Geobody Estimation by Bhattacharyya Method Utilizing Nonlinear Inverse Modeling of Magnetic Data in Baba-Ali Iron Deposit, NW Iran

Abstract

Geophysical investigations are one of the leading efforts in any exploration project that must be performed ahead of time due to the high excavation expenditures, heavy machinery, and cost reduction. One of the essential geophysical concerns is the estimation of the physical and geometrical parameters of the reserve (geobody), which is done by exploiting the nonlinear inverse modeling of magnetic data. These parameters include depth, volume, shape factor, and type of storage. The present investigation aims to prepare and model magnetic data for proposed drilling sites in the Baba Ali Iron ore deposit in the Hamedan province of Iran. The areal and depth extent of the iron ore geobody was unknown. The Bhattacharyya method by MATLAB software coding was used to minimize the target function and potential field data and create the best fit for the magnetic data. The residual anomaly and model graphs exhibited an excellent two-dimensional conformation in this modeling. Also, 3D modeling correctly reconstructs the properties of the productive resources of anomalies. After preparing full magnetic maps, the magnetic lenses distinguished in four anomalies of surface depths, 20, 50, and deeper than 50 meters for this zone. This magnetite lens for the first zone was estimated based on filters applied on the entire magnetic map so that the lens's depth is trivial and almost zero. Their specific gravity is calculated as 4.77 t/m3, and their initial storage capacity is suggested to be about 95,400 tones at most. Finally, to complete the preliminary explorations of the specified area, exploratory drilling is suggested for three points by inverse modeling.