oa Refraction tomography at the Nova Ni-Cu mine

The mining industry is increasingly using 3D seismic reflection datasets, from project genesis through to mature mine sites. During processing of the reflection data, the refracted arrival is digitised and used to correct for nearsurface velocity variations. By performing a 3D inversion of these first arrivals, a high-resolution, tomographic velocity model can be obtained that provides additional information in the top portion of the seismic volume.

The Nova Operation, owned by IGO, is located in the Fraser Range of Western Australia. The Nova-Bollinger ore bodies are magmatic Ni-Cu deposits being mined from within an eye-like structure visible on magnetic datasets. In 2018, a 60 sqkm seismic reflection survey was acquired over the Nova mining lease to assist in exploration. The velocity model derived from the refraction tomography provided useful information in the near-surface, including insights into hydrogeology and the base of the cover. When compared to current models created from drilling and AEM, additional detail can be observed, including additional palaeochannels in the southeast.