Multivariate anomaly modeling of primary geochemical halos by U-spatial statistic algorithm development: A case study from the Sari Gunay epithermal gold deposit, Iran
| Autor: | Sajjad Talesh Hosseini, Omid Asghari, Hooshang Asadi Haroni |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Multivariate statistics
Spatial correlation 020209 energy Anomaly (natural sciences) Autocorrelation Geology 02 engineering and technology 010502 geochemistry & geophysics 01 natural sciences Geochemistry and Petrology 0202 electrical engineering electronic engineering information engineering Economic Geology Spurious relationship Compositional data Variogram Algorithm Statistic 0105 earth and related environmental sciences |
| Zdroj: | Ore Geology Reviews. 127:103845 |
| ISSN: | 0169-1368 |
| DOI: | 10.1016/j.oregeorev.2020.103845 |
| Popis: | An accurate separation of anomalous areas (values) in primary geochemical halos with heterogeneous spatial variations requires an appropriate algorithm that considers the complex patterns and multivariate relationships of the input geochemical data. There are several problems in multivariate modeling of geochemical compositional data, because such data present spurious values of spatial correlation between the variables. To address this problem, this paper proposes an improved U-spatial statistic algorithm for 3D multivariate anomaly modeling of the geochemical dataset with compositional nature at the Sari Gunay epithermal gold deposit, NW Iran. To perform 3D multivariate modeling, isometric logarithmic ratio (ilr), as an effective method to transform compositional data from the simplex to real space, and minimum/maximum autocorrelation factor (MAF), as a multivariate geostatistical method, were used in an integrated analysis. In comparison to the other separation techniques, this integrated approach has an advantage to control the heterogeneous spatial variations in the input data. In this approach, we improved the U-spatial statistic method by using the variogram tool theory. By using this approach, we identified the primary geochemical haloes associated with Au-As-Sb-Hg front halo elements, Cu-Ag-Pb near-ore halo elements and Ni-Co tail halo elements at the Sari Gunay gold depsoit. The results were validated by using contrast coefficient and exploratory index tools. By examining the 3D multivariate primary anomalous geochemical halos, zones of possible hidden epithermal gold and porphyry copper–gold mineralizations were recognized at this deposit for future exploration. |
| Databáze: | OpenAIRE |
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