Barite Mine Design Using Integrated Surface Geophysical Surveying and Modeling

Surface geophysical measurements of resistivity, magnetic and gravity were evaluated in combination along same traverses to detect and quantify ore reserves in order to enable the design of effective and sustainable mining strategy for some remote barite fields in the Abakaliki basin, southeastern Nigeria. In addition to the surface geophysical measurements, geological field mapping of ores bodies and host rocks were undertaken to calibrate geophysical models. Numerical modeling and geological interpretation of the geophysical data indicate and delineate zones of ore occurrences and provide ore tonnage estimates for the studied fields. However, tonnage estimates in some regions were severely flawed as demonstrated by some consequent futile surface excavations. The failure recorded by the open excavated pits is linked to the pitfalls in some ore quantity estimates that bear largely on survey layout design and significant errors emanating from data interpretation due to complex structural and stratigraphic setting of ore incidence, all of which contributed to constrain the reliability on the geophysical data alone as a mine design tool. Best practice necessitates that excavation designs are to be preceded by exploratory drilling to ascertain proven reserves.