|
|
A COMPARISON OF SEVERAL THRESHOLD DETERMINATION METHODS IN GEOCHEMICAL DATA PROCESSING: A CASE STUDY OF STREAM SEDIMENTS IN CHABAQI AREA OF INNER MONGOLIA |
DAI Hui-min 1,GONG Chuan-dong 2,BAO Qing-zhong 1,SUN Zhong-ren 1,YOU Hong-liang 1,JIN Xin 1,GAO Fei 1 |
1. Shenyang Institute of Geology and Mineral Resources, Shenyang 110034, China;2. Production Safety Supervision and Administration of Dongling District, Shenyang, Shenyang 110000, China |
|
|
Abstract The authors made statistic calculation of stream sediment data using such means as traditional statistics, robust estimation,cumulative percentage of 85% and multifractal statistical method in Chabaqi area and compared the thresholds obtained by the four methods. The thresholds of the same elements obtained by the four methods are obviously different from each other. The thresholds calculated by the cumulative percentage statistics are lowest except for lead, and the thresholds calculated by the other three methods fail to show obvious regularity.The results are closely related to the distribution characteristics of the geochemical data and the statistical methods used. Comparing the anomaly characteristics with the geological characteristics, the authors have found that, although weak and gentle geochemical anomalies will be mostly detected by cumulative percentage of 85%, the larger anomaly areas will bring difficulties to anomaly inspection in the field. It is therefore thought that the thresholds obtained by multifractal statistical method are suitable for the study area. A comparative study of the thresholds has led the authors to believe that the reasonable method must be combined with the actual geological conditions and based on a thorough study of the geological background of the study area.
|
Received: 16 October 2009
Published: 16 December 2010
|
|
|
|
|
|
|
|