
%0 Journal Article
%A Williams, Nicholas 
%A Wet, Barry de 
%A Kekana, Sello 
%A Nielsen, Shane 
%A Broughton, David 
%T Applying Advanced Gravity and Magnetic Inversion Methods to Expand the Platreef PGE-Ni-Cu Resource in the Bushveld Complex
%J ASEG Extended Abstracts
%D 2016/08/24
%V 2016
%N 1
%P 1-7
%K 
%R https://doi.org/10.1071/ASEG2016AB187
%U https://www.publish.csiro.au/paper/ASEG2016AB187 
%X There are many potential field inversion algorithms available, and all are sufficiently capable of generating a model that explains supplied geophysical observations. The challenge is extracting a model that provides real geological insight. Here we present applications of two different styles of advanced inversions to a deep exploration program at the Platreef PGE-Ni-Cu deposit in the Bushveld Igneous Complex of South Africa. The initial approach was to apply generalised focussing constraints to a 3D magnetic vector inversion, an approach chosen to manage the effect of expected strong remanent magnetisation. This resulted in successful prediction and drill definition of inferred resources within a deep, west-dipping extension to the shallow-dipping &#x201c;Flatreef&#x201d; deposit. Later, a detailed 3D model of geological constraints based on drilling and mapping was constructed and used to tightly constrain inversions of gravity data derived from a FALCON airborne gravity gradiometer survey. The resulting 3D density model accurately predicted a continuation of the Flatreef host rocks to shallower levels than previously anticipated. This facilitated further drill-definition of additional inferred resources within a southern extension of the Flatreef deposit. Key to the success of the inversions at accurately targeting mineralisation at depths of 700&#x2013;1300 m depth, was the inclusion and integration of all available information to ensure that predictions were consistent with prior observations. 
