Abstract

ARAYA, Luis  and  LLATAS, Isabel. VARIOGRAM ANALYSIS OF PERCENTAGES OF SILICA, ALUMINA, LOSS ON IGNITION, MANGANESE AND PHOSPHORUS IN THE IRON ORES OF CERRO SAN JOAQUIN, BOLIVARIAN MUNICIPALITY ANGOSTURA, BOLIVAR STATE. bol.geol. [online]. 2015, vol.37, n.2, pp.89-95. ISSN 0120-0283.

The purpose of this paper is to analyze the variograms of chemical variables that accompany iron ore present in the Cerro San Joaquin, Ciudad Piar, Bolívar state. The data used correspond to campaigns conducted exploratory wells on the hill above. The methodology used in this study was first exploratory statistical analysis of the chemical composition of the ores. Then Variogram map is constructed to detect the directions of anisotropy, and the experimental variograms were calculated on the primary and secondary directions for each variable. Finally, theoretical variogram models were fitted in the obtained experimental variograms. The results show that the chemical composition is lognormal, with geometric anisotropy parallel to the main direction in topography sense Northwest - Southeast, with the exception of manganese that is Northeast - Southwest. In the direction normal to the topography, anisotropy is zonal. The theoretical variograms were logarithmically transformed spherical nested exponential-type dependence with ranges between 120 m and 480 m. We conclude that the reservoir may be comprised of mineralized stratifications with large spatial correlation that gradually decreases with increasing distance between one point and another stratum

Keywords : Cerro San Joaquín; variograms; iron ore; anisotropy.

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