Geological modeling and estimation of a Bekisopa iron deposit, Madagascar

Abstract

This study aims to carry out an in-depth analysis of the geology of the iron deposit in question and to explore its exploitation potential. By combining field observations, drilling operations, geological analyzes and the use of modeling tools, our intention is to achieve an in-depth understanding of the composition, distribution and geological characteristics of the iron deposit of Bekisopa discovered by H. Besairie in 1933. The evaluation of iron reserves was carried out by applying geostatistical methods, in particular kriging. Data from drilling, together with geological information from three-dimensional models, were used to establish variograms and spatial continuity models. This approach made it possible to arrive at a quantitative estimate of the iron reserves present in the deposit. A total of thirty boreholes were carried out over an area of one square kilometer. These drilling data were crucial to calculate a volume of the deposit of around 25,000,000 cubic meters, taking into account an average density of the deposit of 4,500 kg/m3 and an average grade of 40%. This estimate led to a value of ferrous resources of around forty million (40,000,000) tonnes. Given that the ore is at a relatively accessible depth on the surface, the option of open pit mining presents itself as a feasible and attractive alternative. This type of mining involves extracting ore from large open pits, an economically viable approach when mineral resources are located near the surface.