oa Determination Of Ore body Continuity By A 2.5-D Resistivity Tomography Method

The electrical resistivity method has been used in the exploration industry for many years. However, it is mainly used on surface surveys and has not been applied extensively in crosshole situations. Two reasons for this are that there is not a very good inversion technique developed for crosshole geometries and there is not a good way to display crosshole survey data like pseudosections in surface surveys. But the need for detecting geological structures between two boreholes in the mining industry is urgent.

Here we present a few examples for detecting ore body continuity with the 2.5D resistivity tomography method. Firstly, we produce a few sets of borehole numerical modelling data for different models, with our 2.5D FEM resistivity modelling program. Then, our 2.5D FEM resistivity inversion program is used to invert the model data to obtain the resistivity distribution between the two boreholes. The three examples show that 2.5D resistivity inversion can clearly detect the ore body continuity between two boreholes from simple bipole bipole scanning data. The technique can be very easily used in exploration and is most useful for mining purposes to delineate the structure between boreholes.