area has two fractal characteristics,the first fractal dimension is very small,which represents the first geological and background values.The second fractal dimension value is larger,which represents the obvious later geological action,and there is a large potential fault.The fractal critical value can be used as the lower limit value of uranium content.(3)The results obtained by fractal theory are smaller than those obtained by traditional methods.In other words,fractal theory delineates large anomalous district,including weak anomalous regions.The geochemical information obtained is more reasonable and comprehensive.(4)Fractal theory provides an effective method for the processing and analysis of ground gamma survey data,and it is a good effect on the analysis of metallogenic anomalies and prospecting areas,which is worthy of further study.