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| Study on feature of high natural gamma anomaly and main controlling factors in Ordos basin |
| Tan Cheng-qian1,2,3, Liu Chi-yang1, Zhao Jun-long2, Zhang Rong-rong1 |
| Geologic Engineering and Mapping Engineering Institute, Chang’an University, Xi’an City, Shanxi Province. 710054, China |
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Abstract In order to know the main controlling factors of high natural gamma anomaly in shallow and deep parts of Ordos basin, after studying the planar and vertical distribution feature of high natural gamma anomaly in the area from the aspects of correlation of logging traces in single hole and typical logging traces, analysis of planar distribution feature of high natural gamma anomaly in different strata and test analysis of the contents of radioelement, the paper considered: ①good correlation exists between the change of uranium contents and variation of natural gamma amplitude.The natural gamma anomaly mainly directly resulted from increasing the uranium content, and uranium activate and accumulation have certain regional difference; ②the planar feature of natural gamma anomaly is closely relative to stratigraphic sedimentary feature; ③the main controlling factors resulted in high natural gamma anomaly in the basin are changes of sedimentary environment and experienced structural movement, which further determined the feature of uranium time-space distribution, and uranium anomaly in shallow and deep parts of the basin also has some influence.
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Received: 21 February 2006
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2007, Vol. 42 
