Detailed orebody mapping using borehole radar

Abstract

Detailed orebody delineation on a mine scale is usually carried out predominantly by the interpretation of information from drillhole core and cuttings. Inaccurate interpolations between drillholes can result in dilution and ore loss. This paper presents examples of the use of borehole radar to provide more continuous maps of nickel sulphide orebody outlines in Western Australia. These examples show that these maps can substantially reduce the uncertainty of orebody models resulting in improved mine plans, reduced dilution and improved ore recovery. The data presented were collected with the GeoMole borehole radar system. This system is not directional. However, by combining information from other sources, the 3D locations of the reflectors that are imaged can often be accurately estimated and the potential errors quantified. Difficulties have been encountered when the system has been operated in salt water filled holes but good results have been obtained in these holes after they have been flushed with fresh water. The system has also been used in up-dipping holes up to 120 m long. The results obtained to date indicate that substantial cost benefits can be obtained at some mine sites by incorporating borehole radar surveys into the ore delineation process.