Using the data separation technology

based on the data extracted from the 1:250000 available and regional geochemical data of the content of natural radionuclide(238U

232Th

40K) in different type soil in Chengdu Economic Area

field sampling and analysis were carried out. Then

the distrbution characteristics of natural radionuclide content in different type soil were studied in this area. The results showed that:(1) The contents of natural radionuclides in the area soil were at the same level with the world

the whole nation and Sichuan Province.(2) The contents of 238U in yellow soil

brown soil

purple soil

paddy soil

gray soil and grass mat soil were 3.18

2.40

2.12

2.45

2.48

2.73

respectively

the average was 30.41(the unit was 10-6 g/g); the contents of 232Th were 14.27

14.64

11.67

13.98

13.41

14.09

the average was 54.35(10-6 g/g); the contents of 40K were 2.06

2.38

1.94

1.74

1.83

2.22

the average was 1.98(10-2 g/g);(3) The contents of natural radionuclides in different type soil showed up the rules as following:the content of 238U in yellow soil >grass mat soil >gray damp soil >paddy soil >brown soil >purple soil; the content of 232Th in brown soil >yellow soil >grass mat soil >paddy soil >gray damp soil >purple soil; the content of 40K in brown soil >grass mat soil >yellow soil >purple soil >gray damp soil >paddy soil;(4) In the same type soil

the natural radionuclide content of plain soil was lower than that of mountain.