Articles | Volume 19, issue 2
Nonlin. Processes Geophys., 19, 283–289, 2012
https://doi.org/10.5194/npg-19-283-2012

Special issue: Nonlinearity, scaling and complexity in exploration...

Nonlin. Processes Geophys., 19, 283–289, 2012
https://doi.org/10.5194/npg-19-283-2012

Research article 16 Apr 2012

Research article | 16 Apr 2012

Identification of uranium targets based on airborne radiometric data analysis by using multifractal modeling, Tark and Avanligh 1:50 000 sheets, NW Iran

P. Afzal1,3, A. Zia Zarifi2, and A. Bijan Yasrebi3 P. Afzal et al.
  • 1Department of Mining Engineering, South Tehran branch, Islamic Azad University, Tehran, Iran
  • 2Department of Mining Engineering, Lahijan Branch, Islamic Azad University, Lahijan, Iran
  • 3Camborne School of Mines, University of Exeter, Penryn, UK

Abstract. Airborne geophysical anomaly separation using conventional statistics and the fractal/multifractal concentration-area (C-A) method has been applied to the Tark and Avanligh 1:50 000 sheets in NW Iran. The geophysical survey that resulted in the airborne geophysical data was conducted for uranium exploration in both areas. Selected anomalies were further investigated by using surface radiometric data. Firstly, threshold values to define anomalies were determined and compared by means of conventional statistical methods. Several relatively large anomalies were identified with uranium (U) equal to 1.7 eppm and 1.9 eppm in the Tark and Avanligh areas, respectively; locally these U anomalies have magnitudes exceeding 3.5 eppm in both areas. Log-log plots obtained for the C-A method indicate existence of two separate stages of U enrichment, with a major event being the cause of U concentration values above 6.1 and 3.4 eppm in the Tark and Avanligh areas, respectively. These higher intensity anomalies are located in the northwestern part of the Tark and in the southern part of the Avanligh sheets. In both areas, the C-A anomalies were further investigated using ground radiometric data and XRF analysis revealing higher than 150 and 280 ppm U concentration values in the two areas, respectively. Correlation between the anomalies and geological units show that the anomalies are associated with limestone and sandstone units.