| Citation: | Shu-yun XIE, Qiu-ming CHENG, Xian-zhong KE, Zheng-yu BAO, Zhang-ming WANG, Hao-li QUAN. Identification of Geochemical Anomaly by Multifractal Analysis. Journal of Earth Science, 2008, 19(4): 334-342.
|
The separation of anomalies from geochemical background is an important part of data analysis because lack of such identifications might have profound influence on or even distort the final analysis results. In this article, 1 672 geochemical analytical data of 11 elements, including Cu, Mo, Ag, Sn, and others, from a region within Tibet, South China, are used as one example. Together with the traditional anomaly recognition method of using the iterative mean ±2σ, local multifractality theory has been utilized to delineate the ranges of geochemical anomalies of the elements. To different degrees, on the basis of original data mapping, C-A fractal analysis and singularity exponents, Sn differs from the other 10 elements. Moreover, geochemical mapping results based on values of the multifractal asymmetry index for all elements delineate the highly anomalous area. Similar to other 10 elements, the anomalous areas of Sn delineated by the asymmetry index distribute along the main structure orientations. According to the asymmetry indexes, the 11 elements could be classified into 3 groups: (1) Ag and Au, (2) As-Sb-Cu-Pb-Zn-Mo, and (3) Sn-Bi-W. This paragenetic association of elements can be used to interpret possible origins of mineralization, which is in agreement with petrological analysis and field survey results.
| Agterberg, F. P., 2001. Multifractal Simulation of Geochemical Map Patterns. Proceedings of the International Symposium on Diversity of Mineralization and Its Prediction and Assessment, Beijing and Wuhan. 6-14. |
| Bao, Z. Y., Li, F. L., Jia, X. Q., 1999. Methodology of Temporal-Spatial Structure of Geochemical Fields. Earth Science—Journal of China University of Geosciences, 24 (3): 282-286 (in Chinese with English Abstract). |
| Cheng, Q., 1995. The Perimeter-Area Fractal Model and Its Application to Geology. Mathematical Geology, 27 (1): 69-82. doi: 10.1007/BF02083568 |
| Cheng, Q., 1999. Spatial and Scaling Modeling for Geochemical Anomaly Separation. Journal of Geochemical Exploration, 65 (3): 175-194. doi: 10.1016/S0375-6742(99)00028-X |
| Cheng, Q., 2000. GeoData Analysis System (GeoDAS) for Mineral Exploration: User's Guide and Exercise Manual, Material for the Training Workshop on GeoDAS Held at York University, Toronto, Canada, 1, 3, 204. http://www.gisworld.org/geodas. |
| Cheng, Q., 2007. Mapping Singularities with Stream Sediment Geochemical Data for Prediction of Undiscovered Mineral Deposits in Gejiu, Yunnan Province, China. Ore Geology Reviews, 32: 314-324. doi: 10.1016/j.oregeorev.2006.10.002 |
| Cheng, Q., Agterberg, F. P., Ballatyne, S. B., 1994. The Separation of Geochemical Anomalies from Background by Fractal Methods. Journal of Exploration Geochemistry, 51: 109-130. doi: 10.1016/0375-6742(94)90013-2 |
| Evertsz, C. J. G., Mandelbrot, B. B., 1992. Multifractal Measures (Appendix B). In: Peitgen, H. O., Jurgens, H., Saupe, D., eds., Chaos and Fractals. Springer Verlag, New York. 922-953. |
| Gałuszka, A., 2007. A Review of Geochemical Background Concepts and an Example Using Data from Poland. Environmental Geology, 52 (5): 861-870. doi: 10.1007/s00254-006-0528-2 |
| Halsey, T. C., Jensen, M. H., Kadanoff, L. P., et al., 1986. Fractal Measures and Their Singularities—The Characterization of Strange Sets. Physical Review A, 33 (2): 1141-1151. doi: 10.1103/PhysRevA.33.1141 |
| Hawkes, H. E., Webb, J. S., 1962. Geochemistry in Mineral Exploration. Harper and Row, New York. |
| Kravchenko, N, A., Boast, W. C., Bullock, G. D., 1999. Multifractal Analysis of Soil Spatial Variability. Agronomy Journal, 91: 1033-1041. doi: 10.2134/agronj1999.9161033x |
| Li, C., Ma, T., Shi, J., 2003. Application of a Fractal Method Relating Concentrations and Distances for Separation of Geochemical Anomalies from Background. Journal of Geochemical Exploration, 77: 167-175. doi: 10.1016/S0375-6742(02)00276-5 |
| Li, F. L., Bao, Z. Y., Pei, T., et al., 1999. Principle and Software System of Geological and Geochemical Data Processing. Earth Science—Journal of China University of Geosciences, 24 (3): 316-319 (in Chinese with English Abstract). |
| Lima, A., De Vivo, B., Cicchella, D., et al., 2003. Multifractal IDW Interpolation and Fractal Filtering Method in Environmental Studies: An Application on Regional Stream Sediments of (Italy), Campania Region. Applied Geochemistry, 18 (12): 1853-1865. doi: 10.1016/S0883-2927(03)00083-0 |
| Liu, C. M, Hu, S. Q., 2003. Characteristics of Geochemical Anomalies in the Qulong Porphyry Cu-Mo Deposit of Tibet. Geophysical and Geochemical Exploration, 27 (6): 441-444 (in Chinese with English Abstract). |
| MacQueen, J. B., 1967. Some Methods for Classification and Analysis of Multivariate Observations. Proceedings of 5-th Berkeley Symposium on Mathematical Statistics and Probability. University of California Press, Berkeley. 281-297. |
| Mandelbrot, B. B., 1975. Stochastic Models for the Earth's Relief, the Shape and the Fractal Dimension of the Coastlines, and the Number-Area Rule for Islands. Proceedings of the National Academy of Sciences (USA), 72: 3825-3828. doi: 10.1073/pnas.72.10.3825 |
| Matschullat, J., Ottenstein, R., Reimann, C., 2000. Geochemical Background: Can We Calculate It? Environmental Geology, 39 (9): 990-1000. doi: 10.1007/s002549900084 |
| Reimann, C., Filzmoser, P., Garrett, G. R., 2005. Background and Threshold: Critical Comparison of Methods of Determination. Science of the Total Environment, 346: 1-16. doi: 10.1016/j.scitotenv.2004.11.023 |
| Schwertman, N. C., Owens, M. A., Adnan, R., 2004. A Simple More General Boxplot Method for Identifying Outliers. Computational Statistics & Data Analysis, 47 (1): 165-174. |
| Schwertman, N. C., Silva, D. R., 2007. Identifying Outliers with Sequential Fences. Computational Statistics & Data Analysis, 51 (8): 3800-3810. |
| Stanley, C. R., Sinclair, A. J., 1989. Comparison of Probability Plots and Gap Statistics in the Selection of Threshold for Exploration Geochemistry Data. Journal of Geochemical Exploration, 32: 355-357. doi: 10.1016/0375-6742(89)90076-9 |
| Tukey, J. W., 1997. Exploratory Data Analysis, Reading. Addison-Wesley Publishing Company, Massachusetts. |
| Xie, S., Bao, Z., 2004. Fractal and Multifractal Properties of Geochemical Fields. Mathematical Geology, 36 (7): 847-864. doi: 10.1023/B:MATG.0000041182.70233.47 |
| Xie, S., Cheng, Q., Chen, G., et al., 2007a. Application of Local Singularity in Prospecting Oil/Gas Potential Targets. Nonlinear Processes in Geophysics, 14: 285-294. doi: 10.5194/npg-14-285-2007 |
| Xie, S., Bao, Z., Zhang, J., et al., 2007b. Local Multifractality and Its Implication for Geochemical Environment Assessment. Journal of China University of Geosciences, 18 (Special Issue): 158-159. |
| Xu, Y. G., Cheng, Q., 2001. A Fractal Filtering Technique for Processing Regional Geochemical Maps for Mineral Exploration. Geochemistry—Exploration, Environment, Analysis, 1: 147-156. doi: 10.1144/geochem.1.2.147 |
| Zhang, L. P., Bai, G. P., Zhao, K. B., et al., 2006. Restudy of Acid-Extractable Hydrocarbon Data from Surface Geochemical Survey in the Yimeng Uplift of the Ordos Basin, China: Improvement of Geochemical Prospecting for Hydrocarbons. Marine and Petroleum Geology, 23 (5): 529-542. doi: 10.1016/j.marpetgeo.2006.04.003 |
Figures(8)
Copyright © 2013-2020 Journal of Earth Science 鄂ICP备15021562号-2
Tel: +86-27-67885075 Fax: +86-27-67885075 E-mail: xbb@cug.edu.cn
Address: Editorial Office of Journal, China University of Geosciences, Yujiashan, Wuhan, Hubei 430074, P. R. China
Supported by:
Beijing Renhe Information Technology Co. Ltd
E-mail:
info@rhhz.net
DownLoad:
